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Tim Bell 2009-07-31 17:19:38 -07:00
commit 6b6386f999
55 changed files with 4089 additions and 643 deletions
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2
jdk/make/java/java/FILES_java.gmk
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@ -250,6 +250,8 @@ JAVA_JAVA_java = \
java/util/IdentityHashMap.java \
java/util/EnumMap.java \
java/util/Arrays.java \
java/util/TimSort.java \
java/util/ComparableTimSort.java \
java/util/ConcurrentModificationException.java \
java/util/ServiceLoader.java \
java/util/ServiceConfigurationError.java \

2
jdk/src/share/classes/java/nio/channels/DatagramChannel.java
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@ -421,7 +421,7 @@ public abstract class DatagramChannel
* invocation of this method will block until the first operation is
* complete. If this channel's socket is not bound then this method will
* first cause the socket to be bound to an address that is assigned
* automatically, as if by invoking the {@link #bind bind) method with a
* automatically, as if by invoking the {@link #bind bind} method with a
* parameter of {@code null}. </p>
*
* @param src

4
jdk/src/share/classes/java/nio/channels/package-info.java
View File

@ -115,8 +115,8 @@
* <td>Reads, writes, maps, and manipulates files</td></tr>
* <tr><td valign=top><tt>{@link java.nio.channels.FileLock}</tt></td>
* <td>A lock on a (region of a) file</td></tr>
* <tr><td valign=top><tt>{@link java.nio.MappedByteBuffer}/{@link java.nio.MappedBigByteBuffer}&nbsp;&nbsp;</tt></td>
* <td>A direct byte buffer or big byte buffer mapped to a region of a&nbsp;file</td></tr>
* <tr><td valign=top><tt>{@link java.nio.MappedByteBuffer}&nbsp;&nbsp;</tt></td>
* <td>A direct byte buffer mapped to a region of a&nbsp;file</td></tr>
* </table></blockquote>
*
* <p> The {@link java.nio.channels.FileChannel} class supports the usual

2
jdk/src/share/classes/java/nio/file/DirectoryStream.java
View File

@ -53,7 +53,7 @@ import java.io.IOException;
* invoking the {@link #close close} method. Closing the directory stream
* releases any resources associated with the stream. Once a directory stream
* is closed, all further method invocations on the iterator throw {@link
* java.util.concurrent.ConcurrentModificationException} with cause {@link
* java.util.ConcurrentModificationException} with cause {@link
* ClosedDirectoryStreamException}.
*
* <p> A directory stream is not required to be <i>asynchronously closeable</i>.

2
jdk/src/share/classes/java/nio/file/Path.java
View File

@ -987,7 +987,7 @@ public abstract class Path
* exception then it is propogated to the iterator's {@link Iterator#hasNext()
* hasNext} or {@link Iterator#next() next} method. Where an {@code
* IOException} is thrown, it is propogated as a {@link
* java.util.concurrent.ConcurrentModificationException} with the {@code
* java.util.ConcurrentModificationException} with the {@code
* IOException} as the cause.
*
* <p> When an implementation supports operations on entries in the

4
jdk/src/share/classes/java/nio/file/attribute/package-info.java
View File

@ -102,9 +102,9 @@
* <p><li> The {@link java.nio.file.attribute.UserPrincipalLookupService}
* interface defines methods to lookup user or group principals. </li>
*
* <p><li> The {@link java.nio.file.attribute.Attribute} interface
* <p><li> The {@link java.nio.file.attribute.FileAttribute} interface
* represents the value of an attribute for cases where the attribute value is
* require to be set atomically when creating an object in the file system. </li>
* required to be set atomically when creating an object in the file system. </li>
*
* </ul>
*

277
jdk/src/share/classes/java/util/Arrays.java
View File

@ -1065,29 +1065,103 @@ public class Arrays {
(x[b] > x[c] ? b : x[a] > x[c] ? c : a));
}
/**
* Old merge sort implementation can be selected (for
* compatibility with broken comparators) using a system property.
* Cannot be a static boolean in the enclosing class due to
* circular dependencies. To be removed in a future release.
*/
static final class LegacyMergeSort {
private static final boolean userRequested =
java.security.AccessController.doPrivileged(
new sun.security.action.GetBooleanAction(
"java.util.Arrays.useLegacyMergeSort")).booleanValue();
}
/*
* If this platform has an optimizing VM, check whether ComparableTimSort
* offers any performance benefit over TimSort in conjunction with a
* comparator that returns:
* {@code ((Comparable)first).compareTo(Second)}.
* If not, you are better off deleting ComparableTimSort to
* eliminate the code duplication. In other words, the commented
* out code below is the preferable implementation for sorting
* arrays of Comparables if it offers sufficient performance.
*/
// /**
// * A comparator that implements the natural ordering of a group of
// * mutually comparable elements. Using this comparator saves us
// * from duplicating most of the code in this file (one version for
// * Comparables, one for explicit Comparators).
// */
// private static final Comparator<Object> NATURAL_ORDER =
// new Comparator<Object>() {
// @SuppressWarnings("unchecked")
// public int compare(Object first, Object second) {
// return ((Comparable<Object>)first).compareTo(second);
// }
// };
//
// public static void sort(Object[] a) {
// sort(a, 0, a.length, NATURAL_ORDER);
// }
//
// public static void sort(Object[] a, int fromIndex, int toIndex) {
// sort(a, fromIndex, toIndex, NATURAL_ORDER);
// }
/**
* Sorts the specified array of objects into ascending order, according to
* the {@linkplain Comparable natural ordering}
* of its elements. All elements in the array
* must implement the {@link Comparable} interface. Furthermore, all
* elements in the array must be <i>mutually comparable</i> (that is,
* <tt>e1.compareTo(e2)</tt> must not throw a <tt>ClassCastException</tt>
* for any elements <tt>e1</tt> and <tt>e2</tt> in the array).<p>
* Sorts the specified array of objects into ascending order, according
* to the {@linkplain Comparable natural ordering} of its elements.
* All elements in the array must implement the {@link Comparable}
* interface. Furthermore, all elements in the array must be
* <i>mutually comparable</i> (that is, {@code e1.compareTo(e2)} must
* not throw a {@code ClassCastException} for any elements {@code e1}
* and {@code e2} in the array).
*
* This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.<p>
* <p>This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.
*
* The sorting algorithm is a modified mergesort (in which the merge is
* omitted if the highest element in the low sublist is less than the
* lowest element in the high sublist). This algorithm offers guaranteed
* n*log(n) performance.
* <p>Implementation note: This implementation is a stable, adaptive,
* iterative mergesort that requires far fewer than n lg(n) comparisons
* when the input array is partially sorted, while offering the
* performance of a traditional mergesort when the input array is
* randomly ordered. If the input array is nearly sorted, the
* implementation requires approximately n comparisons. Temporary
* storage requirements vary from a small constant for nearly sorted
* input arrays to n/2 object references for randomly ordered input
* arrays.
*
* <p>The implementation takes equal advantage of ascending and
* descending order in its input array, and can take advantage of
* ascending and descending order in different parts of the the same
* input array. It is well-suited to merging two or more sorted arrays:
* simply concatenate the arrays and sort the resulting array.
*
* <p>The implementation was adapted from Tim Peters's list sort for Python
* (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
* TimSort</a>). It uses techiques from Peter McIlroy's "Optimistic
* Sorting and Information Theoretic Complexity", in Proceedings of the
* Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
* January 1993.
*
* @param a the array to be sorted
* @throws ClassCastException if the array contains elements that are not
* <i>mutually comparable</i> (for example, strings and integers).
* @throws ClassCastException if the array contains elements that are not
* <i>mutually comparable</i> (for example, strings and integers)
* @throws IllegalArgumentException (optional) if the natural
* ordering of the array elements is found to violate the
* {@link Comparable} contract
*/
public static void sort(Object[] a) {
if (LegacyMergeSort.userRequested)
legacyMergeSort(a);
else
ComparableTimSort.sort(a);
}
/** To be removed in a future release. */
private static void legacyMergeSort(Object[] a) {
Object[] aux = a.clone();
mergeSort(aux, a, 0, a.length, 0);
}
@ -1097,34 +1171,63 @@ public class Arrays {
* ascending order, according to the
* {@linkplain Comparable natural ordering} of its
* elements. The range to be sorted extends from index
* <tt>fromIndex</tt>, inclusive, to index <tt>toIndex</tt>, exclusive.
* (If <tt>fromIndex==toIndex</tt>, the range to be sorted is empty.) All
* {@code fromIndex}, inclusive, to index {@code toIndex}, exclusive.
* (If {@code fromIndex==toIndex}, the range to be sorted is empty.) All
* elements in this range must implement the {@link Comparable}
* interface. Furthermore, all elements in this range must be <i>mutually
* comparable</i> (that is, <tt>e1.compareTo(e2)</tt> must not throw a
* <tt>ClassCastException</tt> for any elements <tt>e1</tt> and
* <tt>e2</tt> in the array).<p>
* comparable</i> (that is, {@code e1.compareTo(e2)} must not throw a
* {@code ClassCastException} for any elements {@code e1} and
* {@code e2} in the array).
*
* This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.<p>
* <p>This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.
*
* The sorting algorithm is a modified mergesort (in which the merge is
* omitted if the highest element in the low sublist is less than the
* lowest element in the high sublist). This algorithm offers guaranteed
* n*log(n) performance.
* <p>Implementation note: This implementation is a stable, adaptive,
* iterative mergesort that requires far fewer than n lg(n) comparisons
* when the input array is partially sorted, while offering the
* performance of a traditional mergesort when the input array is
* randomly ordered. If the input array is nearly sorted, the
* implementation requires approximately n comparisons. Temporary
* storage requirements vary from a small constant for nearly sorted
* input arrays to n/2 object references for randomly ordered input
* arrays.
*
* <p>The implementation takes equal advantage of ascending and
* descending order in its input array, and can take advantage of
* ascending and descending order in different parts of the the same
* input array. It is well-suited to merging two or more sorted arrays:
* simply concatenate the arrays and sort the resulting array.
*
* <p>The implementation was adapted from Tim Peters's list sort for Python
* (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
* TimSort</a>). It uses techiques from Peter McIlroy's "Optimistic
* Sorting and Information Theoretic Complexity", in Proceedings of the
* Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
* January 1993.
*
* @param a the array to be sorted
* @param fromIndex the index of the first element (inclusive) to be
* sorted
* @param toIndex the index of the last element (exclusive) to be sorted
* @throws IllegalArgumentException if <tt>fromIndex &gt; toIndex</tt>
* @throws ArrayIndexOutOfBoundsException if <tt>fromIndex &lt; 0</tt> or
* <tt>toIndex &gt; a.length</tt>
* @throws ClassCastException if the array contains elements that are
* not <i>mutually comparable</i> (for example, strings and
* integers).
* @throws IllegalArgumentException if {@code fromIndex > toIndex} or
* (optional) if the natural ordering of the array elements is
* found to violate the {@link Comparable} contract
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0} or
* {@code toIndex > a.length}
* @throws ClassCastException if the array contains elements that are
* not <i>mutually comparable</i> (for example, strings and
* integers).
*/
public static void sort(Object[] a, int fromIndex, int toIndex) {
if (LegacyMergeSort.userRequested)
legacyMergeSort(a, fromIndex, toIndex);
else
ComparableTimSort.sort(a, fromIndex, toIndex);
}
/** To be removed in a future release. */
private static void legacyMergeSort(Object[] a,
int fromIndex, int toIndex) {
rangeCheck(a.length, fromIndex, toIndex);
Object[] aux = copyOfRange(a, fromIndex, toIndex);
mergeSort(aux, a, fromIndex, toIndex, -fromIndex);
@ -1133,6 +1236,7 @@ public class Arrays {
/**
* Tuning parameter: list size at or below which insertion sort will be
* used in preference to mergesort or quicksort.
* To be removed in a future release.
*/
private static final int INSERTIONSORT_THRESHOLD = 7;
@ -1142,6 +1246,7 @@ public class Arrays {
* low is the index in dest to start sorting
* high is the end index in dest to end sorting
* off is the offset to generate corresponding low, high in src
* To be removed in a future release.
*/
private static void mergeSort(Object[] src,
Object[] dest,
@ -1197,25 +1302,53 @@ public class Arrays {
* Sorts the specified array of objects according to the order induced by
* the specified comparator. All elements in the array must be
* <i>mutually comparable</i> by the specified comparator (that is,
* <tt>c.compare(e1, e2)</tt> must not throw a <tt>ClassCastException</tt>
* for any elements <tt>e1</tt> and <tt>e2</tt> in the array).<p>
* {@code c.compare(e1, e2)} must not throw a {@code ClassCastException}
* for any elements {@code e1} and {@code e2} in the array).
*
* This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.<p>
* <p>This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.
*
* The sorting algorithm is a modified mergesort (in which the merge is
* omitted if the highest element in the low sublist is less than the
* lowest element in the high sublist). This algorithm offers guaranteed
* n*log(n) performance.
* <p>Implementation note: This implementation is a stable, adaptive,
* iterative mergesort that requires far fewer than n lg(n) comparisons
* when the input array is partially sorted, while offering the
* performance of a traditional mergesort when the input array is
* randomly ordered. If the input array is nearly sorted, the
* implementation requires approximately n comparisons. Temporary
* storage requirements vary from a small constant for nearly sorted
* input arrays to n/2 object references for randomly ordered input
* arrays.
*
* <p>The implementation takes equal advantage of ascending and
* descending order in its input array, and can take advantage of
* ascending and descending order in different parts of the the same
* input array. It is well-suited to merging two or more sorted arrays:
* simply concatenate the arrays and sort the resulting array.
*
* <p>The implementation was adapted from Tim Peters's list sort for Python
* (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
* TimSort</a>). It uses techiques from Peter McIlroy's "Optimistic
* Sorting and Information Theoretic Complexity", in Proceedings of the
* Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
* January 1993.
*
* @param a the array to be sorted
* @param c the comparator to determine the order of the array. A
* <tt>null</tt> value indicates that the elements'
* {@code null} value indicates that the elements'
* {@linkplain Comparable natural ordering} should be used.
* @throws ClassCastException if the array contains elements that are
* not <i>mutually comparable</i> using the specified comparator.
* @throws ClassCastException if the array contains elements that are
* not <i>mutually comparable</i> using the specified comparator
* @throws IllegalArgumentException (optional) if the comparator is
* found to violate the {@link Comparator} contract
*/
public static <T> void sort(T[] a, Comparator<? super T> c) {
if (LegacyMergeSort.userRequested)
legacyMergeSort(a, c);
else
TimSort.sort(a, c);
}
/** To be removed in a future release. */
private static <T> void legacyMergeSort(T[] a, Comparator<? super T> c) {
T[] aux = a.clone();
if (c==null)
mergeSort(aux, a, 0, a.length, 0);
@ -1226,36 +1359,65 @@ public class Arrays {
/**
* Sorts the specified range of the specified array of objects according
* to the order induced by the specified comparator. The range to be
* sorted extends from index <tt>fromIndex</tt>, inclusive, to index
* <tt>toIndex</tt>, exclusive. (If <tt>fromIndex==toIndex</tt>, the
* sorted extends from index {@code fromIndex}, inclusive, to index
* {@code toIndex}, exclusive. (If {@code fromIndex==toIndex}, the
* range to be sorted is empty.) All elements in the range must be
* <i>mutually comparable</i> by the specified comparator (that is,
* <tt>c.compare(e1, e2)</tt> must not throw a <tt>ClassCastException</tt>
* for any elements <tt>e1</tt> and <tt>e2</tt> in the range).<p>
* {@code c.compare(e1, e2)} must not throw a {@code ClassCastException}
* for any elements {@code e1} and {@code e2} in the range).
*
* This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.<p>
* <p>This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.
*
* The sorting algorithm is a modified mergesort (in which the merge is
* omitted if the highest element in the low sublist is less than the
* lowest element in the high sublist). This algorithm offers guaranteed
* n*log(n) performance.
* <p>Implementation note: This implementation is a stable, adaptive,
* iterative mergesort that requires far fewer than n lg(n) comparisons
* when the input array is partially sorted, while offering the
* performance of a traditional mergesort when the input array is
* randomly ordered. If the input array is nearly sorted, the
* implementation requires approximately n comparisons. Temporary
* storage requirements vary from a small constant for nearly sorted
* input arrays to n/2 object references for randomly ordered input
* arrays.
*
* <p>The implementation takes equal advantage of ascending and
* descending order in its input array, and can take advantage of
* ascending and descending order in different parts of the the same
* input array. It is well-suited to merging two or more sorted arrays:
* simply concatenate the arrays and sort the resulting array.
*
* <p>The implementation was adapted from Tim Peters's list sort for Python
* (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
* TimSort</a>). It uses techiques from Peter McIlroy's "Optimistic
* Sorting and Information Theoretic Complexity", in Proceedings of the
* Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
* January 1993.
*
* @param a the array to be sorted
* @param fromIndex the index of the first element (inclusive) to be
* sorted
* @param toIndex the index of the last element (exclusive) to be sorted
* @param c the comparator to determine the order of the array. A
* <tt>null</tt> value indicates that the elements'
* {@code null} value indicates that the elements'
* {@linkplain Comparable natural ordering} should be used.
* @throws ClassCastException if the array contains elements that are not
* <i>mutually comparable</i> using the specified comparator.
* @throws IllegalArgumentException if <tt>fromIndex &gt; toIndex</tt>
* @throws ArrayIndexOutOfBoundsException if <tt>fromIndex &lt; 0</tt> or
* <tt>toIndex &gt; a.length</tt>
* @throws IllegalArgumentException if {@code fromIndex > toIndex} or
* (optional) if the comparator is found to violate the
* {@link Comparator} contract
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0} or
* {@code toIndex > a.length}
*/
public static <T> void sort(T[] a, int fromIndex, int toIndex,
Comparator<? super T> c) {
if (LegacyMergeSort.userRequested)
legacyMergeSort(a, fromIndex, toIndex, c);
else
TimSort.sort(a, fromIndex, toIndex, c);
}
/** To be removed in a future release. */
private static <T> void legacyMergeSort(T[] a, int fromIndex, int toIndex,
Comparator<? super T> c) {
rangeCheck(a.length, fromIndex, toIndex);
T[] aux = copyOfRange(a, fromIndex, toIndex);
if (c==null)
@ -1270,6 +1432,7 @@ public class Arrays {
* low is the index in dest to start sorting
* high is the end index in dest to end sorting
* off is the offset into src corresponding to low in dest
* To be removed in a future release.
*/
private static void mergeSort(Object[] src,
Object[] dest,

97
jdk/src/share/classes/java/util/Collections.java
View File

@ -100,23 +100,42 @@ public class Collections {
/**
* Sorts the specified list into ascending order, according to the
* <i>natural ordering</i> of its elements. All elements in the list must
* implement the <tt>Comparable</tt> interface. Furthermore, all elements
* in the list must be <i>mutually comparable</i> (that is,
* <tt>e1.compareTo(e2)</tt> must not throw a <tt>ClassCastException</tt>
* for any elements <tt>e1</tt> and <tt>e2</tt> in the list).<p>
* {@linkplain Comparable natural ordering} of its elements.
* All elements in the list must implement the {@link Comparable}
* interface. Furthermore, all elements in the list must be
* <i>mutually comparable</i> (that is, {@code e1.compareTo(e2)}
* must not throw a {@code ClassCastException} for any elements
* {@code e1} and {@code e2} in the list).
*
* This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.<p>
* <p>This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.
*
* The specified list must be modifiable, but need not be resizable.<p>
* <p>The specified list must be modifiable, but need not be resizable.
*
* The sorting algorithm is a modified mergesort (in which the merge is
* omitted if the highest element in the low sublist is less than the
* lowest element in the high sublist). This algorithm offers guaranteed
* n log(n) performance.
* <p>Implementation note: This implementation is a stable, adaptive,
* iterative mergesort that requires far fewer than n lg(n) comparisons
* when the input array is partially sorted, while offering the
* performance of a traditional mergesort when the input array is
* randomly ordered. If the input array is nearly sorted, the
* implementation requires approximately n comparisons. Temporary
* storage requirements vary from a small constant for nearly sorted
* input arrays to n/2 object references for randomly ordered input
* arrays.
*
* This implementation dumps the specified list into an array, sorts
* <p>The implementation takes equal advantage of ascending and
* descending order in its input array, and can take advantage of
* ascending and descending order in different parts of the the same
* input array. It is well-suited to merging two or more sorted arrays:
* simply concatenate the arrays and sort the resulting array.
*
* <p>The implementation was adapted from Tim Peters's list sort for Python
* (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
* TimSort</a>). It uses techiques from Peter McIlroy's "Optimistic
* Sorting and Information Theoretic Complexity", in Proceedings of the
* Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
* January 1993.
*
* <p>This implementation dumps the specified list into an array, sorts
* the array, and iterates over the list resetting each element
* from the corresponding position in the array. This avoids the
* n<sup>2</sup> log(n) performance that would result from attempting
@ -126,8 +145,10 @@ public class Collections {
* @throws ClassCastException if the list contains elements that are not
* <i>mutually comparable</i> (for example, strings and integers).
* @throws UnsupportedOperationException if the specified list's
* list-iterator does not support the <tt>set</tt> operation.
* @see Comparable
* list-iterator does not support the {@code set} operation.
* @throws IllegalArgumentException (optional) if the implementation
* detects that the natural ordering of the list elements is
* found to violate the {@link Comparable} contract
*/
public static <T extends Comparable<? super T>> void sort(List<T> list) {
Object[] a = list.toArray();
@ -143,19 +164,38 @@ public class Collections {
* Sorts the specified list according to the order induced by the
* specified comparator. All elements in the list must be <i>mutually
* comparable</i> using the specified comparator (that is,
* <tt>c.compare(e1, e2)</tt> must not throw a <tt>ClassCastException</tt>
* for any elements <tt>e1</tt> and <tt>e2</tt> in the list).<p>
* {@code c.compare(e1, e2)} must not throw a {@code ClassCastException}
* for any elements {@code e1} and {@code e2} in the list).
*
* This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.<p>
* <p>This sort is guaranteed to be <i>stable</i>: equal elements will
* not be reordered as a result of the sort.
*
* The sorting algorithm is a modified mergesort (in which the merge is
* omitted if the highest element in the low sublist is less than the
* lowest element in the high sublist). This algorithm offers guaranteed
* n log(n) performance.
* <p>The specified list must be modifiable, but need not be resizable.
*
* The specified list must be modifiable, but need not be resizable.
* This implementation dumps the specified list into an array, sorts
* <p>Implementation note: This implementation is a stable, adaptive,
* iterative mergesort that requires far fewer than n lg(n) comparisons
* when the input array is partially sorted, while offering the
* performance of a traditional mergesort when the input array is
* randomly ordered. If the input array is nearly sorted, the
* implementation requires approximately n comparisons. Temporary
* storage requirements vary from a small constant for nearly sorted
* input arrays to n/2 object references for randomly ordered input
* arrays.
*
* <p>The implementation takes equal advantage of ascending and
* descending order in its input array, and can take advantage of
* ascending and descending order in different parts of the the same
* input array. It is well-suited to merging two or more sorted arrays:
* simply concatenate the arrays and sort the resulting array.
*
* <p>The implementation was adapted from Tim Peters's list sort for Python
* (<a href="http://svn.python.org/projects/python/trunk/Objects/listsort.txt">
* TimSort</a>). It uses techiques from Peter McIlroy's "Optimistic
* Sorting and Information Theoretic Complexity", in Proceedings of the
* Fourth Annual ACM-SIAM Symposium on Discrete Algorithms, pp 467-474,
* January 1993.
*
* <p>This implementation dumps the specified list into an array, sorts
* the array, and iterates over the list resetting each element
* from the corresponding position in the array. This avoids the
* n<sup>2</sup> log(n) performance that would result from attempting
@ -163,13 +203,14 @@ public class Collections {
*
* @param list the list to be sorted.
* @param c the comparator to determine the order of the list. A
* <tt>null</tt> value indicates that the elements' <i>natural
* {@code null} value indicates that the elements' <i>natural
* ordering</i> should be used.
* @throws ClassCastException if the list contains elements that are not
* <i>mutually comparable</i> using the specified comparator.
* @throws UnsupportedOperationException if the specified list's
* list-iterator does not support the <tt>set</tt> operation.
* @see Comparator
* list-iterator does not support the {@code set} operation.
* @throws IllegalArgumentException (optional) if the comparator is
* found to violate the {@link Comparator} contract
*/
public static <T> void sort(List<T> list, Comparator<? super T> c) {
Object[] a = list.toArray();

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@ -0,0 +1,895 @@
/*
* Copyright 2009 Google Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package java.util;
/**
* This is a near duplicate of {@link TimSort}, modified for use with
* arrays of objects that implement {@link Comparable}, instead of using
* explicit comparators.
*
* <p>If you are using an optimizing VM, you may find that ComparableTimSort
* offers no performance benefit over TimSort in conjunction with a
* comparator that simply returns {@code ((Comparable)first).compareTo(Second)}.
* If this is the case, you are better off deleting ComparableTimSort to
* eliminate the code duplication. (See Arrays.java for details.)
*
* @author Josh Bloch
*/
class ComparableTimSort {
/**
* This is the minimum sized sequence that will be merged. Shorter
* sequences will be lengthened by calling binarySort. If the entire
* array is less than this length, no merges will be performed.
*
* This constant should be a power of two. It was 64 in Tim Peter's C
* implementation, but 32 was empirically determined to work better in
* this implementation. In the unlikely event that you set this constant
* to be a number that's not a power of two, you'll need to change the
* {@link #minRunLength} computation.
*
* If you decrease this constant, you must change the stackLen
* computation in the TimSort constructor, or you risk an
* ArrayOutOfBounds exception. See listsort.txt for a discussion
* of the minimum stack length required as a function of the length
* of the array being sorted and the minimum merge sequence length.
*/
private static final int MIN_MERGE = 32;
/**
* The array being sorted.
*/
private final Object[] a;
/**
* When we get into galloping mode, we stay there until both runs win less
* often than MIN_GALLOP consecutive times.
*/
private static final int MIN_GALLOP = 7;
/**
* This controls when we get *into* galloping mode. It is initialized
* to MIN_GALLOP. The mergeLo and mergeHi methods nudge it higher for
* random data, and lower for highly structured data.
*/
private int minGallop = MIN_GALLOP;
/**
* Maximum initial size of tmp array, which is used for merging. The array
* can grow to accommodate demand.
*
* Unlike Tim's original C version, we do not allocate this much storage
* when sorting smaller arrays. This change was required for performance.
*/
private static final int INITIAL_TMP_STORAGE_LENGTH = 256;
/**
* Temp storage for merges.
*/
private Object[] tmp;
/**
* A stack of pending runs yet to be merged. Run i starts at
* address base[i] and extends for len[i] elements. It's always
* true (so long as the indices are in bounds) that:
*
* runBase[i] + runLen[i] == runBase[i + 1]
*
* so we could cut the storage for this, but it's a minor amount,
* and keeping all the info explicit simplifies the code.
*/
private int stackSize = 0; // Number of pending runs on stack
private final int[] runBase;
private final int[] runLen;
/**
* Creates a TimSort instance to maintain the state of an ongoing sort.
*
* @param a the array to be sorted
*/
private ComparableTimSort(Object[] a) {
this.a = a;
// Allocate temp storage (which may be increased later if necessary)
int len = a.length;
@SuppressWarnings({"unchecked", "UnnecessaryLocalVariable"})
Object[] newArray = new Object[len < 2 * INITIAL_TMP_STORAGE_LENGTH ?
len >>> 1 : INITIAL_TMP_STORAGE_LENGTH];
tmp = newArray;
/*
* Allocate runs-to-be-merged stack (which cannot be expanded). The
* stack length requirements are described in listsort.txt. The C
* version always uses the same stack length (85), but this was
* measured to be too expensive when sorting "mid-sized" arrays (e.g.,
* 100 elements) in Java. Therefore, we use smaller (but sufficiently
* large) stack lengths for smaller arrays. The "magic numbers" in the
* computation below must be changed if MIN_MERGE is decreased. See
* the MIN_MERGE declaration above for more information.
*/
int stackLen = (len < 120 ? 5 :
len < 1542 ? 10 :
len < 119151 ? 19 : 40);
runBase = new int[stackLen];
runLen = new int[stackLen];
}
/*
* The next two methods (which are package private and static) constitute
* the entire API of this class. Each of these methods obeys the contract
* of the public method with the same signature in java.util.Arrays.
*/
static void sort(Object[] a) {
sort(a, 0, a.length);
}
static void sort(Object[] a, int lo, int hi) {
rangeCheck(a.length, lo, hi);
int nRemaining = hi - lo;
if (nRemaining < 2)
return; // Arrays of size 0 and 1 are always sorted
// If array is small, do a "mini-TimSort" with no merges
if (nRemaining < MIN_MERGE) {
int initRunLen = countRunAndMakeAscending(a, lo, hi);
binarySort(a, lo, hi, lo + initRunLen);
return;
}
/**
* March over the array once, left to right, finding natural runs,
* extending short natural runs to minRun elements, and merging runs
* to maintain stack invariant.
*/
ComparableTimSort ts = new ComparableTimSort(a);
int minRun = minRunLength(nRemaining);
do {
// Identify next run
int runLen = countRunAndMakeAscending(a, lo, hi);
// If run is short, extend to min(minRun, nRemaining)
if (runLen < minRun) {
int force = nRemaining <= minRun ? nRemaining : minRun;
binarySort(a, lo, lo + force, lo + runLen);
runLen = force;
}
// Push run onto pending-run stack, and maybe merge
ts.pushRun(lo, runLen);
ts.mergeCollapse();
// Advance to find next run
lo += runLen;
nRemaining -= runLen;
} while (nRemaining != 0);
// Merge all remaining runs to complete sort
assert lo == hi;
ts.mergeForceCollapse();
assert ts.stackSize == 1;
}
/**
* Sorts the specified portion of the specified array using a binary
* insertion sort. This is the best method for sorting small numbers
* of elements. It requires O(n log n) compares, but O(n^2) data
* movement (worst case).
*
* If the initial part of the specified range is already sorted,
* this method can take advantage of it: the method assumes that the
* elements from index {@code lo}, inclusive, to {@code start},
* exclusive are already sorted.
*
* @param a the array in which a range is to be sorted
* @param lo the index of the first element in the range to be sorted
* @param hi the index after the last element in the range to be sorted
* @param start the index of the first element in the range that is
* not already known to be sorted (@code lo <= start <= hi}
*/
@SuppressWarnings("fallthrough")
private static void binarySort(Object[] a, int lo, int hi, int start) {
assert lo <= start && start <= hi;
if (start == lo)
start++;
for ( ; start < hi; start++) {
@SuppressWarnings("unchecked")
Comparable<Object> pivot = (Comparable) a[start];
// Set left (and right) to the index where a[start] (pivot) belongs
int left = lo;
int right = start;
assert left <= right;
/*
* Invariants:
* pivot >= all in [lo, left).
* pivot < all in [right, start).
*/
while (left < right) {
int mid = (left + right) >>> 1;
if (pivot.compareTo(a[mid]) < 0)
right = mid;
else
left = mid + 1;
}
assert left == right;
/*
* The invariants still hold: pivot >= all in [lo, left) and
* pivot < all in [left, start), so pivot belongs at left. Note
* that if there are elements equal to pivot, left points to the
* first slot after them -- that's why this sort is stable.
* Slide elements over to make room to make room for pivot.
*/
int n = start - left; // The number of elements to move
// Switch is just an optimization for arraycopy in default case
switch(n) {
case 2: a[left + 2] = a[left + 1];
case 1: a[left + 1] = a[left];
break;
default: System.arraycopy(a, left, a, left + 1, n);
}
a[left] = pivot;
}
}
/**
* Returns the length of the run beginning at the specified position in
* the specified array and reverses the run if it is descending (ensuring
* that the run will always be ascending when the method returns).
*
* A run is the longest ascending sequence with:
*
* a[lo] <= a[lo + 1] <= a[lo + 2] <= ...
*
* or the longest descending sequence with:
*
* a[lo] > a[lo + 1] > a[lo + 2] > ...
*
* For its intended use in a stable mergesort, the strictness of the
* definition of "descending" is needed so that the call can safely
* reverse a descending sequence without violating stability.
*
* @param a the array in which a run is to be counted and possibly reversed
* @param lo index of the first element in the run
* @param hi index after the last element that may be contained in the run.
It is required that @code{lo < hi}.
* @return the length of the run beginning at the specified position in
* the specified array
*/
@SuppressWarnings("unchecked")
private static int countRunAndMakeAscending(Object[] a, int lo, int hi) {
assert lo < hi;
int runHi = lo + 1;
if (runHi == hi)
return 1;
// Find end of run, and reverse range if descending
if (((Comparable) a[runHi++]).compareTo(a[lo]) < 0) { // Descending
while(runHi < hi && ((Comparable) a[runHi]).compareTo(a[runHi - 1]) < 0)
runHi++;
reverseRange(a, lo, runHi);
} else { // Ascending
while (runHi < hi && ((Comparable) a[runHi]).compareTo(a[runHi - 1]) >= 0)
runHi++;
}
return runHi - lo;
}
/**
* Reverse the specified range of the specified array.
*
* @param a the array in which a range is to be reversed
* @param lo the index of the first element in the range to be reversed
* @param hi the index after the last element in the range to be reversed
*/
private static void reverseRange(Object[] a, int lo, int hi) {
hi--;
while (lo < hi) {
Object t = a[lo];
a[lo++] = a[hi];
a[hi--] = t;
}
}
/**
* Returns the minimum acceptable run length for an array of the specified
* length. Natural runs shorter than this will be extended with
* {@link #binarySort}.
*
* Roughly speaking, the computation is:
*
* If n < MIN_MERGE, return n (it's too small to bother with fancy stuff).
* Else if n is an exact power of 2, return MIN_MERGE/2.
* Else return an int k, MIN_MERGE/2 <= k <= MIN_MERGE, such that n/k
* is close to, but strictly less than, an exact power of 2.
*
* For the rationale, see listsort.txt.
*
* @param n the length of the array to be sorted
* @return the length of the minimum run to be merged
*/
private static int minRunLength(int n) {
assert n >= 0;
int r = 0; // Becomes 1 if any 1 bits are shifted off
while (n >= MIN_MERGE) {
r |= (n & 1);
n >>= 1;
}
return n + r;
}
/**
* Pushes the specified run onto the pending-run stack.
*
* @param runBase index of the first element in the run
* @param runLen the number of elements in the run
*/
private void pushRun(int runBase, int runLen) {
this.runBase[stackSize] = runBase;
this.runLen[stackSize] = runLen;
stackSize++;
}
/**
* Examines the stack of runs waiting to be merged and merges adjacent runs
* until the stack invariants are reestablished:
*
* 1. runLen[i - 3] > runLen[i - 2] + runLen[i - 1]
* 2. runLen[i - 2] > runLen[i - 1]
*
* This method is called each time a new run is pushed onto the stack,
* so the invariants are guaranteed to hold for i < stackSize upon
* entry to the method.
*/
private void mergeCollapse() {
while (stackSize > 1) {
int n = stackSize - 2;
if (n > 0 && runLen[n-1] <= runLen[n] + runLen[n+1]) {
if (runLen[n - 1] < runLen[n + 1])
n--;
mergeAt(n);
} else if (runLen[n] <= runLen[n + 1]) {
mergeAt(n);
} else {
break; // Invariant is established
}
}
}
/**
* Merges all runs on the stack until only one remains. This method is
* called once, to complete the sort.
*/
private void mergeForceCollapse() {
while (stackSize > 1) {
int n = stackSize - 2;
if (n > 0 && runLen[n - 1] < runLen[n + 1])
n--;
mergeAt(n);
}
}
/**
* Merges the two runs at stack indices i and i+1. Run i must be
* the penultimate or antepenultimate run on the stack. In other words,
* i must be equal to stackSize-2 or stackSize-3.
*
* @param i stack index of the first of the two runs to merge
*/
@SuppressWarnings("unchecked")
private void mergeAt(int i) {
assert stackSize >= 2;
assert i >= 0;
assert i == stackSize - 2 || i == stackSize - 3;
int base1 = runBase[i];
int len1 = runLen[i];
int base2 = runBase[i + 1];
int len2 = runLen[i + 1];
assert len1 > 0 && len2 > 0;
assert base1 + len1 == base2;
/*
* Record the length of the combined runs; if i is the 3rd-last
* run now, also slide over the last run (which isn't involved
* in this merge). The current run (i+1) goes away in any case.
*/
runLen[i] = len1 + len2;
if (i == stackSize - 3) {
runBase[i + 1] = runBase[i + 2];
runLen[i + 1] = runLen[i + 2];
}
stackSize--;
/*
* Find where the first element of run2 goes in run1. Prior elements
* in run1 can be ignored (because they're already in place).
*/
int k = gallopRight((Comparable<Object>) a[base2], a, base1, len1, 0);
assert k >= 0;
base1 += k;
len1 -= k;
if (len1 == 0)
return;
/*
* Find where the last element of run1 goes in run2. Subsequent elements
* in run2 can be ignored (because they're already in place).
*/
len2 = gallopLeft((Comparable<Object>) a[base1 + len1 - 1], a,
base2, len2, len2 - 1);
assert len2 >= 0;
if (len2 == 0)
return;
// Merge remaining runs, using tmp array with min(len1, len2) elements
if (len1 <= len2)
mergeLo(base1, len1, base2, len2);
else
mergeHi(base1, len1, base2, len2);
}
/**
* Locates the position at which to insert the specified key into the
* specified sorted range; if the range contains an element equal to key,
* returns the index of the leftmost equal element.
*
* @param key the key whose insertion point to search for
* @param a the array in which to search
* @param base the index of the first element in the range
* @param len the length of the range; must be > 0
* @param hint the index at which to begin the search, 0 <= hint < n.
* The closer hint is to the result, the faster this method will run.
* @return the int k, 0 <= k <= n such that a[b + k - 1] < key <= a[b + k],
* pretending that a[b - 1] is minus infinity and a[b + n] is infinity.
* In other words, key belongs at index b + k; or in other words,
* the first k elements of a should precede key, and the last n - k
* should follow it.
*/
private static int gallopLeft(Comparable<Object> key, Object[] a,
int base, int len, int hint) {
assert len > 0 && hint >= 0 && hint < len;
int lastOfs = 0;
int ofs = 1;
if (key.compareTo(a[base + hint]) > 0) {
// Gallop right until a[base+hint+lastOfs] < key <= a[base+hint+ofs]
int maxOfs = len - hint;
while (ofs < maxOfs && key.compareTo(a[base + hint + ofs]) > 0) {
lastOfs = ofs;
ofs = (ofs << 1) + 1;
if (ofs <= 0) // int overflow
ofs = maxOfs;
}
if (ofs > maxOfs)
ofs = maxOfs;
// Make offsets relative to base
lastOfs += hint;
ofs += hint;
} else { // key <= a[base + hint]
// Gallop left until a[base+hint-ofs] < key <= a[base+hint-lastOfs]
final int maxOfs = hint + 1;
while (ofs < maxOfs && key.compareTo(a[base + hint - ofs]) <= 0) {
lastOfs = ofs;
ofs = (ofs << 1) + 1;
if (ofs <= 0) // int overflow
ofs = maxOfs;
}
if (ofs > maxOfs)
ofs = maxOfs;
// Make offsets relative to base
int tmp = lastOfs;
lastOfs = hint - ofs;
ofs = hint - tmp;
}
assert -1 <= lastOfs && lastOfs < ofs && ofs <= len;
/*
* Now a[base+lastOfs] < key <= a[base+ofs], so key belongs somewhere
* to the right of lastOfs but no farther right than ofs. Do a binary
* search, with invariant a[base + lastOfs - 1] < key <= a[base + ofs].
*/
lastOfs++;
while (lastOfs < ofs) {
int m = lastOfs + ((ofs - lastOfs) >>> 1);
if (key.compareTo(a[base + m]) > 0)
lastOfs = m + 1; // a[base + m] < key
else
ofs = m; // key <= a[base + m]
}
assert lastOfs == ofs; // so a[base + ofs - 1] < key <= a[base + ofs]
return ofs;
}
/**
* Like gallopLeft, except that if the range contains an element equal to
* key, gallopRight returns the index after the rightmost equal element.
*
* @param key the key whose insertion point to search for
* @param a the array in which to search
* @param base the index of the first element in the range
* @param len the length of the range; must be > 0
* @param hint the index at which to begin the search, 0 <= hint < n.
* The closer hint is to the result, the faster this method will run.
* @return the int k, 0 <= k <= n such that a[b + k - 1] <= key < a[b + k]
*/
private static int gallopRight(Comparable<Object> key, Object[] a,
int base, int len, int hint) {
assert len > 0 && hint >= 0 && hint < len;
int ofs = 1;
int lastOfs = 0;
if (key.compareTo(a[base + hint]) < 0) {
// Gallop left until a[b+hint - ofs] <= key < a[b+hint - lastOfs]
int maxOfs = hint + 1;
while (ofs < maxOfs && key.compareTo(a[base + hint - ofs]) < 0) {
lastOfs = ofs;
ofs = (ofs << 1) + 1;
if (ofs <= 0) // int overflow
ofs = maxOfs;
}
if (ofs > maxOfs)
ofs = maxOfs;
// Make offsets relative to b
int tmp = lastOfs;
lastOfs = hint - ofs;
ofs = hint - tmp;
} else { // a[b + hint] <= key
// Gallop right until a[b+hint + lastOfs] <= key < a[b+hint + ofs]
int maxOfs = len - hint;
while (ofs < maxOfs && key.compareTo(a[base + hint + ofs]) >= 0) {
lastOfs = ofs;
ofs = (ofs << 1) + 1;
if (ofs <= 0) // int overflow
ofs = maxOfs;
}
if (ofs > maxOfs)
ofs = maxOfs;
// Make offsets relative to b
lastOfs += hint;
ofs += hint;
}
assert -1 <= lastOfs && lastOfs < ofs && ofs <= len;
/*
* Now a[b + lastOfs] <= key < a[b + ofs], so key belongs somewhere to
* the right of lastOfs but no farther right than ofs. Do a binary
* search, with invariant a[b + lastOfs - 1] <= key < a[b + ofs].
*/
lastOfs++;
while (lastOfs < ofs) {
int m = lastOfs + ((ofs - lastOfs) >>> 1);
if (key.compareTo(a[base + m]) < 0)
ofs = m; // key < a[b + m]
else
lastOfs = m + 1; // a[b + m] <= key
}
assert lastOfs == ofs; // so a[b + ofs - 1] <= key < a[b + ofs]
return ofs;
}
/**
* Merges two adjacent runs in place, in a stable fashion. The first
* element of the first run must be greater than the first element of the
* second run (a[base1] > a[base2]), and the last element of the first run
* (a[base1 + len1-1]) must be greater than all elements of the second run.
*
* For performance, this method should be called only when len1 <= len2;
* its twin, mergeHi should be called if len1 >= len2. (Either method
* may be called if len1 == len2.)
*
* @param base1 index of first element in first run to be merged
* @param len1 length of first run to be merged (must be > 0)
* @param base2 index of first element in second run to be merged
* (must be aBase + aLen)
* @param len2 length of second run to be merged (must be > 0)
*/
@SuppressWarnings("unchecked")
private void mergeLo(int base1, int len1, int base2, int len2) {
assert len1 > 0 && len2 > 0 && base1 + len1 == base2;
// Copy first run into temp array
Object[] a = this.a; // For performance
Object[] tmp = ensureCapacity(len1);
System.arraycopy(a, base1, tmp, 0, len1);
int cursor1 = 0; // Indexes into tmp array
int cursor2 = base2; // Indexes int a
int dest = base1; // Indexes int a
// Move first element of second run and deal with degenerate cases
a[dest++] = a[cursor2++];
if (--len2 == 0) {
System.arraycopy(tmp, cursor1, a, dest, len1);
return;
}
if (len1 == 1) {
System.arraycopy(a, cursor2, a, dest, len2);
a[dest + len2] = tmp[cursor1]; // Last elt of run 1 to end of merge
return;
}
int minGallop = this.minGallop; // Use local variable for performance
outer:
while (true) {
int count1 = 0; // Number of times in a row that first run won
int count2 = 0; // Number of times in a row that second run won
/*
* Do the straightforward thing until (if ever) one run starts
* winning consistently.
*/
do {
assert len1 > 1 && len2 > 0;
if (((Comparable) a[cursor2]).compareTo(tmp[cursor1]) < 0) {
a[dest++] = a[cursor2++];
count2++;
count1 = 0;
if (--len2 == 0)
break outer;
} else {
a[dest++] = tmp[cursor1++];
count1++;
count2 = 0;
if (--len1 == 1)
break outer;
}
} while ((count1 | count2) < minGallop);
/*
* One run is winning so consistently that galloping may be a
* huge win. So try that, and continue galloping until (if ever)
* neither run appears to be winning consistently anymore.
*/
do {
assert len1 > 1 && len2 > 0;
count1 = gallopRight((Comparable) a[cursor2], tmp, cursor1, len1, 0);
if (count1 != 0) {
System.arraycopy(tmp, cursor1, a, dest, count1);
dest += count1;
cursor1 += count1;
len1 -= count1;
if (len1 <= 1) // len1 == 1 || len1 == 0
break outer;
}
a[dest++] = a[cursor2++];
if (--len2 == 0)
break outer;
count2 = gallopLeft((Comparable) tmp[cursor1], a, cursor2, len2, 0);
if (count2 != 0) {
System.arraycopy(a, cursor2, a, dest, count2);
dest += count2;
cursor2 += count2;
len2 -= count2;
if (len2 == 0)
break outer;
}
a[dest++] = tmp[cursor1++];
if (--len1 == 1)
break outer;
minGallop--;
} while (count1 >= MIN_GALLOP | count2 >= MIN_GALLOP);
if (minGallop < 0)
minGallop = 0;
minGallop += 2; // Penalize for leaving gallop mode
} // End of "outer" loop
this.minGallop = minGallop < 1 ? 1 : minGallop; // Write back to field
if (len1 == 1) {
assert len2 > 0;
System.arraycopy(a, cursor2, a, dest, len2);
a[dest + len2] = tmp[cursor1]; // Last elt of run 1 to end of merge
} else if (len1 == 0) {
throw new IllegalArgumentException(
"Comparison method violates its general contract!");
} else {
assert len2 == 0;
assert len1 > 1;
System.arraycopy(tmp, cursor1, a, dest, len1);
}
}
/**
* Like mergeLo, except that this method should be called only if
* len1 >= len2; mergeLo should be called if len1 <= len2. (Either method
* may be called if len1 == len2.)
*
* @param base1 index of first element in first run to be merged
* @param len1 length of first run to be merged (must be > 0)
* @param base2 index of first element in second run to be merged
* (must be aBase + aLen)
* @param len2 length of second run to be merged (must be > 0)
*/
@SuppressWarnings("unchecked")
private void mergeHi(int base1, int len1, int base2, int len2) {
assert len1 > 0 && len2 > 0 && base1 + len1 == base2;
// Copy second run into temp array
Object[] a = this.a; // For performance
Object[] tmp = ensureCapacity(len2);
System.arraycopy(a, base2, tmp, 0, len2);
int cursor1 = base1 + len1 - 1; // Indexes into a
int cursor2 = len2 - 1; // Indexes into tmp array
int dest = base2 + len2 - 1; // Indexes into a
// Move last element of first run and deal with degenerate cases
a[dest--] = a[cursor1--];
if (--len1 == 0) {
System.arraycopy(tmp, 0, a, dest - (len2 - 1), len2);
return;
}
if (len2 == 1) {
dest -= len1;
cursor1 -= len1;
System.arraycopy(a, cursor1 + 1, a, dest + 1, len1);
a[dest] = tmp[cursor2];
return;
}
int minGallop = this.minGallop; // Use local variable for performance
outer:
while (true) {
int count1 = 0; // Number of times in a row that first run won
int count2 = 0; // Number of times in a row that second run won
/*
* Do the straightforward thing until (if ever) one run
* appears to win consistently.
*/
do {
assert len1 > 0 && len2 > 1;
if (((Comparable) tmp[cursor2]).compareTo(a[cursor1]) < 0) {
a[dest--] = a[cursor1--];
count1++;
count2 = 0;
if (--len1 == 0)
break outer;
} else {
a[dest--] = tmp[cursor2--];
count2++;
count1 = 0;
if (--len2 == 1)
break outer;
}
} while ((count1 | count2) < minGallop);
/*
* One run is winning so consistently that galloping may be a
* huge win. So try that, and continue galloping until (if ever)
* neither run appears to be winning consistently anymore.
*/
do {
assert len1 > 0 && len2 > 1;
count1 = len1 - gallopRight((Comparable) tmp[cursor2], a, base1, len1, len1 - 1);
if (count1 != 0) {
dest -= count1;
cursor1 -= count1;
len1 -= count1;
System.arraycopy(a, cursor1 + 1, a, dest + 1, count1);
if (len1 == 0)
break outer;
}
a[dest--] = tmp[cursor2--];
if (--len2 == 1)
break outer;
count2 = len2 - gallopLeft((Comparable) a[cursor1], tmp, 0, len2, len2 - 1);
if (count2 != 0) {
dest -= count2;
cursor2 -= count2;
len2 -= count2;
System.arraycopy(tmp, cursor2 + 1, a, dest + 1, count2);
if (len2 <= 1)
break outer; // len2 == 1 || len2 == 0
}
a[dest--] = a[cursor1--];
if (--len1 == 0)
break outer;
minGallop--;
} while (count1 >= MIN_GALLOP | count2 >= MIN_GALLOP);
if (minGallop < 0)
minGallop = 0;
minGallop += 2; // Penalize for leaving gallop mode
} // End of "outer" loop
this.minGallop = minGallop < 1 ? 1 : minGallop; // Write back to field
if (len2 == 1) {
assert len1 > 0;
dest -= len1;
cursor1 -= len1;
System.arraycopy(a, cursor1 + 1, a, dest + 1, len1);
a[dest] = tmp[cursor2]; // Move first elt of run2 to front of merge
} else if (len2 == 0) {
throw new IllegalArgumentException(
"Comparison method violates its general contract!");
} else {
assert len1 == 0;
assert len2 > 0;
System.arraycopy(tmp, 0, a, dest - (len2 - 1), len2);
}
}
/**
* Ensures that the external array tmp has at least the specified
* number of elements, increasing its size if necessary. The size
* increases exponentially to ensure amortized linear time complexity.
*
* @param minCapacity the minimum required capacity of the tmp array
* @return tmp, whether or not it grew
*/
private Object[] ensureCapacity(int minCapacity) {
if (tmp.length < minCapacity) {
// Compute smallest power of 2 > minCapacity
int newSize = minCapacity;
newSize |= newSize >> 1;
newSize |= newSize >> 2;
newSize |= newSize >> 4;
newSize |= newSize >> 8;
newSize |= newSize >> 16;
newSize++;
if (newSize < 0) // Not bloody likely!
newSize = minCapacity;
else
newSize = Math.min(newSize, a.length >>> 1);
@SuppressWarnings({"unchecked", "UnnecessaryLocalVariable"})
Object[] newArray = new Object[newSize];
tmp = newArray;
}
return tmp;
}
/**
* Checks that fromIndex and toIndex are in range, and throws an
* appropriate exception if they aren't.
*
* @param arrayLen the length of the array
* @param fromIndex the index of the first element of the range
* @param toIndex the index after the last element of the range
* @throws IllegalArgumentException if fromIndex > toIndex
* @throws ArrayIndexOutOfBoundsException if fromIndex < 0
* or toIndex > arrayLen
*/
private static void rangeCheck(int arrayLen, int fromIndex, int toIndex) {
if (fromIndex > toIndex)
throw new IllegalArgumentException("fromIndex(" + fromIndex +
") > toIndex(" + toIndex+")");
if (fromIndex < 0)
throw new ArrayIndexOutOfBoundsException(fromIndex);
if (toIndex > arrayLen)
throw new ArrayIndexOutOfBoundsException(toIndex);
}
}

11
jdk/src/share/classes/java/util/Formatter.java
View File

@ -2818,15 +2818,18 @@ public final class Formatter implements Closeable, Flushable {
}
private void printString(Object arg, Locale l) throws IOException {
if (arg == null) {
print("null");
} else if (arg instanceof Formattable) {
if (arg instanceof Formattable) {
Formatter fmt = formatter;
if (formatter.locale() != l)
fmt = new Formatter(formatter.out(), l);
((Formattable)arg).formatTo(fmt, f.valueOf(), width, precision);
} else {
print(arg.toString());
if (f.contains(Flags.ALTERNATE))
failMismatch(Flags.ALTERNATE, 's');
if (arg == null)
print("null");
else
print(arg.toString());
}
}

928
jdk/src/share/classes/java/util/TimSort.java Normal file
View File

@ -0,0 +1,928 @@
/*
* Copyright 2009 Google Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Sun designates this
* particular file as subject to the "Classpath" exception as provided
* by Sun in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
package java.util;
/**
* A stable, adaptive, iterative mergesort that requires far fewer than
* n lg(n) comparisons when running on partially sorted arrays, while
* offering performance comparable to a traditional mergesort when run
* on random arrays. Like all proper mergesorts, this sort is stable and
* runs O(n log n) time (worst case). In the worst case, this sort requires
* temporary storage space for n/2 object references; in the best case,
* it requires only a small constant amount of space.
*
* This implementation was adapted from Tim Peters's list sort for
* Python, which is described in detail here:
*
* http://svn.python.org/projects/python/trunk/Objects/listsort.txt
*
* Tim's C code may be found here:
*
* http://svn.python.org/projects/python/trunk/Objects/listobject.c
*
* The underlying techniques are described in this paper (and may have
* even earlier origins):
*
* "Optimistic Sorting and Information Theoretic Complexity"
* Peter McIlroy
* SODA (Fourth Annual ACM-SIAM Symposium on Discrete Algorithms),
* pp 467-474, Austin, Texas, 25-27 January 1993.
*
* While the API to this class consists solely of static methods, it is
* (privately) instantiable; a TimSort instance holds the state of an ongoing
* sort, assuming the input array is large enough to warrant the full-blown
* TimSort. Small arrays are sorted in place, using a binary insertion sort.
*
* @author Josh Bloch
*/
class TimSort<T> {
/**
* This is the minimum sized sequence that will be merged. Shorter
* sequences will be lengthened by calling binarySort. If the entire
* array is less than this length, no merges will be performed.
*
* This constant should be a power of two. It was 64 in Tim Peter's C
* implementation, but 32 was empirically determined to work better in
* this implementation. In the unlikely event that you set this constant
* to be a number that's not a power of two, you'll need to change the
* {@link #minRunLength} computation.
*
* If you decrease this constant, you must change the stackLen
* computation in the TimSort constructor, or you risk an
* ArrayOutOfBounds exception. See listsort.txt for a discussion
* of the minimum stack length required as a function of the length
* of the array being sorted and the minimum merge sequence length.
*/
private static final int MIN_MERGE = 32;
/**
* The array being sorted.
*/
private final T[] a;
/**
* The comparator for this sort.
*/
private final Comparator<? super T> c;
/**
* When we get into galloping mode, we stay there until both runs win less
* often than MIN_GALLOP consecutive times.
*/
private static final int MIN_GALLOP = 7;
/**
* This controls when we get *into* galloping mode. It is initialized
* to MIN_GALLOP. The mergeLo and mergeHi methods nudge it higher for
* random data, and lower for highly structured data.
*/
private int minGallop = MIN_GALLOP;
/**
* Maximum initial size of tmp array, which is used for merging. The array
* can grow to accommodate demand.
*
* Unlike Tim's original C version, we do not allocate this much storage
* when sorting smaller arrays. This change was required for performance.
*/
private static final int INITIAL_TMP_STORAGE_LENGTH = 256;
/**
* Temp storage for merges.
*/
private T[] tmp; // Actual runtime type will be Object[], regardless of T
/**
* A stack of pending runs yet to be merged. Run i starts at
* address base[i] and extends for len[i] elements. It's always
* true (so long as the indices are in bounds) that:
*
* runBase[i] + runLen[i] == runBase[i + 1]
*
* so we could cut the storage for this, but it's a minor amount,
* and keeping all the info explicit simplifies the code.
*/
private int stackSize = 0; // Number of pending runs on stack
private final int[] runBase;
private final int[] runLen;
/**
* Creates a TimSort instance to maintain the state of an ongoing sort.
*
* @param a the array to be sorted
* @param c the comparator to determine the order of the sort
*/
private TimSort(T[] a, Comparator<? super T> c) {
this.a = a;
this.c = c;
// Allocate temp storage (which may be increased later if necessary)
int len = a.length;
@SuppressWarnings({"unchecked", "UnnecessaryLocalVariable"})
T[] newArray = (T[]) new Object[len < 2 * INITIAL_TMP_STORAGE_LENGTH ?
len >>> 1 : INITIAL_TMP_STORAGE_LENGTH];
tmp = newArray;
/*
* Allocate runs-to-be-merged stack (which cannot be expanded). The
* stack length requirements are described in listsort.txt. The C
* version always uses the same stack length (85), but this was
* measured to be too expensive when sorting "mid-sized" arrays (e.g.,
* 100 elements) in Java. Therefore, we use smaller (but sufficiently
* large) stack lengths for smaller arrays. The "magic numbers" in the
* computation below must be changed if MIN_MERGE is decreased. See
* the MIN_MERGE declaration above for more information.
*/
int stackLen = (len < 120 ? 5 :
len < 1542 ? 10 :
len < 119151 ? 19 : 40);
runBase = new int[stackLen];
runLen = new int[stackLen];
}
/*
* The next two methods (which are package private and static) constitute
* the entire API of this class. Each of these methods obeys the contract
* of the public method with the same signature in java.util.Arrays.
*/
static <T> void sort(T[] a, Comparator<? super T> c) {
sort(a, 0, a.length, c);
}
static <T> void sort(T[] a, int lo, int hi, Comparator<? super T> c) {
if (c == null) {
Arrays.sort(a, lo, hi);
return;
}
rangeCheck(a.length, lo, hi);
int nRemaining = hi - lo;
if (nRemaining < 2)
return; // Arrays of size 0 and 1 are always sorted
// If array is small, do a "mini-TimSort" with no merges
if (nRemaining < MIN_MERGE) {
int initRunLen = countRunAndMakeAscending(a, lo, hi, c);
binarySort(a, lo, hi, lo + initRunLen, c);
return;
}
/**
* March over the array once, left to right, finding natural runs,
* extending short natural runs to minRun elements, and merging runs
* to maintain stack invariant.
*/
TimSort<T> ts = new TimSort<T>(a, c);
int minRun = minRunLength(nRemaining);
do {
// Identify next run
int runLen = countRunAndMakeAscending(a, lo, hi, c);
// If run is short, extend to min(minRun, nRemaining)
if (runLen < minRun) {
int force = nRemaining <= minRun ? nRemaining : minRun;
binarySort(a, lo, lo + force, lo + runLen, c);
runLen = force;
}
// Push run onto pending-run stack, and maybe merge
ts.pushRun(lo, runLen);
ts.mergeCollapse();
// Advance to find next run
lo += runLen;
nRemaining -= runLen;
} while (nRemaining != 0);
// Merge all remaining runs to complete sort
assert lo == hi;
ts.mergeForceCollapse();
assert ts.stackSize == 1;
}
/**
* Sorts the specified portion of the specified array using a binary
* insertion sort. This is the best method for sorting small numbers
* of elements. It requires O(n log n) compares, but O(n^2) data
* movement (worst case).
*
* If the initial part of the specified range is already sorted,
* this method can take advantage of it: the method assumes that the
* elements from index {@code lo}, inclusive, to {@code start},
* exclusive are already sorted.
*
* @param a the array in which a range is to be sorted
* @param lo the index of the first element in the range to be sorted
* @param hi the index after the last element in the range to be sorted
* @param start the index of the first element in the range that is
* not already known to be sorted (@code lo <= start <= hi}
* @param c comparator to used for the sort
*/
@SuppressWarnings("fallthrough")
private static <T> void binarySort(T[] a, int lo, int hi, int start,
Comparator<? super T> c) {
assert lo <= start && start <= hi;
if (start == lo)
start++;
for ( ; start < hi; start++) {
T pivot = a[start];
// Set left (and right) to the index where a[start] (pivot) belongs
int left = lo;
int right = start;
assert left <= right;
/*
* Invariants:
* pivot >= all in [lo, left).
* pivot < all in [right, start).
*/
while (left < right) {
int mid = (left + right) >>> 1;
if (c.compare(pivot, a[mid]) < 0)
right = mid;
else
left = mid + 1;
}
assert left == right;
/*
* The invariants still hold: pivot >= all in [lo, left) and
* pivot < all in [left, start), so pivot belongs at left. Note
* that if there are elements equal to pivot, left points to the
* first slot after them -- that's why this sort is stable.
* Slide elements over to make room to make room for pivot.
*/
int n = start - left; // The number of elements to move
// Switch is just an optimization for arraycopy in default case
switch(n) {
case 2: a[left + 2] = a[left + 1];
case 1: a[left + 1] = a[left];
break;
default: System.arraycopy(a, left, a, left + 1, n);
}
a[left] = pivot;
}
}
/**
* Returns the length of the run beginning at the specified position in
* the specified array and reverses the run if it is descending (ensuring
* that the run will always be ascending when the method returns).
*
* A run is the longest ascending sequence with:
*
* a[lo] <= a[lo + 1] <= a[lo + 2] <= ...
*
* or the longest descending sequence with:
*
* a[lo] > a[lo + 1] > a[lo + 2] > ...
*
* For its intended use in a stable mergesort, the strictness of the
* definition of "descending" is needed so that the call can safely
* reverse a descending sequence without violating stability.
*
* @param a the array in which a run is to be counted and possibly reversed
* @param lo index of the first element in the run
* @param hi index after the last element that may be contained in the run.
It is required that @code{lo < hi}.
* @param c the comparator to used for the sort
* @return the length of the run beginning at the specified position in
* the specified array
*/
private static <T> int countRunAndMakeAscending(T[] a, int lo, int hi,
Comparator<? super T> c) {
assert lo < hi;
int runHi = lo + 1;
if (runHi == hi)
return 1;
// Find end of run, and reverse range if descending
if (c.compare(a[runHi++], a[lo]) < 0) { // Descending
while(runHi < hi && c.compare(a[runHi], a[runHi - 1]) < 0)
runHi++;
reverseRange(a, lo, runHi);
} else { // Ascending
while (runHi < hi && c.compare(a[runHi], a[runHi - 1]) >= 0)
runHi++;
}
return runHi - lo;
}
/**
* Reverse the specified range of the specified array.
*
* @param a the array in which a range is to be reversed
* @param lo the index of the first element in the range to be reversed
* @param hi the index after the last element in the range to be reversed
*/
private static void reverseRange(Object[] a, int lo, int hi) {
hi--;
while (lo < hi) {
Object t = a[lo];
a[lo++] = a[hi];
a[hi--] = t;
}
}
/**
* Returns the minimum acceptable run length for an array of the specified
* length. Natural runs shorter than this will be extended with
* {@link #binarySort}.
*
* Roughly speaking, the computation is:
*
* If n < MIN_MERGE, return n (it's too small to bother with fancy stuff).
* Else if n is an exact power of 2, return MIN_MERGE/2.
* Else return an int k, MIN_MERGE/2 <= k <= MIN_MERGE, such that n/k
* is close to, but strictly less than, an exact power of 2.
*
* For the rationale, see listsort.txt.
*
* @param n the length of the array to be sorted
* @return the length of the minimum run to be merged
*/
private static int minRunLength(int n) {
assert n >= 0;
int r = 0; // Becomes 1 if any 1 bits are shifted off
while (n >= MIN_MERGE) {
r |= (n & 1);
n >>= 1;
}
return n + r;
}
/**
* Pushes the specified run onto the pending-run stack.
*
* @param runBase index of the first element in the run
* @param runLen the number of elements in the run
*/
private void pushRun(int runBase, int runLen) {
this.runBase[stackSize] = runBase;
this.runLen[stackSize] = runLen;
stackSize++;
}
/**
* Examines the stack of runs waiting to be merged and merges adjacent runs
* until the stack invariants are reestablished:
*
* 1. runLen[i - 3] > runLen[i - 2] + runLen[i - 1]
* 2. runLen[i - 2] > runLen[i - 1]
*
* This method is called each time a new run is pushed onto the stack,
* so the invariants are guaranteed to hold for i < stackSize upon
* entry to the method.
*/
private void mergeCollapse() {
while (stackSize > 1) {
int n = stackSize - 2;
if (n > 0 && runLen[n-1] <= runLen[n] + runLen[n+1]) {
if (runLen[n - 1] < runLen[n + 1])
n--;
mergeAt(n);
} else if (runLen[n] <= runLen[n + 1]) {
mergeAt(n);
} else {
break; // Invariant is established
}
}
}
/**
* Merges all runs on the stack until only one remains. This method is
* called once, to complete the sort.
*/
private void mergeForceCollapse() {
while (stackSize > 1) {
int n = stackSize - 2;
if (n > 0 && runLen[n - 1] < runLen[n + 1])
n--;
mergeAt(n);
}
}
/**
* Merges the two runs at stack indices i and i+1. Run i must be
* the penultimate or antepenultimate run on the stack. In other words,
* i must be equal to stackSize-2 or stackSize-3.
*
* @param i stack index of the first of the two runs to merge
*/
private void mergeAt(int i) {
assert stackSize >= 2;
assert i >= 0;
assert i == stackSize - 2 || i == stackSize - 3;
int base1 = runBase[i];
int len1 = runLen[i];
int base2 = runBase[i + 1];
int len2 = runLen[i + 1];
assert len1 > 0 && len2 > 0;
assert base1 + len1 == base2;
/*
* Record the length of the combined runs; if i is the 3rd-last
* run now, also slide over the last run (which isn't involved
* in this merge). The current run (i+1) goes away in any case.
*/
runLen[i] = len1 + len2;
if (i == stackSize - 3) {
runBase[i + 1] = runBase[i + 2];
runLen[i + 1] = runLen[i + 2];
}
stackSize--;
/*
* Find where the first element of run2 goes in run1. Prior elements
* in run1 can be ignored (because they're already in place).
*/
int k = gallopRight(a[base2], a, base1, len1, 0, c);
assert k >= 0;
base1 += k;
len1 -= k;
if (len1 == 0)
return;
/*
* Find where the last element of run1 goes in run2. Subsequent elements
* in run2 can be ignored (because they're already in place).
*/
len2 = gallopLeft(a[base1 + len1 - 1], a, base2, len2, len2 - 1, c);
assert len2 >= 0;
if (len2 == 0)
return;
// Merge remaining runs, using tmp array with min(len1, len2) elements
if (len1 <= len2)
mergeLo(base1, len1, base2, len2);
else
mergeHi(base1, len1, base2, len2);
}
/**
* Locates the position at which to insert the specified key into the
* specified sorted range; if the range contains an element equal to key,
* returns the index of the leftmost equal element.
*
* @param key the key whose insertion point to search for
* @param a the array in which to search
* @param base the index of the first element in the range
* @param len the length of the range; must be > 0
* @param hint the index at which to begin the search, 0 <= hint < n.
* The closer hint is to the result, the faster this method will run.
* @param c the comparator used to order the range, and to search
* @return the int k, 0 <= k <= n such that a[b + k - 1] < key <= a[b + k],
* pretending that a[b - 1] is minus infinity and a[b + n] is infinity.
* In other words, key belongs at index b + k; or in other words,
* the first k elements of a should precede key, and the last n - k
* should follow it.
*/
private static <T> int gallopLeft(T key, T[] a, int base, int len, int hint,
Comparator<? super T> c) {
assert len > 0 && hint >= 0 && hint < len;
int lastOfs = 0;
int ofs = 1;
if (c.compare(key, a[base + hint]) > 0) {
// Gallop right until a[base+hint+lastOfs] < key <= a[base+hint+ofs]
int maxOfs = len - hint;
while (ofs < maxOfs && c.compare(key, a[base + hint + ofs]) > 0) {
lastOfs = ofs;
ofs = (ofs << 1) + 1;
if (ofs <= 0) // int overflow
ofs = maxOfs;
}
if (ofs > maxOfs)
ofs = maxOfs;
// Make offsets relative to base
lastOfs += hint;
ofs += hint;
} else { // key <= a[base + hint]
// Gallop left until a[base+hint-ofs] < key <= a[base+hint-lastOfs]
final int maxOfs = hint + 1;
while (ofs < maxOfs && c.compare(key, a[base + hint - ofs]) <= 0) {
lastOfs = ofs;
ofs = (ofs << 1) + 1;
if (ofs <= 0) // int overflow
ofs = maxOfs;
}
if (ofs > maxOfs)
ofs = maxOfs;
// Make offsets relative to base
int tmp = lastOfs;
lastOfs = hint - ofs;
ofs = hint - tmp;
}
assert -1 <= lastOfs && lastOfs < ofs && ofs <= len;
/*
* Now a[base+lastOfs] < key <= a[base+ofs], so key belongs somewhere
* to the right of lastOfs but no farther right than ofs. Do a binary
* search, with invariant a[base + lastOfs - 1] < key <= a[base + ofs].
*/
lastOfs++;
while (lastOfs < ofs) {
int m = lastOfs + ((ofs - lastOfs) >>> 1);
if (c.compare(key, a[base + m]) > 0)
lastOfs = m + 1; // a[base + m] < key
else
ofs = m; // key <= a[base + m]
}
assert lastOfs == ofs; // so a[base + ofs - 1] < key <= a[base + ofs]
return ofs;
}
/**
* Like gallopLeft, except that if the range contains an element equal to
* key, gallopRight returns the index after the rightmost equal element.
*
* @param key the key whose insertion point to search for
* @param a the array in which to search
* @param base the index of the first element in the range
* @param len the length of the range; must be > 0
* @param hint the index at which to begin the search, 0 <= hint < n.
* The closer hint is to the result, the faster this method will run.
* @param c the comparator used to order the range, and to search
* @return the int k, 0 <= k <= n such that a[b + k - 1] <= key < a[b + k]
*/
private static <T> int gallopRight(T key, T[] a, int base, int len,
int hint, Comparator<? super T> c) {
assert len > 0 && hint >= 0 && hint < len;
int ofs = 1;
int lastOfs = 0;
if (c.compare(key, a[base + hint]) < 0) {
// Gallop left until a[b+hint - ofs] <= key < a[b+hint - lastOfs]
int maxOfs = hint + 1;
while (ofs < maxOfs && c.compare(key, a[base + hint - ofs]) < 0) {
lastOfs = ofs;
ofs = (ofs << 1) + 1;
if (ofs <= 0) // int overflow
ofs = maxOfs;
}
if (ofs > maxOfs)
ofs = maxOfs;
// Make offsets relative to b
int tmp = lastOfs;
lastOfs = hint - ofs;
ofs = hint - tmp;
} else { // a[b + hint] <= key
// Gallop right until a[b+hint + lastOfs] <= key < a[b+hint + ofs]
int maxOfs = len - hint;
while (ofs < maxOfs && c.compare(key, a[base + hint + ofs]) >= 0) {
lastOfs = ofs;
ofs = (ofs << 1) + 1;
if (ofs <= 0) // int overflow
ofs = maxOfs;
}
if (ofs > maxOfs)
ofs = maxOfs;
// Make offsets relative to b
lastOfs += hint;
ofs += hint;
}
assert -1 <= lastOfs && lastOfs < ofs && ofs <= len;
/*
* Now a[b + lastOfs] <= key < a[b + ofs], so key belongs somewhere to
* the right of lastOfs but no farther right than ofs. Do a binary
* search, with invariant a[b + lastOfs - 1] <= key < a[b + ofs].
*/
lastOfs++;
while (lastOfs < ofs) {
int m = lastOfs + ((ofs - lastOfs) >>> 1);
if (c.compare(key, a[base + m]) < 0)
ofs = m; // key < a[b + m]
else
lastOfs = m + 1; // a[b + m] <= key
}
assert lastOfs == ofs; // so a[b + ofs - 1] <= key < a[b + ofs]
return ofs;
}
/**
* Merges two adjacent runs in place, in a stable fashion. The first
* element of the first run must be greater than the first element of the
* second run (a[base1] > a[base2]), and the last element of the first run
* (a[base1 + len1-1]) must be greater than all elements of the second run.
*
* For performance, this method should be called only when len1 <= len2;
* its twin, mergeHi should be called if len1 >= len2. (Either method
* may be called if len1 == len2.)
*
* @param base1 index of first element in first run to be merged
* @param len1 length of first run to be merged (must be > 0)
* @param base2 index of first element in second run to be merged
* (must be aBase + aLen)
* @param len2 length of second run to be merged (must be > 0)
*/
private void mergeLo(int base1, int len1, int base2, int len2) {
assert len1 > 0 && len2 > 0 && base1 + len1 == base2;
// Copy first run into temp array
T[] a = this.a; // For performance
T[] tmp = ensureCapacity(len1);
System.arraycopy(a, base1, tmp, 0, len1);
int cursor1 = 0; // Indexes into tmp array
int cursor2 = base2; // Indexes int a
int dest = base1; // Indexes int a
// Move first element of second run and deal with degenerate cases
a[dest++] = a[cursor2++];
if (--len2 == 0) {
System.arraycopy(tmp, cursor1, a, dest, len1);
return;
}
if (len1 == 1) {
System.arraycopy(a, cursor2, a, dest, len2);
a[dest + len2] = tmp[cursor1]; // Last elt of run 1 to end of merge
return;
}
Comparator<? super T> c = this.c; // Use local variable for performance
int minGallop = this.minGallop; // " " " " "
outer:
while (true) {
int count1 = 0; // Number of times in a row that first run won
int count2 = 0; // Number of times in a row that second run won
/*
* Do the straightforward thing until (if ever) one run starts
* winning consistently.
*/
do {
assert len1 > 1 && len2 > 0;
if (c.compare(a[cursor2], tmp[cursor1]) < 0) {
a[dest++] = a[cursor2++];
count2++;
count1 = 0;
if (--len2 == 0)
break outer;
} else {
a[dest++] = tmp[cursor1++];
count1++;
count2 = 0;
if (--len1 == 1)
break outer;
}
} while ((count1 | count2) < minGallop);
/*
* One run is winning so consistently that galloping may be a
* huge win. So try that, and continue galloping until (if ever)
* neither run appears to be winning consistently anymore.
*/
do {
assert len1 > 1 && len2 > 0;
count1 = gallopRight(a[cursor2], tmp, cursor1, len1, 0, c);
if (count1 != 0) {
System.arraycopy(tmp, cursor1, a, dest, count1);
dest += count1;
cursor1 += count1;
len1 -= count1;
if (len1 <= 1) // len1 == 1 || len1 == 0
break outer;
}
a[dest++] = a[cursor2++];
if (--len2 == 0)
break outer;
count2 = gallopLeft(tmp[cursor1], a, cursor2, len2, 0, c);
if (count2 != 0) {
System.arraycopy(a, cursor2, a, dest, count2);
dest += count2;
cursor2 += count2;
len2 -= count2;
if (len2 == 0)
break outer;
}
a[dest++] = tmp[cursor1++];
if (--len1 == 1)
break outer;
minGallop--;
} while (count1 >= MIN_GALLOP | count2 >= MIN_GALLOP);
if (minGallop < 0)
minGallop = 0;
minGallop += 2; // Penalize for leaving gallop mode
} // End of "outer" loop
this.minGallop = minGallop < 1 ? 1 : minGallop; // Write back to field
if (len1 == 1) {
assert len2 > 0;
System.arraycopy(a, cursor2, a, dest, len2);
a[dest + len2] = tmp[cursor1]; // Last elt of run 1 to end of merge
} else if (len1 == 0) {
throw new IllegalArgumentException(
"Comparison method violates its general contract!");
} else {
assert len2 == 0;
assert len1 > 1;
System.arraycopy(tmp, cursor1, a, dest, len1);
}
}
/**
* Like mergeLo, except that this method should be called only if
* len1 >= len2; mergeLo should be called if len1 <= len2. (Either method
* may be called if len1 == len2.)
*
* @param base1 index of first element in first run to be merged
* @param len1 length of first run to be merged (must be > 0)
* @param base2 index of first element in second run to be merged
* (must be aBase + aLen)
* @param len2 length of second run to be merged (must be > 0)
*/
private void mergeHi(int base1, int len1, int base2, int len2) {
assert len1 > 0 && len2 > 0 && base1 + len1 == base2;
// Copy second run into temp array
T[] a = this.a; // For performance
T[] tmp = ensureCapacity(len2);
System.arraycopy(a, base2, tmp, 0, len2);
int cursor1 = base1 + len1 - 1; // Indexes into a
int cursor2 = len2 - 1; // Indexes into tmp array
int dest = base2 + len2 - 1; // Indexes into a
// Move last element of first run and deal with degenerate cases
a[dest--] = a[cursor1--];
if (--len1 == 0) {
System.arraycopy(tmp, 0, a, dest - (len2 - 1), len2);
return;
}
if (len2 == 1) {
dest -= len1;
cursor1 -= len1;
System.arraycopy(a, cursor1 + 1, a, dest + 1, len1);
a[dest] = tmp[cursor2];
return;
}
Comparator<? super T> c = this.c; // Use local variable for performance
int minGallop = this.minGallop; // " " " " "
outer:
while (true) {
int count1 = 0; // Number of times in a row that first run won
int count2 = 0; // Number of times in a row that second run won
/*
* Do the straightforward thing until (if ever) one run
* appears to win consistently.
*/
do {
assert len1 > 0 && len2 > 1;
if (c.compare(tmp[cursor2], a[cursor1]) < 0) {
a[dest--] = a[cursor1--];
count1++;
count2 = 0;
if (--len1 == 0)
break outer;
} else {
a[dest--] = tmp[cursor2--];
count2++;
count1 = 0;
if (--len2 == 1)
break outer;
}
} while ((count1 | count2) < minGallop);
/*
* One run is winning so consistently that galloping may be a
* huge win. So try that, and continue galloping until (if ever)
* neither run appears to be winning consistently anymore.
*/
do {
assert len1 > 0 && len2 > 1;
count1 = len1 - gallopRight(tmp[cursor2], a, base1, len1, len1 - 1, c);
if (count1 != 0) {
dest -= count1;
cursor1 -= count1;
len1 -= count1;
System.arraycopy(a, cursor1 + 1, a, dest + 1, count1);
if (len1 == 0)
break outer;
}
a[dest--] = tmp[cursor2--];
if (--len2 == 1)
break outer;
count2 = len2 - gallopLeft(a[cursor1], tmp, 0, len2, len2 - 1, c);
if (count2 != 0) {
dest -= count2;
cursor2 -= count2;
len2 -= count2;
System.arraycopy(tmp, cursor2 + 1, a, dest + 1, count2);
if (len2 <= 1) // len2 == 1 || len2 == 0
break outer;
}
a[dest--] = a[cursor1--];
if (--len1 == 0)
break outer;
minGallop--;
} while (count1 >= MIN_GALLOP | count2 >= MIN_GALLOP);
if (minGallop < 0)
minGallop = 0;
minGallop += 2; // Penalize for leaving gallop mode
} // End of "outer" loop
this.minGallop = minGallop < 1 ? 1 : minGallop; // Write back to field
if (len2 == 1) {
assert len1 > 0;
dest -= len1;
cursor1 -= len1;
System.arraycopy(a, cursor1 + 1, a, dest + 1, len1);
a[dest] = tmp[cursor2]; // Move first elt of run2 to front of merge
} else if (len2 == 0) {
throw new IllegalArgumentException(
"Comparison method violates its general contract!");
} else {
assert len1 == 0;
assert len2 > 0;
System.arraycopy(tmp, 0, a, dest - (len2 - 1), len2);
}
}
/**
* Ensures that the external array tmp has at least the specified
* number of elements, increasing its size if necessary. The size
* increases exponentially to ensure amortized linear time complexity.
*
* @param minCapacity the minimum required capacity of the tmp array
* @return tmp, whether or not it grew
*/
private T[] ensureCapacity(int minCapacity) {
if (tmp.length < minCapacity) {
// Compute smallest power of 2 > minCapacity
int newSize = minCapacity;
newSize |= newSize >> 1;
newSize |= newSize >> 2;
newSize |= newSize >> 4;
newSize |= newSize >> 8;
newSize |= newSize >> 16;
newSize++;
if (newSize < 0) // Not bloody likely!
newSize = minCapacity;
else
newSize = Math.min(newSize, a.length >>> 1);
@SuppressWarnings({"unchecked", "UnnecessaryLocalVariable"})
T[] newArray = (T[]) new Object[newSize];
tmp = newArray;
}
return tmp;
}
/**
* Checks that fromIndex and toIndex are in range, and throws an
* appropriate exception if they aren't.
*
* @param arrayLen the length of the array
* @param fromIndex the index of the first element of the range
* @param toIndex the index after the last element of the range
* @throws IllegalArgumentException if fromIndex > toIndex
* @throws ArrayIndexOutOfBoundsException if fromIndex < 0
* or toIndex > arrayLen
*/
private static void rangeCheck(int arrayLen, int fromIndex, int toIndex) {
if (fromIndex > toIndex)
throw new IllegalArgumentException("fromIndex(" + fromIndex +
") > toIndex(" + toIndex+")");
if (fromIndex < 0)
throw new ArrayIndexOutOfBoundsException(fromIndex);
if (toIndex > arrayLen)
throw new ArrayIndexOutOfBoundsException(toIndex);
}
}

451
jdk/src/share/classes/java/util/concurrent/ConcurrentLinkedQueue.java
View File

@ -34,9 +34,13 @@
*/
package java.util.concurrent;
import java.util.*;
import java.util.concurrent.atomic.*;
import java.util.AbstractQueue;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Queue;
/**
* An unbounded thread-safe {@linkplain Queue queue} based on linked nodes.
@ -47,9 +51,9 @@ import java.util.concurrent.atomic.*;
* queue the shortest time. New elements
* are inserted at the tail of the queue, and the queue retrieval
* operations obtain elements at the head of the queue.
* A <tt>ConcurrentLinkedQueue</tt> is an appropriate choice when
* A {@code ConcurrentLinkedQueue} is an appropriate choice when
* many threads will share access to a common collection.
* This queue does not permit <tt>null</tt> elements.
* This queue does not permit {@code null} elements.
*
* <p>This implementation employs an efficient &quot;wait-free&quot;
* algorithm based on one described in <a
@ -57,7 +61,7 @@ import java.util.concurrent.atomic.*;
* Fast, and Practical Non-Blocking and Blocking Concurrent Queue
* Algorithms</a> by Maged M. Michael and Michael L. Scott.
*
* <p>Beware that, unlike in most collections, the <tt>size</tt> method
* <p>Beware that, unlike in most collections, the {@code size} method
* is <em>NOT</em> a constant-time operation. Because of the
* asynchronous nature of these queues, determining the current number
* of elements requires a traversal of the elements.
@ -87,51 +91,102 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
private static final long serialVersionUID = 196745693267521676L;
/*
* This is a straight adaptation of Michael & Scott algorithm.
* For explanation, read the paper. The only (minor) algorithmic
* difference is that this version supports lazy deletion of
* internal nodes (method remove(Object)) -- remove CAS'es item
* fields to null. The normal queue operations unlink but then
* pass over nodes with null item fields. Similarly, iteration
* methods ignore those with nulls.
* This is a modification of the Michael & Scott algorithm,
* adapted for a garbage-collected environment, with support for
* interior node deletion (to support remove(Object)). For
* explanation, read the paper.
*
* Also note that like most non-blocking algorithms in this
* package, this implementation relies on the fact that in garbage
* Note that like most non-blocking algorithms in this package,
* this implementation relies on the fact that in garbage
* collected systems, there is no possibility of ABA problems due
* to recycled nodes, so there is no need to use "counted
* pointers" or related techniques seen in versions used in
* non-GC'ed settings.
*
* The fundamental invariants are:
* - There is exactly one (last) Node with a null next reference,
* which is CASed when enqueueing. This last Node can be
* reached in O(1) time from tail, but tail is merely an
* optimization - it can always be reached in O(N) time from
* head as well.
* - The elements contained in the queue are the non-null items in
* Nodes that are reachable from head. CASing the item
* reference of a Node to null atomically removes it from the
* queue. Reachability of all elements from head must remain
* true even in the case of concurrent modifications that cause
* head to advance. A dequeued Node may remain in use
* indefinitely due to creation of an Iterator or simply a
* poll() that has lost its time slice.
*
* The above might appear to imply that all Nodes are GC-reachable
* from a predecessor dequeued Node. That would cause two problems:
* - allow a rogue Iterator to cause unbounded memory retention
* - cause cross-generational linking of old Nodes to new Nodes if
* a Node was tenured while live, which generational GCs have a
* hard time dealing with, causing repeated major collections.
* However, only non-deleted Nodes need to be reachable from
* dequeued Nodes, and reachability does not necessarily have to
* be of the kind understood by the GC. We use the trick of
* linking a Node that has just been dequeued to itself. Such a
* self-link implicitly means to advance to head.
*
* Both head and tail are permitted to lag. In fact, failing to
* update them every time one could is a significant optimization
* (fewer CASes). This is controlled by local "hops" variables
* that only trigger helping-CASes after experiencing multiple
* lags.
*
* Since head and tail are updated concurrently and independently,
* it is possible for tail to lag behind head (why not)?
*
* CASing a Node's item reference to null atomically removes the
* element from the queue. Iterators skip over Nodes with null
* items. Prior implementations of this class had a race between
* poll() and remove(Object) where the same element would appear
* to be successfully removed by two concurrent operations. The
* method remove(Object) also lazily unlinks deleted Nodes, but
* this is merely an optimization.
*
* When constructing a Node (before enqueuing it) we avoid paying
* for a volatile write to item by using lazySet instead of a
* normal write. This allows the cost of enqueue to be
* "one-and-a-half" CASes.
*
* Both head and tail may or may not point to a Node with a
* non-null item. If the queue is empty, all items must of course
* be null. Upon creation, both head and tail refer to a dummy
* Node with null item. Both head and tail are only updated using
* CAS, so they never regress, although again this is merely an
* optimization.
*/
private static class Node<E> {
private volatile E item;
private volatile Node<E> next;
private static final
AtomicReferenceFieldUpdater<Node, Node>
nextUpdater =
AtomicReferenceFieldUpdater.newUpdater
(Node.class, Node.class, "next");
private static final
AtomicReferenceFieldUpdater<Node, Object>
itemUpdater =
AtomicReferenceFieldUpdater.newUpdater
(Node.class, Object.class, "item");
Node(E x) { item = x; }
Node(E x, Node<E> n) { item = x; next = n; }
Node(E item) {
// Piggyback on imminent casNext()
lazySetItem(item);
}
E getItem() {
return item;
}
boolean casItem(E cmp, E val) {
return itemUpdater.compareAndSet(this, cmp, val);
return UNSAFE.compareAndSwapObject(this, itemOffset, cmp, val);
}
void setItem(E val) {
itemUpdater.set(this, val);
item = val;
}
void lazySetItem(E val) {
UNSAFE.putOrderedObject(this, itemOffset, val);
}
void lazySetNext(Node<E> val) {
UNSAFE.putOrderedObject(this, nextOffset, val);
}
Node<E> getNext() {
@ -139,52 +194,55 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
}
boolean casNext(Node<E> cmp, Node<E> val) {
return nextUpdater.compareAndSet(this, cmp, val);
return UNSAFE.compareAndSwapObject(this, nextOffset, cmp, val);
}
void setNext(Node<E> val) {
nextUpdater.set(this, val);
}
// Unsafe mechanics
private static final sun.misc.Unsafe UNSAFE =
sun.misc.Unsafe.getUnsafe();
private static final long nextOffset =
objectFieldOffset(UNSAFE, "next", Node.class);
private static final long itemOffset =
objectFieldOffset(UNSAFE, "item", Node.class);
}
private static final
AtomicReferenceFieldUpdater<ConcurrentLinkedQueue, Node>
tailUpdater =
AtomicReferenceFieldUpdater.newUpdater
(ConcurrentLinkedQueue.class, Node.class, "tail");
private static final
AtomicReferenceFieldUpdater<ConcurrentLinkedQueue, Node>
headUpdater =
AtomicReferenceFieldUpdater.newUpdater
(ConcurrentLinkedQueue.class, Node.class, "head");
private boolean casTail(Node<E> cmp, Node<E> val) {
return tailUpdater.compareAndSet(this, cmp, val);
}
private boolean casHead(Node<E> cmp, Node<E> val) {
return headUpdater.compareAndSet(this, cmp, val);
}
/**
* Pointer to header node, initialized to a dummy node. The first
* actual node is at head.getNext().
* A node from which the first live (non-deleted) node (if any)
* can be reached in O(1) time.
* Invariants:
* - all live nodes are reachable from head via succ()
* - head != null
* - (tmp = head).next != tmp || tmp != head
* Non-invariants:
* - head.item may or may not be null.
* - it is permitted for tail to lag behind head, that is, for tail
* to not be reachable from head!
*/
private transient volatile Node<E> head = new Node<E>(null, null);
private transient volatile Node<E> head = new Node<E>(null);
/** Pointer to last node on list **/
/**
* A node from which the last node on list (that is, the unique
* node with node.next == null) can be reached in O(1) time.
* Invariants:
* - the last node is always reachable from tail via succ()
* - tail != null
* Non-invariants:
* - tail.item may or may not be null.
* - it is permitted for tail to lag behind head, that is, for tail
* to not be reachable from head!
* - tail.next may or may not be self-pointing to tail.
*/
private transient volatile Node<E> tail = head;
/**
* Creates a <tt>ConcurrentLinkedQueue</tt> that is initially empty.
* Creates a {@code ConcurrentLinkedQueue} that is initially empty.
*/
public ConcurrentLinkedQueue() {}
/**
* Creates a <tt>ConcurrentLinkedQueue</tt>
* Creates a {@code ConcurrentLinkedQueue}
* initially containing the elements of the given collection,
* added in traversal order of the collection's iterator.
* @param c the collection of elements to initially contain
@ -201,115 +259,143 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
/**
* Inserts the specified element at the tail of this queue.
*
* @return <tt>true</tt> (as specified by {@link Collection#add})
* @return {@code true} (as specified by {@link Collection#add})
* @throws NullPointerException if the specified element is null
*/
public boolean add(E e) {
return offer(e);
}
/**
* We don't bother to update head or tail pointers if fewer than
* HOPS links from "true" location. We assume that volatile
* writes are significantly more expensive than volatile reads.
*/
private static final int HOPS = 1;
/**
* Try to CAS head to p. If successful, repoint old head to itself
* as sentinel for succ(), below.
*/
final void updateHead(Node<E> h, Node<E> p) {
if (h != p && casHead(h, p))
h.lazySetNext(h);
}
/**
* Returns the successor of p, or the head node if p.next has been
* linked to self, which will only be true if traversing with a
* stale pointer that is now off the list.
*/
final Node<E> succ(Node<E> p) {
Node<E> next = p.getNext();
return (p == next) ? head : next;
}
/**
* Inserts the specified element at the tail of this queue.
*
* @return <tt>true</tt> (as specified by {@link Queue#offer})
* @return {@code true} (as specified by {@link Queue#offer})
* @throws NullPointerException if the specified element is null
*/
public boolean offer(E e) {
if (e == null) throw new NullPointerException();
Node<E> n = new Node<E>(e, null);
Node<E> n = new Node<E>(e);
retry:
for (;;) {
Node<E> t = tail;
Node<E> s = t.getNext();
if (t == tail) {
if (s == null) {
if (t.casNext(s, n)) {
casTail(t, n);
return true;
}
Node<E> p = t;
for (int hops = 0; ; hops++) {
Node<E> next = succ(p);
if (next != null) {
if (hops > HOPS && t != tail)
continue retry;
p = next;
} else if (p.casNext(null, n)) {
if (hops >= HOPS)
casTail(t, n); // Failure is OK.
return true;
} else {
casTail(t, s);
p = succ(p);
}
}
}
}
public E poll() {
for (;;) {
Node<E> h = head;
Node<E> t = tail;
Node<E> first = h.getNext();
if (h == head) {
if (h == t) {
if (first == null)
return null;
else
casTail(t, first);
} else if (casHead(h, first)) {
E item = first.getItem();
if (item != null) {
first.setItem(null);
return item;
}
// else skip over deleted item, continue loop,
Node<E> h = head;
Node<E> p = h;
for (int hops = 0; ; hops++) {
E item = p.getItem();
if (item != null && p.casItem(item, null)) {
if (hops >= HOPS) {
Node<E> q = p.getNext();
updateHead(h, (q != null) ? q : p);
}
return item;
}
Node<E> next = succ(p);
if (next == null) {
updateHead(h, p);
break;
}
p = next;
}
return null;
}
public E peek() { // same as poll except don't remove item
public E peek() {
Node<E> h = head;
Node<E> p = h;
E item;
for (;;) {
Node<E> h = head;
Node<E> t = tail;
Node<E> first = h.getNext();
if (h == head) {
if (h == t) {
if (first == null)
return null;
else
casTail(t, first);
} else {
E item = first.getItem();
if (item != null)
return item;
else // remove deleted node and continue
casHead(h, first);
}
item = p.getItem();
if (item != null)
break;
Node<E> next = succ(p);
if (next == null) {
break;
}
p = next;
}
updateHead(h, p);
return item;
}
/**
* Returns the first actual (non-header) node on list. This is yet
* another variant of poll/peek; here returning out the first
* node, not element (so we cannot collapse with peek() without
* introducing race.)
* Returns the first live (non-deleted) node on list, or null if none.
* This is yet another variant of poll/peek; here returning the
* first node, not element. We could make peek() a wrapper around
* first(), but that would cost an extra volatile read of item,
* and the need to add a retry loop to deal with the possibility
* of losing a race to a concurrent poll().
*/
Node<E> first() {
Node<E> h = head;
Node<E> p = h;
Node<E> result;
for (;;) {
Node<E> h = head;
Node<E> t = tail;
Node<E> first = h.getNext();
if (h == head) {
if (h == t) {
if (first == null)
return null;
else
casTail(t, first);
} else {
if (first.getItem() != null)
return first;
else // remove deleted node and continue
casHead(h, first);
}
E item = p.getItem();
if (item != null) {
result = p;
break;
}
Node<E> next = succ(p);
if (next == null) {
result = null;
break;
}
p = next;
}
updateHead(h, p);
return result;
}
/**
* Returns <tt>true</tt> if this queue contains no elements.
* Returns {@code true} if this queue contains no elements.
*
* @return <tt>true</tt> if this queue contains no elements
* @return {@code true} if this queue contains no elements
*/
public boolean isEmpty() {
return first() == null;
@ -317,8 +403,8 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
/**
* Returns the number of elements in this queue. If this queue
* contains more than <tt>Integer.MAX_VALUE</tt> elements, returns
* <tt>Integer.MAX_VALUE</tt>.
* contains more than {@code Integer.MAX_VALUE} elements, returns
* {@code Integer.MAX_VALUE}.
*
* <p>Beware that, unlike in most collections, this method is
* <em>NOT</em> a constant-time operation. Because of the
@ -329,7 +415,7 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
*/
public int size() {
int count = 0;
for (Node<E> p = first(); p != null; p = p.getNext()) {
for (Node<E> p = first(); p != null; p = succ(p)) {
if (p.getItem() != null) {
// Collections.size() spec says to max out
if (++count == Integer.MAX_VALUE)
@ -340,16 +426,16 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
}
/**
* Returns <tt>true</tt> if this queue contains the specified element.
* More formally, returns <tt>true</tt> if and only if this queue contains
* at least one element <tt>e</tt> such that <tt>o.equals(e)</tt>.
* Returns {@code true} if this queue contains the specified element.
* More formally, returns {@code true} if and only if this queue contains
* at least one element {@code e} such that {@code o.equals(e)}.
*
* @param o object to be checked for containment in this queue
* @return <tt>true</tt> if this queue contains the specified element
* @return {@code true} if this queue contains the specified element
*/
public boolean contains(Object o) {
if (o == null) return false;
for (Node<E> p = first(); p != null; p = p.getNext()) {
for (Node<E> p = first(); p != null; p = succ(p)) {
E item = p.getItem();
if (item != null &&
o.equals(item))
@ -360,23 +446,29 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
/**
* Removes a single instance of the specified element from this queue,
* if it is present. More formally, removes an element <tt>e</tt> such
* that <tt>o.equals(e)</tt>, if this queue contains one or more such
* if it is present. More formally, removes an element {@code e} such
* that {@code o.equals(e)}, if this queue contains one or more such
* elements.
* Returns <tt>true</tt> if this queue contained the specified element
* Returns {@code true} if this queue contained the specified element
* (or equivalently, if this queue changed as a result of the call).
*
* @param o element to be removed from this queue, if present
* @return <tt>true</tt> if this queue changed as a result of the call
* @return {@code true} if this queue changed as a result of the call
*/
public boolean remove(Object o) {
if (o == null) return false;
for (Node<E> p = first(); p != null; p = p.getNext()) {
Node<E> pred = null;
for (Node<E> p = first(); p != null; p = succ(p)) {
E item = p.getItem();
if (item != null &&
o.equals(item) &&
p.casItem(item, null))
p.casItem(item, null)) {
Node<E> next = succ(p);
if (pred != null && next != null)
pred.casNext(p, next);
return true;
}
pred = p;
}
return false;
}
@ -397,7 +489,7 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
public Object[] toArray() {
// Use ArrayList to deal with resizing.
ArrayList<E> al = new ArrayList<E>();
for (Node<E> p = first(); p != null; p = p.getNext()) {
for (Node<E> p = first(); p != null; p = succ(p)) {
E item = p.getItem();
if (item != null)
al.add(item);
@ -415,22 +507,22 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
* <p>If this queue fits in the specified array with room to spare
* (i.e., the array has more elements than this queue), the element in
* the array immediately following the end of the queue is set to
* <tt>null</tt>.
* {@code null}.
*
* <p>Like the {@link #toArray()} method, this method acts as bridge between
* array-based and collection-based APIs. Further, this method allows
* precise control over the runtime type of the output array, and may,
* under certain circumstances, be used to save allocation costs.
*
* <p>Suppose <tt>x</tt> is a queue known to contain only strings.
* <p>Suppose {@code x} is a queue known to contain only strings.
* The following code can be used to dump the queue into a newly
* allocated array of <tt>String</tt>:
* allocated array of {@code String}:
*
* <pre>
* String[] y = x.toArray(new String[0]);</pre>
*
* Note that <tt>toArray(new Object[0])</tt> is identical in function to
* <tt>toArray()</tt>.
* Note that {@code toArray(new Object[0])} is identical in function to
* {@code toArray()}.
*
* @param a the array into which the elements of the queue are to
* be stored, if it is big enough; otherwise, a new array of the
@ -441,11 +533,12 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
* this queue
* @throws NullPointerException if the specified array is null
*/
@SuppressWarnings("unchecked")
public <T> T[] toArray(T[] a) {
// try to use sent-in array
int k = 0;
Node<E> p;
for (p = first(); p != null && k < a.length; p = p.getNext()) {
for (p = first(); p != null && k < a.length; p = succ(p)) {
E item = p.getItem();
if (item != null)
a[k++] = (T)item;
@ -458,7 +551,7 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
// If won't fit, use ArrayList version
ArrayList<E> al = new ArrayList<E>();
for (Node<E> q = first(); q != null; q = q.getNext()) {
for (Node<E> q = first(); q != null; q = succ(q)) {
E item = q.getItem();
if (item != null)
al.add(item);
@ -469,7 +562,8 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
/**
* Returns an iterator over the elements in this queue in proper sequence.
* The returned iterator is a "weakly consistent" iterator that
* will never throw {@link ConcurrentModificationException},
* will never throw {@link java.util.ConcurrentModificationException
* ConcurrentModificationException},
* and guarantees to traverse elements as they existed upon
* construction of the iterator, and may (but is not guaranteed to)
* reflect any modifications subsequent to construction.
@ -511,7 +605,15 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
lastRet = nextNode;
E x = nextItem;
Node<E> p = (nextNode == null)? first() : nextNode.getNext();
Node<E> pred, p;
if (nextNode == null) {
p = first();
pred = null;
} else {
pred = nextNode;
p = succ(nextNode);
}
for (;;) {
if (p == null) {
nextNode = null;
@ -523,8 +625,13 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
nextNode = p;
nextItem = item;
return x;
} else // skip over nulls
p = p.getNext();
} else {
// skip over nulls
Node<E> next = succ(p);
if (pred != null && next != null)
pred.casNext(p, next);
p = next;
}
}
}
@ -549,7 +656,7 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
/**
* Save the state to a stream (that is, serialize it).
*
* @serialData All of the elements (each an <tt>E</tt>) in
* @serialData All of the elements (each an {@code E}) in
* the proper order, followed by a null
* @param s the stream
*/
@ -560,7 +667,7 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
s.defaultWriteObject();
// Write out all elements in the proper order.
for (Node<E> p = first(); p != null; p = p.getNext()) {
for (Node<E> p = first(); p != null; p = succ(p)) {
Object item = p.getItem();
if (item != null)
s.writeObject(item);
@ -579,10 +686,11 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
throws java.io.IOException, ClassNotFoundException {
// Read in capacity, and any hidden stuff
s.defaultReadObject();
head = new Node<E>(null, null);
head = new Node<E>(null);
tail = head;
// Read in all elements and place in queue
for (;;) {
@SuppressWarnings("unchecked")
E item = (E)s.readObject();
if (item == null)
break;
@ -591,4 +699,35 @@ public class ConcurrentLinkedQueue<E> extends AbstractQueue<E>
}
}
// Unsafe mechanics
private static final sun.misc.Unsafe UNSAFE = sun.misc.Unsafe.getUnsafe();
private static final long headOffset =
objectFieldOffset(UNSAFE, "head", ConcurrentLinkedQueue.class);
private static final long tailOffset =
objectFieldOffset(UNSAFE, "tail", ConcurrentLinkedQueue.class);
private boolean casTail(Node<E> cmp, Node<E> val) {
return UNSAFE.compareAndSwapObject(this, tailOffset, cmp, val);
}
private boolean casHead(Node<E> cmp, Node<E> val) {
return UNSAFE.compareAndSwapObject(this, headOffset, cmp, val);
}
private void lazySetHead(Node<E> val) {
UNSAFE.putOrderedObject(this, headOffset, val);
}
static long objectFieldOffset(sun.misc.Unsafe UNSAFE,
String field, Class<?> klazz) {
try {
return UNSAFE.objectFieldOffset(klazz.getDeclaredField(field));
} catch (NoSuchFieldException e) {
// Convert Exception to corresponding Error
NoSuchFieldError error = new NoSuchFieldError(field);
error.initCause(e);
throw error;
}
}
}

400
jdk/src/share/classes/java/util/concurrent/LinkedBlockingDeque.java
View File

@ -34,8 +34,13 @@
*/
package java.util.concurrent;
import java.util.*;
import java.util.concurrent.locks.*;
import java.util.AbstractQueue;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
/**
* An optionally-bounded {@linkplain BlockingDeque blocking deque} based on
@ -73,6 +78,20 @@ public class LinkedBlockingDeque<E>
/*
* Implemented as a simple doubly-linked list protected by a
* single lock and using conditions to manage blocking.
*
* To implement weakly consistent iterators, it appears we need to
* keep all Nodes GC-reachable from a predecessor dequeued Node.
* That would cause two problems:
* - allow a rogue Iterator to cause unbounded memory retention
* - cause cross-generational linking of old Nodes to new Nodes if
* a Node was tenured while live, which generational GCs have a
* hard time dealing with, causing repeated major collections.
* However, only non-deleted Nodes need to be reachable from
* dequeued Nodes, and reachability does not necessarily have to
* be of the kind understood by the GC. We use the trick of
* linking a Node that has just been dequeued to itself. Such a
* self-link implicitly means to jump to "first" (for next links)
* or "last" (for prev links).
*/
/*
@ -86,9 +105,27 @@ public class LinkedBlockingDeque<E>
/** Doubly-linked list node class */
static final class Node<E> {
/**
* The item, or null if this node has been removed.
*/
E item;
/**
* One of:
* - the real predecessor Node
* - this Node, meaning the predecessor is tail
* - null, meaning there is no predecessor
*/
Node<E> prev;
/**
* One of:
* - the real successor Node
* - this Node, meaning the successor is head
* - null, meaning there is no successor
*/
Node<E> next;
Node(E x, Node<E> p, Node<E> n) {
item = x;
prev = p;
@ -96,23 +133,37 @@ public class LinkedBlockingDeque<E>
}
}
/** Pointer to first node */
private transient Node<E> first;
/** Pointer to last node */
private transient Node<E> last;
/**
* Pointer to first node.
* Invariant: (first == null && last == null) ||
* (first.prev == null && first.item != null)
*/
transient Node<E> first;
/**
* Pointer to last node.
* Invariant: (first == null && last == null) ||
* (last.next == null && last.item != null)
*/
transient Node<E> last;
/** Number of items in the deque */
private transient int count;
/** Maximum number of items in the deque */
private final int capacity;
/** Main lock guarding all access */
private final ReentrantLock lock = new ReentrantLock();
final ReentrantLock lock = new ReentrantLock();
/** Condition for waiting takes */
private final Condition notEmpty = lock.newCondition();
/** Condition for waiting puts */
private final Condition notFull = lock.newCondition();
/**
* Creates a <tt>LinkedBlockingDeque</tt> with a capacity of
* Creates a {@code LinkedBlockingDeque} with a capacity of
* {@link Integer#MAX_VALUE}.
*/
public LinkedBlockingDeque() {
@ -120,10 +171,10 @@ public class LinkedBlockingDeque<E>
}
/**
* Creates a <tt>LinkedBlockingDeque</tt> with the given (fixed) capacity.
* Creates a {@code LinkedBlockingDeque} with the given (fixed) capacity.
*
* @param capacity the capacity of this deque
* @throws IllegalArgumentException if <tt>capacity</tt> is less than 1
* @throws IllegalArgumentException if {@code capacity} is less than 1
*/
public LinkedBlockingDeque(int capacity) {
if (capacity <= 0) throw new IllegalArgumentException();
@ -131,7 +182,7 @@ public class LinkedBlockingDeque<E>
}
/**
* Creates a <tt>LinkedBlockingDeque</tt> with a capacity of
* Creates a {@code LinkedBlockingDeque} with a capacity of
* {@link Integer#MAX_VALUE}, initially containing the elements of
* the given collection, added in traversal order of the
* collection's iterator.
@ -142,8 +193,18 @@ public class LinkedBlockingDeque<E>
*/
public LinkedBlockingDeque(Collection<? extends E> c) {
this(Integer.MAX_VALUE);
for (E e : c)
add(e);
final ReentrantLock lock = this.lock;
lock.lock(); // Never contended, but necessary for visibility
try {
for (E e : c) {
if (e == null)
throw new NullPointerException();
if (!linkLast(e))
throw new IllegalStateException("Deque full");
}
} finally {
lock.unlock();
}
}
@ -153,9 +214,9 @@ public class LinkedBlockingDeque<E>
* Links e as first element, or returns false if full.
*/
private boolean linkFirst(E e) {
// assert lock.isHeldByCurrentThread();
if (count >= capacity)
return false;
++count;
Node<E> f = first;
Node<E> x = new Node<E>(e, null, f);
first = x;
@ -163,6 +224,7 @@ public class LinkedBlockingDeque<E>
last = x;
else
f.prev = x;
++count;
notEmpty.signal();
return true;
}
@ -171,9 +233,9 @@ public class LinkedBlockingDeque<E>
* Links e as last element, or returns false if full.
*/
private boolean linkLast(E e) {
// assert lock.isHeldByCurrentThread();
if (count >= capacity)
return false;
++count;
Node<E> l = last;
Node<E> x = new Node<E>(e, l, null);
last = x;
@ -181,6 +243,7 @@ public class LinkedBlockingDeque<E>
first = x;
else
l.next = x;
++count;
notEmpty.signal();
return true;
}
@ -189,10 +252,14 @@ public class LinkedBlockingDeque<E>
* Removes and returns first element, or null if empty.
*/
private E unlinkFirst() {
// assert lock.isHeldByCurrentThread();
Node<E> f = first;
if (f == null)
return null;
Node<E> n = f.next;
E item = f.item;
f.item = null;
f.next = f; // help GC
first = n;
if (n == null)
last = null;
@ -200,17 +267,21 @@ public class LinkedBlockingDeque<E>
n.prev = null;
--count;
notFull.signal();
return f.item;
return item;
}
/**
* Removes and returns last element, or null if empty.
*/
private E unlinkLast() {
// assert lock.isHeldByCurrentThread();
Node<E> l = last;
if (l == null)
return null;
Node<E> p = l.prev;
E item = l.item;
l.item = null;
l.prev = l; // help GC
last = p;
if (p == null)
first = null;
@ -218,31 +289,29 @@ public class LinkedBlockingDeque<E>
p.next = null;
--count;
notFull.signal();
return l.item;
return item;
}
/**
* Unlink e
* Unlinks x.
*/
private void unlink(Node<E> x) {
void unlink(Node<E> x) {
// assert lock.isHeldByCurrentThread();
Node<E> p = x.prev;
Node<E> n = x.next;
if (p == null) {
if (n == null)
first = last = null;
else {
n.prev = null;
first = n;
}
unlinkFirst();
} else if (n == null) {
p.next = null;
last = p;
unlinkLast();
} else {
p.next = n;
n.prev = p;
x.item = null;
// Don't mess with x's links. They may still be in use by
// an iterator.
--count;
notFull.signal();
}
--count;
notFull.signalAll();
}
// BlockingDeque methods
@ -270,6 +339,7 @@ public class LinkedBlockingDeque<E>
*/
public boolean offerFirst(E e) {
if (e == null) throw new NullPointerException();
final ReentrantLock lock = this.lock;
lock.lock();
try {
return linkFirst(e);
@ -283,6 +353,7 @@ public class LinkedBlockingDeque<E>
*/
public boolean offerLast(E e) {
if (e == null) throw new NullPointerException();
final ReentrantLock lock = this.lock;
lock.lock();
try {
return linkLast(e);
@ -297,6 +368,7 @@ public class LinkedBlockingDeque<E>
*/
public void putFirst(E e) throws InterruptedException {
if (e == null) throw new NullPointerException();
final ReentrantLock lock = this.lock;
lock.lock();
try {
while (!linkFirst(e))
@ -312,6 +384,7 @@ public class LinkedBlockingDeque<E>
*/
public void putLast(E e) throws InterruptedException {
if (e == null) throw new NullPointerException();
final ReentrantLock lock = this.lock;
lock.lock();
try {
while (!linkLast(e))
@ -329,15 +402,15 @@ public class LinkedBlockingDeque<E>
throws InterruptedException {
if (e == null) throw new NullPointerException();
long nanos = unit.toNanos(timeout);
final ReentrantLock lock = this.lock;
lock.lockInterruptibly();
try {
for (;;) {
if (linkFirst(e))
return true;
while (!linkFirst(e)) {
if (nanos <= 0)
return false;
nanos = notFull.awaitNanos(nanos);
}
return true;
} finally {
lock.unlock();
}
@ -351,15 +424,15 @@ public class LinkedBlockingDeque<E>
throws InterruptedException {
if (e == null) throw new NullPointerException();
long nanos = unit.toNanos(timeout);
final ReentrantLock lock = this.lock;
lock.lockInterruptibly();
try {
for (;;) {
if (linkLast(e))
return true;
while (!linkLast(e)) {
if (nanos <= 0)
return false;
nanos = notFull.awaitNanos(nanos);
}
return true;
} finally {
lock.unlock();
}
@ -384,6 +457,7 @@ public class LinkedBlockingDeque<E>
}
public E pollFirst() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
return unlinkFirst();
@ -393,6 +467,7 @@ public class LinkedBlockingDeque<E>
}
public E pollLast() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
return unlinkLast();
@ -402,6 +477,7 @@ public class LinkedBlockingDeque<E>
}
public E takeFirst() throws InterruptedException {
final ReentrantLock lock = this.lock;
lock.lock();
try {
E x;
@ -414,6 +490,7 @@ public class LinkedBlockingDeque<E>
}
public E takeLast() throws InterruptedException {
final ReentrantLock lock = this.lock;
lock.lock();
try {
E x;
@ -428,16 +505,16 @@ public class LinkedBlockingDeque<E>
public E pollFirst(long timeout, TimeUnit unit)
throws InterruptedException {
long nanos = unit.toNanos(timeout);
final ReentrantLock lock = this.lock;
lock.lockInterruptibly();
try {
for (;;) {
E x = unlinkFirst();
if (x != null)
return x;
E x;
while ( (x = unlinkFirst()) == null) {
if (nanos <= 0)
return null;
nanos = notEmpty.awaitNanos(nanos);
}
return x;
} finally {
lock.unlock();
}
@ -446,16 +523,16 @@ public class LinkedBlockingDeque<E>
public E pollLast(long timeout, TimeUnit unit)
throws InterruptedException {
long nanos = unit.toNanos(timeout);
final ReentrantLock lock = this.lock;
lock.lockInterruptibly();
try {
for (;;) {
E x = unlinkLast();
if (x != null)
return x;
E x;
while ( (x = unlinkLast()) == null) {
if (nanos <= 0)
return null;
nanos = notEmpty.awaitNanos(nanos);
}
return x;
} finally {
lock.unlock();
}
@ -480,6 +557,7 @@ public class LinkedBlockingDeque<E>
}
public E peekFirst() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
return (first == null) ? null : first.item;
@ -489,6 +567,7 @@ public class LinkedBlockingDeque<E>
}
public E peekLast() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
return (last == null) ? null : last.item;
@ -499,6 +578,7 @@ public class LinkedBlockingDeque<E>
public boolean removeFirstOccurrence(Object o) {
if (o == null) return false;
final ReentrantLock lock = this.lock;
lock.lock();
try {
for (Node<E> p = first; p != null; p = p.next) {
@ -515,6 +595,7 @@ public class LinkedBlockingDeque<E>
public boolean removeLastOccurrence(Object o) {
if (o == null) return false;
final ReentrantLock lock = this.lock;
lock.lock();
try {
for (Node<E> p = last; p != null; p = p.prev) {
@ -619,14 +700,15 @@ public class LinkedBlockingDeque<E>
* Returns the number of additional elements that this deque can ideally
* (in the absence of memory or resource constraints) accept without
* blocking. This is always equal to the initial capacity of this deque
* less the current <tt>size</tt> of this deque.
* less the current {@code size} of this deque.
*
* <p>Note that you <em>cannot</em> always tell if an attempt to insert
* an element will succeed by inspecting <tt>remainingCapacity</tt>
* an element will succeed by inspecting {@code remainingCapacity}
* because it may be the case that another thread is about to
* insert or remove an element.
*/
public int remainingCapacity() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
return capacity - count;
@ -642,22 +724,7 @@ public class LinkedBlockingDeque<E>
* @throws IllegalArgumentException {@inheritDoc}
*/
public int drainTo(Collection<? super E> c) {
if (c == null)
throw new NullPointerException();
if (c == this)
throw new IllegalArgumentException();
lock.lock();
try {
for (Node<E> p = first; p != null; p = p.next)
c.add(p.item);
int n = count;
count = 0;
first = last = null;
notFull.signalAll();
return n;
} finally {
lock.unlock();
}
return drainTo(c, Integer.MAX_VALUE);
}
/**
@ -671,19 +738,14 @@ public class LinkedBlockingDeque<E>
throw new NullPointerException();
if (c == this)
throw new IllegalArgumentException();
final ReentrantLock lock = this.lock;
lock.lock();
try {
int n = 0;
while (n < maxElements && first != null) {
c.add(first.item);
first.prev = null;
first = first.next;
--count;
++n;
int n = Math.min(maxElements, count);
for (int i = 0; i < n; i++) {
c.add(first.item); // In this order, in case add() throws.
unlinkFirst();
}
if (first == null)
last = null;
notFull.signalAll();
return n;
} finally {
lock.unlock();
@ -712,16 +774,16 @@ public class LinkedBlockingDeque<E>
/**
* Removes the first occurrence of the specified element from this deque.
* If the deque does not contain the element, it is unchanged.
* More formally, removes the first element <tt>e</tt> such that
* <tt>o.equals(e)</tt> (if such an element exists).
* Returns <tt>true</tt> if this deque contained the specified element
* More formally, removes the first element {@code e} such that
* {@code o.equals(e)} (if such an element exists).
* Returns {@code true} if this deque contained the specified element
* (or equivalently, if this deque changed as a result of the call).
*
* <p>This method is equivalent to
* {@link #removeFirstOccurrence(Object) removeFirstOccurrence}.
*
* @param o element to be removed from this deque, if present
* @return <tt>true</tt> if this deque changed as a result of the call
* @return {@code true} if this deque changed as a result of the call
*/
public boolean remove(Object o) {
return removeFirstOccurrence(o);
@ -733,6 +795,7 @@ public class LinkedBlockingDeque<E>
* @return the number of elements in this deque
*/
public int size() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
return count;
@ -742,15 +805,16 @@ public class LinkedBlockingDeque<E>
}
/**
* Returns <tt>true</tt> if this deque contains the specified element.
* More formally, returns <tt>true</tt> if and only if this deque contains
* at least one element <tt>e</tt> such that <tt>o.equals(e)</tt>.
* Returns {@code true} if this deque contains the specified element.
* More formally, returns {@code true} if and only if this deque contains
* at least one element {@code e} such that {@code o.equals(e)}.
*
* @param o object to be checked for containment in this deque
* @return <tt>true</tt> if this deque contains the specified element
* @return {@code true} if this deque contains the specified element
*/
public boolean contains(Object o) {
if (o == null) return false;
final ReentrantLock lock = this.lock;
lock.lock();
try {
for (Node<E> p = first; p != null; p = p.next)
@ -762,24 +826,46 @@ public class LinkedBlockingDeque<E>
}
}
/**
* Variant of removeFirstOccurrence needed by iterator.remove.
* Searches for the node, not its contents.
/*
* TODO: Add support for more efficient bulk operations.
*
* We don't want to acquire the lock for every iteration, but we
* also want other threads a chance to interact with the
* collection, especially when count is close to capacity.
*/
boolean removeNode(Node<E> e) {
lock.lock();
try {
for (Node<E> p = first; p != null; p = p.next) {
if (p == e) {
unlink(p);
return true;
}
}
return false;
} finally {
lock.unlock();
}
}
// /**
// * Adds all of the elements in the specified collection to this
// * queue. Attempts to addAll of a queue to itself result in
// * {@code IllegalArgumentException}. Further, the behavior of
// * this operation is undefined if the specified collection is
// * modified while the operation is in progress.
// *
// * @param c collection containing elements to be added to this queue
// * @return {@code true} if this queue changed as a result of the call
// * @throws ClassCastException {@inheritDoc}
// * @throws NullPointerException {@inheritDoc}
// * @throws IllegalArgumentException {@inheritDoc}
// * @throws IllegalStateException {@inheritDoc}
// * @see #add(Object)
// */
// public boolean addAll(Collection<? extends E> c) {
// if (c == null)
// throw new NullPointerException();
// if (c == this)
// throw new IllegalArgumentException();
// final ReentrantLock lock = this.lock;
// lock.lock();
// try {
// boolean modified = false;
// for (E e : c)
// if (linkLast(e))
// modified = true;
// return modified;
// } finally {
// lock.unlock();
// }
// }
/**
* Returns an array containing all of the elements in this deque, in
@ -794,7 +880,9 @@ public class LinkedBlockingDeque<E>
*
* @return an array containing all of the elements in this deque
*/
@SuppressWarnings("unchecked")
public Object[] toArray() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
Object[] a = new Object[count];
@ -817,22 +905,22 @@ public class LinkedBlockingDeque<E>
* <p>If this deque fits in the specified array with room to spare
* (i.e., the array has more elements than this deque), the element in
* the array immediately following the end of the deque is set to
* <tt>null</tt>.
* {@code null}.
*
* <p>Like the {@link #toArray()} method, this method acts as bridge between
* array-based and collection-based APIs. Further, this method allows
* precise control over the runtime type of the output array, and may,
* under certain circumstances, be used to save allocation costs.
*
* <p>Suppose <tt>x</tt> is a deque known to contain only strings.
* <p>Suppose {@code x} is a deque known to contain only strings.
* The following code can be used to dump the deque into a newly
* allocated array of <tt>String</tt>:
* allocated array of {@code String}:
*
* <pre>
* String[] y = x.toArray(new String[0]);</pre>
*
* Note that <tt>toArray(new Object[0])</tt> is identical in function to
* <tt>toArray()</tt>.
* Note that {@code toArray(new Object[0])} is identical in function to
* {@code toArray()}.
*
* @param a the array into which the elements of the deque are to
* be stored, if it is big enough; otherwise, a new array of the
@ -843,14 +931,14 @@ public class LinkedBlockingDeque<E>
* this deque
* @throws NullPointerException if the specified array is null
*/
@SuppressWarnings("unchecked")
public <T> T[] toArray(T[] a) {
final ReentrantLock lock = this.lock;
lock.lock();
try {
if (a.length < count)
a = (T[])java.lang.reflect.Array.newInstance(
a.getClass().getComponentType(),
count
);
a = (T[])java.lang.reflect.Array.newInstance
(a.getClass().getComponentType(), count);
int k = 0;
for (Node<E> p = first; p != null; p = p.next)
@ -864,6 +952,7 @@ public class LinkedBlockingDeque<E>
}
public String toString() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
return super.toString();
@ -877,8 +966,16 @@ public class LinkedBlockingDeque<E>
* The deque will be empty after this call returns.
*/
public void clear() {
final ReentrantLock lock = this.lock;
lock.lock();
try {
for (Node<E> f = first; f != null; ) {
f.item = null;
Node<E> n = f.next;
f.prev = null;
f.next = null;
f = n;
}
first = last = null;
count = 0;
notFull.signalAll();
@ -890,8 +987,9 @@ public class LinkedBlockingDeque<E>
/**
* Returns an iterator over the elements in this deque in proper sequence.
* The elements will be returned in order from first (head) to last (tail).
* The returned <tt>Iterator</tt> is a "weakly consistent" iterator that
* will never throw {@link ConcurrentModificationException},
* The returned {@code Iterator} is a "weakly consistent" iterator that
* will never throw {@link java.util.ConcurrentModificationException
* ConcurrentModificationException},
* and guarantees to traverse elements as they existed upon
* construction of the iterator, and may (but is not guaranteed to)
* reflect any modifications subsequent to construction.
@ -906,8 +1004,9 @@ public class LinkedBlockingDeque<E>
* Returns an iterator over the elements in this deque in reverse
* sequential order. The elements will be returned in order from
* last (tail) to first (head).
* The returned <tt>Iterator</tt> is a "weakly consistent" iterator that
* will never throw {@link ConcurrentModificationException},
* The returned {@code Iterator} is a "weakly consistent" iterator that
* will never throw {@link java.util.ConcurrentModificationException
* ConcurrentModificationException},
* and guarantees to traverse elements as they existed upon
* construction of the iterator, and may (but is not guaranteed to)
* reflect any modifications subsequent to construction.
@ -921,7 +1020,7 @@ public class LinkedBlockingDeque<E>
*/
private abstract class AbstractItr implements Iterator<E> {
/**
* The next node to return in next
* The next node to return in next()
*/
Node<E> next;
@ -939,15 +1038,44 @@ public class LinkedBlockingDeque<E>
*/
private Node<E> lastRet;
abstract Node<E> firstNode();
abstract Node<E> nextNode(Node<E> n);
AbstractItr() {
advance(); // set to initial position
// set to initial position
final ReentrantLock lock = LinkedBlockingDeque.this.lock;
lock.lock();
try {
next = firstNode();
nextItem = (next == null) ? null : next.item;
} finally {
lock.unlock();
}
}
/**
* Advances next, or if not yet initialized, sets to first node.
* Implemented to move forward vs backward in the two subclasses.
* Advances next.
*/
abstract void advance();
void advance() {
final ReentrantLock lock = LinkedBlockingDeque.this.lock;
lock.lock();
try {
// assert next != null;
Node<E> s = nextNode(next);
if (s == next) {
next = firstNode();
} else {
// Skip over removed nodes.
// May be necessary if multiple interior Nodes are removed.
while (s != null && s.item == null)
s = nextNode(s);
next = s;
}
nextItem = (next == null) ? null : next.item;
} finally {
lock.unlock();
}
}
public boolean hasNext() {
return next != null;
@ -967,52 +1095,39 @@ public class LinkedBlockingDeque<E>
if (n == null)
throw new IllegalStateException();
lastRet = null;
// Note: removeNode rescans looking for this node to make
// sure it was not already removed. Otherwise, trying to
// re-remove could corrupt list.
removeNode(n);
final ReentrantLock lock = LinkedBlockingDeque.this.lock;
lock.lock();
try {
if (n.item != null)
unlink(n);
} finally {
lock.unlock();
}
}
}
/** Forward iterator */
private class Itr extends AbstractItr {
void advance() {
final ReentrantLock lock = LinkedBlockingDeque.this.lock;
lock.lock();
try {
next = (next == null)? first : next.next;
nextItem = (next == null)? null : next.item;
} finally {
lock.unlock();
}
}
Node<E> firstNode() { return first; }
Node<E> nextNode(Node<E> n) { return n.next; }
}
/**
* Descending iterator for LinkedBlockingDeque
*/
/** Descending iterator */
private class DescendingItr extends AbstractItr {
void advance() {
final ReentrantLock lock = LinkedBlockingDeque.this.lock;
lock.lock();
try {
next = (next == null)? last : next.prev;
nextItem = (next == null)? null : next.item;
} finally {
lock.unlock();
}
}
Node<E> firstNode() { return last; }
Node<E> nextNode(Node<E> n) { return n.prev; }
}
/**
* Save the state of this deque to a stream (that is, serialize it).
*
* @serialData The capacity (int), followed by elements (each an
* <tt>Object</tt>) in the proper order, followed by a null
* {@code Object}) in the proper order, followed by a null
* @param s the stream
*/
private void writeObject(java.io.ObjectOutputStream s)
throws java.io.IOException {
final ReentrantLock lock = this.lock;
lock.lock();
try {
// Write out capacity and any hidden stuff
@ -1040,6 +1155,7 @@ public class LinkedBlockingDeque<E>
last = null;
// Read in all elements and place in queue
for (;;) {
@SuppressWarnings("unchecked")
E item = (E)s.readObject();
if (item == null)
break;

406
jdk/src/share/classes/java/util/concurrent/LinkedBlockingQueue.java
View File

@ -34,9 +34,14 @@
*/
package java.util.concurrent;
import java.util.concurrent.atomic.*;
import java.util.concurrent.locks.*;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import java.util.AbstractQueue;
import java.util.Collection;
import java.util.Iterator;
import java.util.NoSuchElementException;
/**
* An optionally-bounded {@linkplain BlockingQueue blocking queue} based on
@ -86,15 +91,43 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
* items have been entered since the signal. And symmetrically for
* takes signalling puts. Operations such as remove(Object) and
* iterators acquire both locks.
*
* Visibility between writers and readers is provided as follows:
*
* Whenever an element is enqueued, the putLock is acquired and
* count updated. A subsequent reader guarantees visibility to the
* enqueued Node by either acquiring the putLock (via fullyLock)
* or by acquiring the takeLock, and then reading n = count.get();
* this gives visibility to the first n items.
*
* To implement weakly consistent iterators, it appears we need to
* keep all Nodes GC-reachable from a predecessor dequeued Node.
* That would cause two problems:
* - allow a rogue Iterator to cause unbounded memory retention
* - cause cross-generational linking of old Nodes to new Nodes if
* a Node was tenured while live, which generational GCs have a
* hard time dealing with, causing repeated major collections.
* However, only non-deleted Nodes need to be reachable from
* dequeued Nodes, and reachability does not necessarily have to
* be of the kind understood by the GC. We use the trick of
* linking a Node that has just been dequeued to itself. Such a
* self-link implicitly means to advance to head.next.
*/
/**
* Linked list node class
*/
static class Node<E> {
/** The item, volatile to ensure barrier separating write and read */
volatile E item;
E item;
/**
* One of:
* - the real successor Node
* - this Node, meaning the successor is head.next
* - null, meaning there is no successor (this is the last node)
*/
Node<E> next;
Node(E x) { item = x; }
}
@ -104,10 +137,16 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
/** Current number of elements */
private final AtomicInteger count = new AtomicInteger(0);
/** Head of linked list */
/**
* Head of linked list.
* Invariant: head.item == null
*/
private transient Node<E> head;
/** Tail of linked list */
/**
* Tail of linked list.
* Invariant: last.next == null
*/
private transient Node<E> last;
/** Lock held by take, poll, etc */
@ -151,18 +190,26 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
/**
* Creates a node and links it at end of queue.
*
* @param x the item
*/
private void insert(E x) {
private void enqueue(E x) {
// assert putLock.isHeldByCurrentThread();
// assert last.next == null;
last = last.next = new Node<E>(x);
}
/**
* Removes a node from head of queue,
* Removes a node from head of queue.
*
* @return the node
*/
private E extract() {
Node<E> first = head.next;
private E dequeue() {
// assert takeLock.isHeldByCurrentThread();
// assert head.item == null;
Node<E> h = head;
Node<E> first = h.next;
h.next = h; // help GC
head = first;
E x = first.item;
first.item = null;
@ -172,7 +219,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
/**
* Lock to prevent both puts and takes.
*/
private void fullyLock() {
void fullyLock() {
putLock.lock();
takeLock.lock();
}
@ -180,14 +227,21 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
/**
* Unlock to allow both puts and takes.
*/
private void fullyUnlock() {
void fullyUnlock() {
takeLock.unlock();
putLock.unlock();
}
// /**
// * Tells whether both locks are held by current thread.
// */
// boolean isFullyLocked() {
// return (putLock.isHeldByCurrentThread() &&
// takeLock.isHeldByCurrentThread());
// }
/**
* Creates a <tt>LinkedBlockingQueue</tt> with a capacity of
* Creates a {@code LinkedBlockingQueue} with a capacity of
* {@link Integer#MAX_VALUE}.
*/
public LinkedBlockingQueue() {
@ -195,10 +249,10 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
}
/**
* Creates a <tt>LinkedBlockingQueue</tt> with the given (fixed) capacity.
* Creates a {@code LinkedBlockingQueue} with the given (fixed) capacity.
*
* @param capacity the capacity of this queue
* @throws IllegalArgumentException if <tt>capacity</tt> is not greater
* @throws IllegalArgumentException if {@code capacity} is not greater
* than zero
*/
public LinkedBlockingQueue(int capacity) {
@ -208,7 +262,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
}
/**
* Creates a <tt>LinkedBlockingQueue</tt> with a capacity of
* Creates a {@code LinkedBlockingQueue} with a capacity of
* {@link Integer#MAX_VALUE}, initially containing the elements of the
* given collection,
* added in traversal order of the collection's iterator.
@ -219,8 +273,22 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
*/
public LinkedBlockingQueue(Collection<? extends E> c) {
this(Integer.MAX_VALUE);
for (E e : c)
add(e);
final ReentrantLock putLock = this.putLock;
putLock.lock(); // Never contended, but necessary for visibility
try {
int n = 0;
for (E e : c) {
if (e == null)
throw new NullPointerException();
if (n == capacity)
throw new IllegalStateException("Queue full");
enqueue(e);
++n;
}
count.set(n);
} finally {
putLock.unlock();
}
}
@ -241,10 +309,10 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
* Returns the number of additional elements that this queue can ideally
* (in the absence of memory or resource constraints) accept without
* blocking. This is always equal to the initial capacity of this queue
* less the current <tt>size</tt> of this queue.
* less the current {@code size} of this queue.
*
* <p>Note that you <em>cannot</em> always tell if an attempt to insert
* an element will succeed by inspecting <tt>remainingCapacity</tt>
* an element will succeed by inspecting {@code remainingCapacity}
* because it may be the case that another thread is about to
* insert or remove an element.
*/
@ -261,8 +329,8 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
*/
public void put(E e) throws InterruptedException {
if (e == null) throw new NullPointerException();
// Note: convention in all put/take/etc is to preset
// local var holding count negative to indicate failure unless set.
// Note: convention in all put/take/etc is to preset local var
// holding count negative to indicate failure unless set.
int c = -1;
final ReentrantLock putLock = this.putLock;
final AtomicInteger count = this.count;
@ -273,18 +341,13 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
* not protected by lock. This works because count can
* only decrease at this point (all other puts are shut
* out by lock), and we (or some other waiting put) are
* signalled if it ever changes from
* capacity. Similarly for all other uses of count in
* other wait guards.
* signalled if it ever changes from capacity. Similarly
* for all other uses of count in other wait guards.
*/
try {
while (count.get() == capacity)
notFull.await();
} catch (InterruptedException ie) {
notFull.signal(); // propagate to a non-interrupted thread
throw ie;
while (count.get() == capacity) {
notFull.await();
}
insert(e);
enqueue(e);
c = count.getAndIncrement();
if (c + 1 < capacity)
notFull.signal();
@ -299,7 +362,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
* Inserts the specified element at the tail of this queue, waiting if
* necessary up to the specified wait time for space to become available.
*
* @return <tt>true</tt> if successful, or <tt>false</tt> if
* @return {@code true} if successful, or {@code false} if
* the specified waiting time elapses before space is available.
* @throws InterruptedException {@inheritDoc}
* @throws NullPointerException {@inheritDoc}
@ -314,23 +377,15 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
final AtomicInteger count = this.count;
putLock.lockInterruptibly();
try {
for (;;) {
if (count.get() < capacity) {
insert(e);
c = count.getAndIncrement();
if (c + 1 < capacity)
notFull.signal();
break;
}
while (count.get() == capacity) {
if (nanos <= 0)
return false;
try {
nanos = notFull.awaitNanos(nanos);
} catch (InterruptedException ie) {
notFull.signal(); // propagate to a non-interrupted thread
throw ie;
}
nanos = notFull.awaitNanos(nanos);
}
enqueue(e);
c = count.getAndIncrement();
if (c + 1 < capacity)
notFull.signal();
} finally {
putLock.unlock();
}
@ -342,7 +397,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
/**
* Inserts the specified element at the tail of this queue if it is
* possible to do so immediately without exceeding the queue's capacity,
* returning <tt>true</tt> upon success and <tt>false</tt> if this queue
* returning {@code true} upon success and {@code false} if this queue
* is full.
* When using a capacity-restricted queue, this method is generally
* preferable to method {@link BlockingQueue#add add}, which can fail to
@ -360,7 +415,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
putLock.lock();
try {
if (count.get() < capacity) {
insert(e);
enqueue(e);
c = count.getAndIncrement();
if (c + 1 < capacity)
notFull.signal();
@ -381,15 +436,10 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
final ReentrantLock takeLock = this.takeLock;
takeLock.lockInterruptibly();
try {
try {
while (count.get() == 0)
notEmpty.await();
} catch (InterruptedException ie) {
notEmpty.signal(); // propagate to a non-interrupted thread
throw ie;
while (count.get() == 0) {
notEmpty.await();
}
x = extract();
x = dequeue();
c = count.getAndDecrement();
if (c > 1)
notEmpty.signal();
@ -409,23 +459,15 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
final ReentrantLock takeLock = this.takeLock;
takeLock.lockInterruptibly();
try {
for (;;) {
if (count.get() > 0) {
x = extract();
c = count.getAndDecrement();
if (c > 1)
notEmpty.signal();
break;
}
while (count.get() == 0) {
if (nanos <= 0)
return null;
try {
nanos = notEmpty.awaitNanos(nanos);
} catch (InterruptedException ie) {
notEmpty.signal(); // propagate to a non-interrupted thread
throw ie;
}
nanos = notEmpty.awaitNanos(nanos);
}
x = dequeue();
c = count.getAndDecrement();
if (c > 1)
notEmpty.signal();
} finally {
takeLock.unlock();
}
@ -444,7 +486,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
takeLock.lock();
try {
if (count.get() > 0) {
x = extract();
x = dequeue();
c = count.getAndDecrement();
if (c > 1)
notEmpty.signal();
@ -457,7 +499,6 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
return x;
}
public E peek() {
if (count.get() == 0)
return null;
@ -474,44 +515,48 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
}
}
/**
* Unlinks interior Node p with predecessor trail.
*/
void unlink(Node<E> p, Node<E> trail) {
// assert isFullyLocked();
// p.next is not changed, to allow iterators that are
// traversing p to maintain their weak-consistency guarantee.
p.item = null;
trail.next = p.next;
if (last == p)
last = trail;
if (count.getAndDecrement() == capacity)
notFull.signal();
}
/**
* Removes a single instance of the specified element from this queue,
* if it is present. More formally, removes an element <tt>e</tt> such
* that <tt>o.equals(e)</tt>, if this queue contains one or more such
* if it is present. More formally, removes an element {@code e} such
* that {@code o.equals(e)}, if this queue contains one or more such
* elements.
* Returns <tt>true</tt> if this queue contained the specified element
* Returns {@code true} if this queue contained the specified element
* (or equivalently, if this queue changed as a result of the call).
*
* @param o element to be removed from this queue, if present
* @return <tt>true</tt> if this queue changed as a result of the call
* @return {@code true} if this queue changed as a result of the call
*/
public boolean remove(Object o) {
if (o == null) return false;
boolean removed = false;
fullyLock();
try {
Node<E> trail = head;
Node<E> p = head.next;
while (p != null) {
for (Node<E> trail = head, p = trail.next;
p != null;
trail = p, p = p.next) {
if (o.equals(p.item)) {
removed = true;
break;
unlink(p, trail);
return true;
}
trail = p;
p = p.next;
}
if (removed) {
p.item = null;
trail.next = p.next;
if (last == p)
last = trail;
if (count.getAndDecrement() == capacity)
notFull.signalAll();
}
return false;
} finally {
fullyUnlock();
}
return removed;
}
/**
@ -551,22 +596,22 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
* <p>If this queue fits in the specified array with room to spare
* (i.e., the array has more elements than this queue), the element in
* the array immediately following the end of the queue is set to
* <tt>null</tt>.
* {@code null}.
*
* <p>Like the {@link #toArray()} method, this method acts as bridge between
* array-based and collection-based APIs. Further, this method allows
* precise control over the runtime type of the output array, and may,
* under certain circumstances, be used to save allocation costs.
*
* <p>Suppose <tt>x</tt> is a queue known to contain only strings.
* <p>Suppose {@code x} is a queue known to contain only strings.
* The following code can be used to dump the queue into a newly
* allocated array of <tt>String</tt>:
* allocated array of {@code String}:
*
* <pre>
* String[] y = x.toArray(new String[0]);</pre>
*
* Note that <tt>toArray(new Object[0])</tt> is identical in function to
* <tt>toArray()</tt>.
* Note that {@code toArray(new Object[0])} is identical in function to
* {@code toArray()}.
*
* @param a the array into which the elements of the queue are to
* be stored, if it is big enough; otherwise, a new array of the
@ -577,6 +622,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
* this queue
* @throws NullPointerException if the specified array is null
*/
@SuppressWarnings("unchecked")
public <T> T[] toArray(T[] a) {
fullyLock();
try {
@ -586,7 +632,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
(a.getClass().getComponentType(), size);
int k = 0;
for (Node p = head.next; p != null; p = p.next)
for (Node<E> p = head.next; p != null; p = p.next)
a[k++] = (T)p.item;
if (a.length > k)
a[k] = null;
@ -612,11 +658,14 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
public void clear() {
fullyLock();
try {
head.next = null;
assert head.item == null;
last = head;
for (Node<E> p, h = head; (p = h.next) != null; h = p) {
h.next = h;
p.item = null;
}
head = last;
// assert head.item == null && head.next == null;
if (count.getAndSet(0) == capacity)
notFull.signalAll();
notFull.signal();
} finally {
fullyUnlock();
}
@ -629,30 +678,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
* @throws IllegalArgumentException {@inheritDoc}
*/
public int drainTo(Collection<? super E> c) {
if (c == null)
throw new NullPointerException();
if (c == this)
throw new IllegalArgumentException();
Node<E> first;
fullyLock();
try {
first = head.next;
head.next = null;
assert head.item == null;
last = head;
if (count.getAndSet(0) == capacity)
notFull.signalAll();
} finally {
fullyUnlock();
}
// Transfer the elements outside of locks
int n = 0;
for (Node<E> p = first; p != null; p = p.next) {
c.add(p.item);
p.item = null;
++n;
}
return n;
return drainTo(c, Integer.MAX_VALUE);
}
/**
@ -666,34 +692,44 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
throw new NullPointerException();
if (c == this)
throw new IllegalArgumentException();
fullyLock();
boolean signalNotFull = false;
final ReentrantLock takeLock = this.takeLock;
takeLock.lock();
try {
int n = 0;
Node<E> p = head.next;
while (p != null && n < maxElements) {
c.add(p.item);
p.item = null;
p = p.next;
++n;
int n = Math.min(maxElements, count.get());
// count.get provides visibility to first n Nodes
Node<E> h = head;
int i = 0;
try {
while (i < n) {
Node<E> p = h.next;
c.add(p.item);
p.item = null;
h.next = h;
h = p;
++i;
}
return n;
} finally {
// Restore invariants even if c.add() threw
if (i > 0) {
// assert h.item == null;
head = h;
signalNotFull = (count.getAndAdd(-i) == capacity);
}
}
if (n != 0) {
head.next = p;
assert head.item == null;
if (p == null)
last = head;
if (count.getAndAdd(-n) == capacity)
notFull.signalAll();
}
return n;
} finally {
fullyUnlock();
takeLock.unlock();
if (signalNotFull)
signalNotFull();
}
}
/**
* Returns an iterator over the elements in this queue in proper sequence.
* The returned <tt>Iterator</tt> is a "weakly consistent" iterator that
* will never throw {@link ConcurrentModificationException},
* The returned {@code Iterator} is a "weakly consistent" iterator that
* will never throw {@link java.util.ConcurrentModificationException
* ConcurrentModificationException},
* and guarantees to traverse elements as they existed upon
* construction of the iterator, and may (but is not guaranteed to)
* reflect any modifications subsequent to construction.
@ -706,7 +742,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
private class Itr implements Iterator<E> {
/*
* Basic weak-consistent iterator. At all times hold the next
* Basic weakly-consistent iterator. At all times hold the next
* item to hand out so that if hasNext() reports true, we will
* still have it to return even if lost race with a take etc.
*/
@ -715,17 +751,13 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
private E currentElement;
Itr() {
final ReentrantLock putLock = LinkedBlockingQueue.this.putLock;
final ReentrantLock takeLock = LinkedBlockingQueue.this.takeLock;
putLock.lock();
takeLock.lock();
fullyLock();
try {
current = head.next;
if (current != null)
currentElement = current.item;
} finally {
takeLock.unlock();
putLock.unlock();
fullyUnlock();
}
}
@ -733,54 +765,54 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
return current != null;
}
/**
* Unlike other traversal methods, iterators need to handle:
* - dequeued nodes (p.next == p)
* - interior removed nodes (p.item == null)
*/
private Node<E> nextNode(Node<E> p) {
Node<E> s = p.next;
if (p == s)
return head.next;
// Skip over removed nodes.
// May be necessary if multiple interior Nodes are removed.
while (s != null && s.item == null)
s = s.next;
return s;
}
public E next() {
final ReentrantLock putLock = LinkedBlockingQueue.this.putLock;
final ReentrantLock takeLock = LinkedBlockingQueue.this.takeLock;
putLock.lock();
takeLock.lock();
fullyLock();
try {
if (current == null)
throw new NoSuchElementException();
E x = currentElement;
lastRet = current;
current = current.next;
if (current != null)
currentElement = current.item;
current = nextNode(current);
currentElement = (current == null) ? null : current.item;
return x;
} finally {
takeLock.unlock();
putLock.unlock();
fullyUnlock();
}
}
public void remove() {
if (lastRet == null)
throw new IllegalStateException();
final ReentrantLock putLock = LinkedBlockingQueue.this.putLock;
final ReentrantLock takeLock = LinkedBlockingQueue.this.takeLock;
putLock.lock();
takeLock.lock();
fullyLock();
try {
Node<E> node = lastRet;
lastRet = null;
Node<E> trail = head;
Node<E> p = head.next;
while (p != null && p != node) {
trail = p;
p = p.next;
}
if (p == node) {
p.item = null;
trail.next = p.next;
if (last == p)
last = trail;
int c = count.getAndDecrement();
if (c == capacity)
notFull.signalAll();
for (Node<E> trail = head, p = trail.next;
p != null;
trail = p, p = p.next) {
if (p == node) {
unlink(p, trail);
break;
}
}
} finally {
takeLock.unlock();
putLock.unlock();
fullyUnlock();
}
}
}
@ -789,7 +821,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
* Save the state to a stream (that is, serialize it).
*
* @serialData The capacity is emitted (int), followed by all of
* its elements (each an <tt>Object</tt>) in the proper order,
* its elements (each an {@code Object}) in the proper order,
* followed by a null
* @param s the stream
*/
@ -815,6 +847,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
/**
* Reconstitute this queue instance from a stream (that is,
* deserialize it).
*
* @param s the stream
*/
private void readObject(java.io.ObjectInputStream s)
@ -827,6 +860,7 @@ public class LinkedBlockingQueue<E> extends AbstractQueue<E>
// Read in all elements and place in queue
for (;;) {
@SuppressWarnings("unchecked")
E item = (E)s.readObject();
if (item == null)
break;

14
jdk/src/solaris/native/java/lang/UNIXProcess_md.c
View File

@ -447,14 +447,16 @@ execve_with_shell_fallback(const char *file,
}
/**
* execvpe should have been included in the Unix standards.
* execvpe is identical to execvp, except that the child environment is
* 'execvpe' should have been included in the Unix standards,
* and is a GNU extension in glibc 2.10.
*
* JDK_execvpe is identical to execvp, except that the child environment is
* specified via the 3rd argument instead of being inherited from environ.
*/
static void
execvpe(const char *file,
const char *argv[],
const char *const envp[])
JDK_execvpe(const char *file,
const char *argv[],
const char *const envp[])
{
/* This is one of the rare times it's more portable to declare an
* external symbol explicitly, rather than via a system header.
@ -644,7 +646,7 @@ childProcess(void *arg)
if (fcntl(FAIL_FILENO, F_SETFD, FD_CLOEXEC) == -1)
goto WhyCantJohnnyExec;
execvpe(p->argv[0], p->argv, p->envv);
JDK_execvpe(p->argv[0], p->argv, p->envv);
WhyCantJohnnyExec:
/* We used to go to an awful lot of trouble to predict whether the

1
jdk/src/windows/classes/sun/nio/fs/WindowsConstants.java
View File

@ -92,6 +92,7 @@ class WindowsConstants {
public static final int ERROR_INVALID_DATA = 13;
public static final int ERROR_NOT_SAME_DEVICE = 17;
public static final int ERROR_NOT_READY = 21;
public static final int ERROR_SHARING_VIOLATION = 32;
public static final int ERROR_FILE_EXISTS = 80;
public static final int ERROR_INVALID_PARAMATER = 87;
public static final int ERROR_DISK_FULL = 112;

33
jdk/src/windows/classes/sun/nio/fs/WindowsFileAttributes.java
View File

@ -299,6 +299,9 @@ class WindowsFileAttributes
throws WindowsException
{
if (!ensureAccurateMetadata) {
WindowsException firstException = null;
// GetFileAttributesEx is the fastest way to read the attributes
NativeBuffer buffer =
NativeBuffers.getNativeBuffer(SIZEOF_FILE_ATTRIBUTE_DATA);
try {
@ -310,9 +313,39 @@ class WindowsFileAttributes
.getInt(address + OFFSETOF_FILE_ATTRIBUTE_DATA_ATTRIBUTES);
if ((fileAttrs & FILE_ATTRIBUTE_REPARSE_POINT) == 0)
return fromFileAttributeData(address, 0);
} catch (WindowsException x) {
if (x.lastError() != ERROR_SHARING_VIOLATION)
throw x;
firstException = x;
} finally {
buffer.release();
}
// For sharing violations, fallback to FindFirstFile if the file
// is not a root directory.
if (firstException != null) {
String search = path.getPathForWin32Calls();
char last = search.charAt(search.length() -1);
if (last == ':' || last == '\\')
throw firstException;
buffer = getBufferForFindData();
try {
long handle = FindFirstFile(search, buffer.address());
FindClose(handle);
WindowsFileAttributes attrs = fromFindData(buffer.address());
// FindFirstFile does not follow sym links. Even if
// followLinks is false, there isn't sufficient information
// in the WIN32_FIND_DATA structure to know if the reparse
// point is a sym link.
if (attrs.isReparsePoint())
throw firstException;
return attrs;
} catch (WindowsException ignore) {
throw firstException;
} finally {
buffer.release();
}
}
}
// file is reparse point so need to open file to get attributes

1
jdk/test/java/nio/channels/DatagramChannel/BasicMulticastTests.java
View File

@ -25,6 +25,7 @@
* @bug 4527345
* @summary Unit test for DatagramChannel's multicast support
* @build BasicMulticastTests NetworkConfiguration
* @run main BasicMulticastTests
*/
import java.nio.ByteBuffer;

1
jdk/test/java/nio/channels/DatagramChannel/MulticastSendReceiveTests.java
View File

@ -25,6 +25,7 @@
* @bug 4527345
* @summary Unit test for DatagramChannel's multicast support
* @build MulticastSendReceiveTests NetworkConfiguration
* @run main MulticastSendReceiveTests
*/
import java.nio.ByteBuffer;

1
jdk/test/java/nio/file/Files/ContentType.java
View File

@ -26,6 +26,7 @@
* @summary Unit test for probeContentType method
* @library ..
* @build ContentType SimpleFileTypeDetector
* @run main ContentType
*/
import java.nio.file.*;

24
jdk/test/java/nio/file/Path/Misc.java
View File

@ -22,7 +22,7 @@
*/
/* @test
* @bug 4313887 6838333
* @bug 4313887 6838333 6866804
* @summary Unit test for java.nio.file.Path for miscellenous methods not
* covered by other tests
* @library ..
@ -106,6 +106,28 @@ public class Misc {
dir.checkAccess(AccessMode.WRITE);
dir.checkAccess(AccessMode.READ, AccessMode.WRITE);
/**
* Test: Check access to all files in all root directories.
* (A useful test on Windows for special files such as pagefile.sys)
*/
for (Path root: FileSystems.getDefault().getRootDirectories()) {
DirectoryStream<Path> stream;
try {
stream = root.newDirectoryStream();
} catch (IOException x) {
continue; // skip root directories that aren't accessible
}
try {
for (Path entry: stream) {
try {
entry.checkAccess();
} catch (AccessDeniedException ignore) { }
}
} finally {
stream.close();
}
}
/**
* Test: File does not exist
*/

35
jdk/test/java/util/Collection/MOAT.java
View File

@ -426,6 +426,36 @@ public class MOAT {
q.poll();
equal(q.size(), 4);
checkFunctionalInvariants(q);
if ((q instanceof LinkedBlockingQueue) ||
(q instanceof LinkedBlockingDeque) ||
(q instanceof ConcurrentLinkedQueue)) {
testQueueIteratorRemove(q);
}
}
private static void testQueueIteratorRemove(Queue<Integer> q) {
System.err.printf("testQueueIteratorRemove %s%n",
q.getClass().getSimpleName());
q.clear();
for (int i = 0; i < 5; i++)
q.add(i);
Iterator<Integer> it = q.iterator();
check(it.hasNext());
for (int i = 3; i >= 0; i--)
q.remove(i);
equal(it.next(), 0);
equal(it.next(), 4);
q.clear();
for (int i = 0; i < 5; i++)
q.add(i);
it = q.iterator();
equal(it.next(), 0);
check(it.hasNext());
for (int i = 1; i < 4; i++)
q.remove(i);
equal(it.next(), 1);
equal(it.next(), 4);
}
private static void testList(final List<Integer> l) {
@ -451,6 +481,11 @@ public class MOAT {
}
private static void testCollection(Collection<Integer> c) {
try { testCollection1(c); }
catch (Throwable t) { unexpected(t); }
}
private static void testCollection1(Collection<Integer> c) {
System.out.println("\n==> " + c.getClass().getName());

4
jdk/test/java/util/Formatter/Basic-X.java
View File

@ -486,6 +486,10 @@ public class Basic$Type$ extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

2
jdk/test/java/util/Formatter/Basic.java
View File

@ -25,7 +25,7 @@
* @summary Unit test for formatter
* @bug 4906370 4962433 4973103 4989961 5005818 5031150 4970931 4989491 5002937
* 5005104 5007745 5061412 5055180 5066788 5088703 6317248 6318369 6320122
* 6344623 6369500 6534606 6282094 6286592 6476425
* 6344623 6369500 6534606 6282094 6286592 6476425 5063507
*
* @run shell/timeout=240 Basic.sh
*/

4
jdk/test/java/util/Formatter/BasicBigDecimal.java
View File

@ -486,6 +486,10 @@ public class BasicBigDecimal extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicBigInteger.java
View File

@ -486,6 +486,10 @@ public class BasicBigInteger extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicBoolean.java
View File

@ -486,6 +486,10 @@ public class BasicBoolean extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicBooleanObject.java
View File

@ -486,6 +486,10 @@ public class BasicBooleanObject extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicByte.java
View File

@ -486,6 +486,10 @@ public class BasicByte extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicByteObject.java
View File

@ -486,6 +486,10 @@ public class BasicByteObject extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicChar.java
View File

@ -486,6 +486,10 @@ public class BasicChar extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicCharObject.java
View File

@ -486,6 +486,10 @@ public class BasicCharObject extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicDateTime.java
View File

@ -486,6 +486,10 @@ public class BasicDateTime extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicDouble.java
View File

@ -486,6 +486,10 @@ public class BasicDouble extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicDoubleObject.java
View File

@ -486,6 +486,10 @@ public class BasicDoubleObject extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicFloat.java
View File

@ -486,6 +486,10 @@ public class BasicFloat extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicFloatObject.java
View File

@ -486,6 +486,10 @@ public class BasicFloatObject extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicInt.java
View File

@ -486,6 +486,10 @@ public class BasicInt extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicIntObject.java
View File

@ -486,6 +486,10 @@ public class BasicIntObject extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicLong.java
View File

@ -486,6 +486,10 @@ public class BasicLong extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicLongObject.java
View File

@ -486,6 +486,10 @@ public class BasicLongObject extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicShort.java
View File

@ -486,6 +486,10 @@ public class BasicShort extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

4
jdk/test/java/util/Formatter/BasicShortObject.java
View File

@ -486,6 +486,10 @@ public class BasicShortObject extends Basic {
//---------------------------------------------------------------------
tryCatch("%-s", MissingFormatWidthException.class);
tryCatch("%--s", DuplicateFormatFlagsException.class);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, 0.5f);
tryCatch("%#s", FormatFlagsConversionMismatchException.class, "hello");
tryCatch("%#s", FormatFlagsConversionMismatchException.class, null);
//---------------------------------------------------------------------
// %h

142
jdk/test/java/util/TimSort/ArrayBuilder.java Normal file
View File

@ -0,0 +1,142 @@
/*
* Copyright 2009 Google Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
import java.util.Random;
import java.math.BigInteger;
public enum ArrayBuilder {
// These seven are from Tim's paper (listsort.txt)
RANDOM_INT {
public Object[] build(int len) {
Integer[] result = new Integer[len];
for (int i = 0; i < len; i++)
result[i] = rnd.nextInt();
return result;
}
},
DESCENDING_INT {
public Object[] build(int len) {
Integer[] result = new Integer[len];
for (int i = 0; i < len; i++)
result[i] = len - i;
return result;
}
},
ASCENDING_INT {
public Object[] build(int len) {
Integer[] result = new Integer[len];
for (int i = 0; i < len; i++)
result[i] = i;
return result;
}
},
ASCENDING_3_RND_EXCH_INT {
public Object[] build(int len) {
Integer[] result = new Integer[len];
for (int i = 0; i < len; i++)
result[i] = i;
for (int i = 0; i < 3; i++)
swap(result, rnd.nextInt(result.length),
rnd.nextInt(result.length));
return result;
}
},
ASCENDING_10_RND_AT_END_INT {
public Object[] build(int len) {
Integer[] result = new Integer[len];
int endStart = len - 10;
for (int i = 0; i < endStart; i++)
result[i] = i;
for (int i = endStart; i < len; i++)
result[i] = rnd.nextInt(endStart + 10);
return result;
}
},
ALL_EQUAL_INT {
public Object[] build(int len) {
Integer[] result = new Integer[len];
for (int i = 0; i < len; i++)
result[i] = 666;
return result;
}
},
DUPS_GALORE_INT {
public Object[] build(int len) {
Integer[] result = new Integer[len];
for (int i = 0; i < len; i++)
result[i] = rnd.nextInt(4);
return result;
}
},
RANDOM_WITH_DUPS_INT {
public Object[] build(int len) {
Integer[] result = new Integer[len];
for (int i = 0; i < len; i++)
result[i] = rnd.nextInt(len);
return result;
}
},
PSEUDO_ASCENDING_STRING {
public String[] build(int len) {
String[] result = new String[len];
for (int i = 0; i < len; i++)
result[i] = Integer.toString(i);
return result;
}
},
RANDOM_BIGINT {
public BigInteger[] build(int len) {
BigInteger[] result = new BigInteger[len];
for (int i = 0; i < len; i++)
result[i] = HUGE.add(BigInteger.valueOf(rnd.nextInt(len)));
return result;
}
};
public abstract Object[] build(int len);
public void resetRandom() {
rnd = new Random(666);
}
private static Random rnd = new Random(666);
private static void swap(Object[] a, int i, int j) {
Object t = a[i];
a[i] = a[j];
a[j] = t;
}
private static BigInteger HUGE = BigInteger.ONE.shiftLeft(100);
}

4
jdk/test/java/util/TimSort/README Normal file
View File

@ -0,0 +1,4 @@
This directory contains benchmark programs used to compare the
performance of the TimSort algorithm against the historic 1997
implementation of Arrays.sort. Any future benchmarking will require
minor modifications.

66
jdk/test/java/util/TimSort/SortPerf.java Normal file
View File

@ -0,0 +1,66 @@
/*
* Copyright 2009 Google Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
import java.util.Arrays;
public class SortPerf {
private static final int NUM_SETS = 5;
private static final int[] lengths = { 10, 100, 1000, 10000, 1000000 };
// Returns the number of repetitions as a function of the list length
private static int reps(int n) {
return (int) (12000000 / (n * Math.log10(n)));
}
public static void main(String[] args) {
Sorter.warmup();
System.out.print("Strategy,Length");
for (Sorter sorter : Sorter.values())
System.out.print("," + sorter);
System.out.println();
for (ArrayBuilder ab : ArrayBuilder.values()) {
for (int n : lengths) {
System.out.printf("%s,%d", ab, n);
int reps = reps(n);
Object[] proto = ab.build(n);
for (Sorter sorter : Sorter.values()) {
double minTime = Double.POSITIVE_INFINITY;
for (int set = 0; set < NUM_SETS; set++) {
long startTime = System.nanoTime();
for (int k = 0; k < reps; k++) {
Object[] a = proto.clone();
sorter.sort(a);
}
long endTime = System.nanoTime();
double time = (endTime - startTime) / (1000000. * reps);
minTime = Math.min(minTime, time);
}
System.out.printf(",%5f", minTime);
}
System.out.println();
}
}
}
}

55
jdk/test/java/util/TimSort/Sorter.java Normal file
View File

@ -0,0 +1,55 @@
/*
* Copyright 2009 Google Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
import java.util.*;
public enum Sorter {
TIMSORT {
public void sort(Object[] array) {
ComparableTimSort.sort(array);
}
},
MERGESORT {
public void sort(Object[] array) {
Arrays.sort(array);
}
};
public abstract void sort(Object[] array);
public static void warmup() {
System.out.println("start warm up");
Integer[] gold = new Integer[10000];
Random random = new java.util.Random();
for (int i=0; i < gold.length; i++)
gold[i] = random.nextInt();
for (int i=0; i < 10000; i++) {
for (Sorter s : values()) {
Integer[] test= gold.clone();
s.sort(test);
}
}
System.out.println(" end warm up");
}
}

130
jdk/test/java/util/concurrent/BlockingQueue/OfferDrainToLoops.java Normal file
View File

@ -0,0 +1,130 @@
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/licenses/publicdomain
*/
/*
* @test
* @bug 6805775 6815766
* @summary Test concurrent offer vs. drainTo
*/
import java.util.*;
import java.util.concurrent.*;
@SuppressWarnings({"unchecked", "rawtypes"})
public class OfferDrainToLoops {
void checkNotContainsNull(Iterable it) {
for (Object x : it)
check(x != null);
}
abstract class CheckedThread extends Thread {
abstract protected void realRun();
public void run() {
try { realRun(); } catch (Throwable t) { unexpected(t); }
}
{
setDaemon(true);
start();
}
}
void test(String[] args) throws Throwable {
test(new LinkedBlockingQueue());
test(new LinkedBlockingQueue(2000));
test(new LinkedBlockingDeque());
test(new LinkedBlockingDeque(2000));
test(new ArrayBlockingQueue(2000));
}
void test(final BlockingQueue q) throws Throwable {
System.out.println(q.getClass().getSimpleName());
final long testDurationSeconds = 1L;
final long testDurationMillis = testDurationSeconds * 1000L;
final long quittingTimeNanos
= System.nanoTime() + testDurationSeconds * 1000L * 1000L * 1000L;
Thread offerer = new CheckedThread() {
protected void realRun() {
for (long i = 0; ; i++) {
if ((i % 1024) == 0 &&
System.nanoTime() - quittingTimeNanos > 0)
break;
while (! q.offer(i))
Thread.yield();
}}};
Thread drainer = new CheckedThread() {
protected void realRun() {
for (long i = 0; ; i++) {
if (System.nanoTime() - quittingTimeNanos > 0)
break;
List list = new ArrayList();
int n = q.drainTo(list);
equal(list.size(), n);
for (int j = 0; j < n - 1; j++)
equal((Long) list.get(j) + 1L, list.get(j + 1));
Thread.yield();
}}};
Thread scanner = new CheckedThread() {
protected void realRun() {
for (long i = 0; ; i++) {
if (System.nanoTime() - quittingTimeNanos > 0)
break;
checkNotContainsNull(q);
Thread.yield();
}}};
offerer.join(10 * testDurationMillis);
drainer.join(10 * testDurationMillis);
check(! offerer.isAlive());
check(! drainer.isAlive());
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
new OfferDrainToLoops().instanceMain(args);}
public void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
}

98
jdk/test/java/util/concurrent/ConcurrentLinkedQueue/ConcurrentQueueLoops.java → jdk/test/java/util/concurrent/ConcurrentQueues/ConcurrentQueueLoops.java
View File

@ -33,9 +33,8 @@
/*
* @test
* @bug 4486658
* @compile -source 1.5 ConcurrentQueueLoops.java
* @run main/timeout=230 ConcurrentQueueLoops
* @bug 4486658 6785442
* @run main ConcurrentQueueLoops 8 123456
* @summary Checks that a set of threads can repeatedly get and modify items
*/
@ -44,34 +43,75 @@ import java.util.concurrent.*;
import java.util.concurrent.atomic.*;
public class ConcurrentQueueLoops {
static final ExecutorService pool = Executors.newCachedThreadPool();
static AtomicInteger totalItems;
static boolean print = false;
ExecutorService pool;
AtomicInteger totalItems;
boolean print;
public static void main(String[] args) throws Exception {
int maxStages = 8;
int items = 100000;
// Suitable for benchmarking. Overriden by args[0] for testing.
int maxStages = 20;
// Suitable for benchmarking. Overriden by args[1] for testing.
int items = 1024 * 1024;
Collection<Queue<Integer>> concurrentQueues() {
List<Queue<Integer>> queues = new ArrayList<Queue<Integer>>();
queues.add(new ConcurrentLinkedQueue<Integer>());
queues.add(new ArrayBlockingQueue<Integer>(items, false));
//queues.add(new ArrayBlockingQueue<Integer>(count, true));
queues.add(new LinkedBlockingQueue<Integer>());
queues.add(new LinkedBlockingDeque<Integer>());
try {
queues.add((Queue<Integer>)
Class.forName("java.util.concurrent.LinkedTransferQueue")
.newInstance());
} catch (IllegalAccessException e) {
} catch (InstantiationException e) {
} catch (ClassNotFoundException e) {
// OK; not yet added to JDK
}
// Following additional implementations are available from:
// http://gee.cs.oswego.edu/dl/concurrency-interest/index.html
// queues.add(new LinkedTransferQueue<Integer>());
// queues.add(new SynchronizedLinkedListQueue<Integer>());
// Avoid "first fast, second slow" benchmark effect.
Collections.shuffle(queues);
return queues;
}
void test(String[] args) throws Throwable {
if (args.length > 0)
maxStages = Integer.parseInt(args[0]);
if (args.length > 1)
items = Integer.parseInt(args[1]);
for (Queue<Integer> queue : concurrentQueues())
test(queue);
}
void test(final Queue<Integer> q) throws Throwable {
System.out.println(q.getClass().getSimpleName());
pool = Executors.newCachedThreadPool();
print = false;
print = false;
System.out.println("Warmup...");
oneRun(1, items);
Thread.sleep(100);
oneRun(1, items);
oneRun(1, items, q);
//Thread.sleep(100);
oneRun(3, items, q);
Thread.sleep(100);
print = true;
for (int i = 1; i <= maxStages; i += (i+1) >>> 1) {
oneRun(i, items);
oneRun(i, items, q);
}
pool.shutdown();
if (! pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS))
throw new Error();
check(pool.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS));
}
static class Stage implements Callable<Integer> {
class Stage implements Callable<Integer> {
final Queue<Integer> queue;
final CyclicBarrier barrier;
int items;
@ -110,15 +150,11 @@ public class ConcurrentQueueLoops {
}
return new Integer(l);
}
catch (Exception ie) {
ie.printStackTrace();
throw new Error("Call loop failed");
}
catch (Throwable t) { unexpected(t); return null; }
}
}
static void oneRun(int n, int items) throws Exception {
Queue<Integer> q = new ConcurrentLinkedQueue<Integer>();
void oneRun(int n, int items, final Queue<Integer> q) throws Exception {
LoopHelpers.BarrierTimer timer = new LoopHelpers.BarrierTimer();
CyclicBarrier barrier = new CyclicBarrier(n + 1, timer);
totalItems = new AtomicInteger(n * items);
@ -141,6 +177,22 @@ public class ConcurrentQueueLoops {
System.out.println(LoopHelpers.rightJustify(time / (items * n)) + " ns per item");
if (total == 0) // avoid overoptimization
System.out.println("useless result: " + total);
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
new ConcurrentQueueLoops().instanceMain(args);}
public void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
}

165
jdk/test/java/util/concurrent/ConcurrentQueues/GCRetention.java Normal file
View File

@ -0,0 +1,165 @@
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/licenses/publicdomain
*/
/*
* @test
* @bug 6785442
* @summary Benchmark that tries to GC-tenure head, followed by
* many add/remove operations.
* @run main GCRetention 12345
*/
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.PriorityBlockingQueue;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Queue;
import java.util.Map;
public class GCRetention {
// Suitable for benchmarking. Overriden by args[0] for testing.
int count = 1024 * 1024;
final Map<String,String> results = new ConcurrentHashMap<String,String>();
Collection<Queue<Boolean>> queues() {
List<Queue<Boolean>> queues = new ArrayList<Queue<Boolean>>();
queues.add(new ConcurrentLinkedQueue<Boolean>());
queues.add(new ArrayBlockingQueue<Boolean>(count, false));
queues.add(new ArrayBlockingQueue<Boolean>(count, true));
queues.add(new LinkedBlockingQueue<Boolean>());
queues.add(new LinkedBlockingDeque<Boolean>());
queues.add(new PriorityBlockingQueue<Boolean>());
queues.add(new PriorityQueue<Boolean>());
queues.add(new LinkedList<Boolean>());
try {
queues.add((Queue<Boolean>)
Class.forName("java.util.concurrent.LinkedTransferQueue")
.newInstance());
} catch (IllegalAccessException e) {
} catch (InstantiationException e) {
} catch (ClassNotFoundException e) {
// OK; not yet added to JDK
}
// Following additional implementations are available from:
// http://gee.cs.oswego.edu/dl/concurrency-interest/index.html
// queues.add(new LinkedTransferQueue<Boolean>());
// queues.add(new SynchronizedLinkedListQueue<Boolean>());
// Avoid "first fast, second slow" benchmark effect.
Collections.shuffle(queues);
return queues;
}
void prettyPrintResults() {
List<String> classNames = new ArrayList<String>(results.keySet());
Collections.sort(classNames);
int maxClassNameLength = 0;
int maxNanosLength = 0;
for (String name : classNames) {
if (maxClassNameLength < name.length())
maxClassNameLength = name.length();
if (maxNanosLength < results.get(name).length())
maxNanosLength = results.get(name).length();
}
String format = String.format("%%%ds %%%ds nanos/item%%n",
maxClassNameLength, maxNanosLength);
for (String name : classNames)
System.out.printf(format, name, results.get(name));
}
void test(String[] args) {
if (args.length > 0)
count = Integer.valueOf(args[0]);
// Warmup
for (Queue<Boolean> queue : queues())
test(queue);
results.clear();
for (Queue<Boolean> queue : queues())
test(queue);
prettyPrintResults();
}
void test(Queue<Boolean> q) {
long t0 = System.nanoTime();
for (int i = 0; i < count; i++)
check(q.add(Boolean.TRUE));
System.gc();
System.gc();
Boolean x;
while ((x = q.poll()) != null)
equal(x, Boolean.TRUE);
check(q.isEmpty());
for (int i = 0; i < 10 * count; i++) {
for (int k = 0; k < 3; k++)
check(q.add(Boolean.TRUE));
for (int k = 0; k < 3; k++)
if (q.poll() != Boolean.TRUE)
fail();
}
check(q.isEmpty());
String className = q.getClass().getSimpleName();
long elapsed = System.nanoTime() - t0;
int nanos = (int) ((double) elapsed / (10 * 3 * count));
results.put(className, String.valueOf(nanos));
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
new GCRetention().instanceMain(args);}
public void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
}

93
jdk/test/java/util/concurrent/ConcurrentQueues/IteratorWeakConsistency.java Normal file
View File

@ -0,0 +1,93 @@
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/licenses/publicdomain
*/
import java.util.*;
import java.util.concurrent.*;
/*
* @test
* @bug 6805775 6815766
* @summary Check weak consistency of concurrent queue iterators
*/
@SuppressWarnings({"unchecked", "rawtypes"})
public class IteratorWeakConsistency {
void test(String[] args) throws Throwable {
test(new LinkedBlockingQueue());
test(new LinkedBlockingQueue(20));
test(new LinkedBlockingDeque());
test(new LinkedBlockingDeque(20));
test(new ConcurrentLinkedQueue());
// Other concurrent queues (e.g. ArrayBlockingQueue) do not
// currently have weakly consistent iterators.
// test(new ArrayBlockingQueue(20));
}
void test(Queue q) throws Throwable {
// TODO: make this more general
for (int i = 0; i < 10; i++)
q.add(i);
Iterator it = q.iterator();
q.poll();
q.poll();
q.poll();
q.remove(7);
List list = new ArrayList();
while (it.hasNext())
list.add(it.next());
equal(list, Arrays.asList(0, 3, 4, 5, 6, 8, 9));
check(! list.contains(null));
System.out.printf("%s: %s%n",
q.getClass().getSimpleName(),
list);
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
static Class<?> thisClass = new Object(){}.getClass().getEnclosingClass();
public static void main(String[] args) throws Throwable {
new IteratorWeakConsistency().instanceMain(args);}
public void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
}

0
jdk/test/java/util/concurrent/ConcurrentLinkedQueue/LoopHelpers.java → jdk/test/java/util/concurrent/ConcurrentQueues/LoopHelpers.java
View File

230
jdk/test/java/util/concurrent/ConcurrentQueues/RemovePollRace.java Normal file
View File

@ -0,0 +1,230 @@
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*/
/*
* This file is available under and governed by the GNU General Public
* License version 2 only, as published by the Free Software Foundation.
* However, the following notice accompanied the original version of this
* file:
*
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/licenses/publicdomain
*/
/*
* @test
* @bug 6785442
* @summary Checks race between poll and remove(Object), while
* occasionally moonlighting as a microbenchmark.
* @run main RemovePollRace 12345
*/
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.LinkedBlockingQueue;
import java.util.concurrent.atomic.AtomicLong;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Queue;
import java.util.Map;
public class RemovePollRace {
// Suitable for benchmarking. Overriden by args[0] for testing.
int count = 1024 * 1024;
final Map<String,String> results = new ConcurrentHashMap<String,String>();
Collection<Queue<Boolean>> concurrentQueues() {
List<Queue<Boolean>> queues = new ArrayList<Queue<Boolean>>();
queues.add(new ConcurrentLinkedQueue<Boolean>());
queues.add(new ArrayBlockingQueue<Boolean>(count, false));
queues.add(new ArrayBlockingQueue<Boolean>(count, true));
queues.add(new LinkedBlockingQueue<Boolean>());
queues.add(new LinkedBlockingDeque<Boolean>());
try {
queues.add((Queue<Boolean>)
Class.forName("java.util.concurrent.LinkedTransferQueue")
.newInstance());
} catch (IllegalAccessException e) {
} catch (InstantiationException e) {
} catch (ClassNotFoundException e) {
// OK; not yet added to JDK
}
// Following additional implementations are available from:
// http://gee.cs.oswego.edu/dl/concurrency-interest/index.html
// queues.add(new LinkedTransferQueue<Boolean>());
// queues.add(new SynchronizedLinkedListQueue<Boolean>());
// Avoid "first fast, second slow" benchmark effect.
Collections.shuffle(queues);
return queues;
}
void prettyPrintResults() {
List<String> classNames = new ArrayList<String>(results.keySet());
Collections.sort(classNames);
int maxClassNameLength = 0;
int maxNanosLength = 0;
for (String name : classNames) {
if (maxClassNameLength < name.length())
maxClassNameLength = name.length();
if (maxNanosLength < results.get(name).length())
maxNanosLength = results.get(name).length();
}
String format = String.format("%%%ds %%%ds nanos/item%%n",
maxClassNameLength, maxNanosLength);
for (String name : classNames)
System.out.printf(format, name, results.get(name));
}
void test(String[] args) throws Throwable {
if (args.length > 0)
count = Integer.valueOf(args[0]);
// Warmup
for (Queue<Boolean> queue : concurrentQueues())
test(queue);
results.clear();
for (Queue<Boolean> queue : concurrentQueues())
test(queue);
prettyPrintResults();
}
void await(CountDownLatch latch) {
try { latch.await(); }
catch (InterruptedException e) { unexpected(e); }
}
void test(final Queue<Boolean> q) throws Throwable {
long t0 = System.nanoTime();
final int SPINS = 5;
final AtomicLong removes = new AtomicLong(0);
final AtomicLong polls = new AtomicLong(0);
final int adderCount =
Math.max(1, Runtime.getRuntime().availableProcessors() / 4);
final int removerCount =
Math.max(1, Runtime.getRuntime().availableProcessors() / 4);
final int pollerCount = removerCount;
final int threadCount = adderCount + removerCount + pollerCount;
final CountDownLatch startingGate = new CountDownLatch(1);
final CountDownLatch addersDone = new CountDownLatch(adderCount);
final Runnable remover = new Runnable() {
public void run() {
await(startingGate);
int spins = 0;
for (;;) {
boolean quittingTime = (addersDone.getCount() == 0);
if (q.remove(Boolean.TRUE))
removes.getAndIncrement();
else if (quittingTime)
break;
else if (++spins > SPINS) {
Thread.yield();
spins = 0;
}}}};
final Runnable poller = new Runnable() {
public void run() {
await(startingGate);
int spins = 0;
for (;;) {
boolean quittingTime = (addersDone.getCount() == 0);
if (q.poll() == Boolean.TRUE)
polls.getAndIncrement();
else if (quittingTime)
break;
else if (++spins > SPINS) {
Thread.yield();
spins = 0;
}}}};
final Runnable adder = new Runnable() {
public void run() {
await(startingGate);
for (int i = 0; i < count; i++) {
for (;;) {
try { q.add(Boolean.TRUE); break; }
catch (IllegalStateException e) { Thread.yield(); }
}
}
addersDone.countDown();
}};
final List<Thread> adders = new ArrayList<Thread>();
final List<Thread> removers = new ArrayList<Thread>();
final List<Thread> pollers = new ArrayList<Thread>();
for (int i = 0; i < adderCount; i++)
adders.add(checkedThread(adder));
for (int i = 0; i < removerCount; i++)
removers.add(checkedThread(remover));
for (int i = 0; i < pollerCount; i++)
pollers.add(checkedThread(poller));
final List<Thread> allThreads = new ArrayList<Thread>();
allThreads.addAll(removers);
allThreads.addAll(pollers);
allThreads.addAll(adders);
for (Thread t : allThreads)
t.start();
startingGate.countDown();
for (Thread t : allThreads)
t.join();
String className = q.getClass().getSimpleName();
long elapsed = System.nanoTime() - t0;
int nanos = (int) ((double) elapsed / (adderCount * count));
results.put(className, String.valueOf(nanos));
if (removes.get() + polls.get() != adderCount * count) {
String msg = String.format
("class=%s removes=%s polls=%d count=%d",
className, removes.get(), polls.get(), count);
fail(msg);
}
}
//--------------------- Infrastructure ---------------------------
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
new RemovePollRace().instanceMain(args);}
public void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new AssertionError("Some tests failed");}
Thread checkedThread(final Runnable r) {
return new Thread() {public void run() {
try {r.run();} catch (Throwable t) {unexpected(t);}}};}
}

74
jdk/test/java/util/concurrent/LinkedBlockingQueue/OfferRemoveLoops.java
View File

@ -28,62 +28,74 @@
* @author Martin Buchholz
*/
import java.util.*;
import java.util.concurrent.*;
public class OfferRemoveLoops {
private static void realMain(String[] args) throws Throwable {
void test(String[] args) throws Throwable {
testQueue(new LinkedBlockingQueue<String>(10));
testQueue(new LinkedBlockingQueue<String>());
testQueue(new LinkedBlockingDeque<String>(10));
testQueue(new LinkedBlockingDeque<String>());
testQueue(new ArrayBlockingQueue<String>(10));
testQueue(new PriorityBlockingQueue<String>(10));
testQueue(new ConcurrentLinkedQueue<String>());
}
private abstract static class ControlledThread extends Thread {
abstract class CheckedThread extends Thread {
abstract protected void realRun();
public void run() {
try { realRun(); } catch (Throwable t) { unexpected(t); }
}
}
private static void testQueue(final BlockingQueue<String> q) throws Throwable {
System.out.println(q.getClass());
final int count = 10000;
final long quittingTime = System.nanoTime() + 1L * 1000L * 1000L * 1000L;
Thread t1 = new ControlledThread() {
protected void realRun() {
for (int i = 0, j = 0; i < count; i++)
while (! q.remove(String.valueOf(i))
&& System.nanoTime() - quittingTime < 0)
Thread.yield();}};
Thread t2 = new ControlledThread() {
protected void realRun() {
for (int i = 0, j = 0; i < count; i++)
while (! q.offer(String.valueOf(i))
&& System.nanoTime() - quittingTime < 0)
Thread.yield();}};
void testQueue(final Queue<String> q) throws Throwable {
System.out.println(q.getClass().getSimpleName());
final int count = 1000 * 1000;
final long testDurationSeconds = 1L;
final long testDurationMillis = testDurationSeconds * 1000L;
final long quittingTimeNanos
= System.nanoTime() + testDurationSeconds * 1000L * 1000L * 1000L;
Thread t1 = new CheckedThread() {
protected void realRun() {
for (int i = 0; i < count; i++) {
if ((i % 1024) == 0 &&
System.nanoTime() - quittingTimeNanos > 0)
return;
while (! q.remove(String.valueOf(i)))
Thread.yield();
}}};
Thread t2 = new CheckedThread() {
protected void realRun() {
for (int i = 0; i < count; i++) {
if ((i % 1024) == 0 &&
System.nanoTime() - quittingTimeNanos > 0)
return;
while (! q.offer(String.valueOf(i)))
Thread.yield();
}}};
t1.setDaemon(true); t2.setDaemon(true);
t1.start(); t2.start();
t1.join(10000); t2.join(10000);
t1.join(10 * testDurationMillis);
t2.join(10 * testDurationMillis);
check(! t1.isAlive());
check(! t2.isAlive());
}
//--------------------- Infrastructure ---------------------------
static volatile int passed = 0, failed = 0;
static void pass() { passed++; }
static void fail() { failed++; Thread.dumpStack(); }
static void unexpected(Throwable t) { failed++; t.printStackTrace(); }
static void check(boolean cond) { if (cond) pass(); else fail(); }
static void equal(Object x, Object y) {
volatile int passed = 0, failed = 0;
void pass() {passed++;}
void fail() {failed++; Thread.dumpStack();}
void fail(String msg) {System.err.println(msg); fail();}
void unexpected(Throwable t) {failed++; t.printStackTrace();}
void check(boolean cond) {if (cond) pass(); else fail();}
void equal(Object x, Object y) {
if (x == null ? y == null : x.equals(y)) pass();
else {System.out.println(x + " not equal to " + y); fail(); }}
else fail(x + " not equal to " + y);}
public static void main(String[] args) throws Throwable {
try { realMain(args); } catch (Throwable t) { unexpected(t); }
new OfferRemoveLoops().instanceMain(args);}
public void instanceMain(String[] args) throws Throwable {
try {test(args);} catch (Throwable t) {unexpected(t);}
System.out.printf("%nPassed = %d, failed = %d%n%n", passed, failed);
if (failed > 0) throw new Exception("Some tests failed");
}
if (failed > 0) throw new AssertionError("Some tests failed");}
}

2
jdk/test/sun/security/krb5/ConfPlusProp.java
View File

@ -23,7 +23,7 @@
/*
* @test
* @bug 6857795
* @buf 6858589
* @bug 6858589
* @summary krb5.conf ignored if system properties on realm and kdc are provided
*/