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8027348: (process) Enhancement of handling async close of ProcessInputStream

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Reviewed-by: martin
This commit is contained in:
Ivan Gerasimov 2014-01-30 00:02:46 +04:00
parent 49605b7bf9
commit 592907e7f2
4 changed files with 176 additions and 198 deletions
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44
jdk/src/solaris/classes/java/lang/UNIXProcess.java.bsd
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@ -342,47 +342,39 @@ final class UNIXProcess extends Process {
ProcessPipeInputStream(int fd) {
super(new FileInputStream(newFileDescriptor(fd)));
}
private InputStream drainInputStream(InputStream in)
private static byte[] drainInputStream(InputStream in)
throws IOException {
int n = 0;
int j;
byte[] a = null;
synchronized (closeLock) {
if (buf == null) // asynchronous close()?
return null; // discard
j = in.available();
}
while (j > 0) {
while ((j = in.available()) > 0) {
a = (a == null) ? new byte[j] : Arrays.copyOf(a, n + j);
synchronized (closeLock) {
if (buf == null) // asynchronous close()?
return null; // discard
n += in.read(a, n, j);
j = in.available();
}
n += in.read(a, n, j);
}
return (a == null) ?
ProcessBuilder.NullInputStream.INSTANCE :
new ByteArrayInputStream(n == a.length ? a : Arrays.copyOf(a, n));
return (a == null || n == a.length) ? a : Arrays.copyOf(a, n);
}
/** Called by the process reaper thread when the process exits. */
synchronized void processExited() {
try {
InputStream in = this.in;
if (in != null) {
InputStream stragglers = drainInputStream(in);
in.close();
this.in = stragglers;
}
} catch (IOException ignored) { }
synchronized (closeLock) {
try {
InputStream in = this.in;
// this stream is closed if and only if: in == null
if (in != null) {
byte[] stragglers = drainInputStream(in);
in.close();
this.in = (stragglers == null) ?
ProcessBuilder.NullInputStream.INSTANCE :
new ByteArrayInputStream(stragglers);
}
} catch (IOException ignored) {}
}
}
@Override
public void close() throws IOException {
// BufferedInputStream#close() is not synchronized unlike most other methods.
// Synchronizing helps avoid racing with drainInputStream().
// Synchronizing helps avoid race with processExited().
synchronized (closeLock) {
super.close();
}

44
jdk/src/solaris/classes/java/lang/UNIXProcess.java.linux
View File

@ -344,47 +344,39 @@ final class UNIXProcess extends Process {
ProcessPipeInputStream(int fd) {
super(new FileInputStream(newFileDescriptor(fd)));
}
private InputStream drainInputStream(InputStream in)
private static byte[] drainInputStream(InputStream in)
throws IOException {
int n = 0;
int j;
byte[] a = null;
synchronized (closeLock) {
if (buf == null) // asynchronous close()?
return null; // discard
j = in.available();
}
while (j > 0) {
while ((j = in.available()) > 0) {
a = (a == null) ? new byte[j] : Arrays.copyOf(a, n + j);
synchronized (closeLock) {
if (buf == null) // asynchronous close()?
return null; // discard
n += in.read(a, n, j);
j = in.available();
}
n += in.read(a, n, j);
}
return (a == null) ?
ProcessBuilder.NullInputStream.INSTANCE :
new ByteArrayInputStream(n == a.length ? a : Arrays.copyOf(a, n));
return (a == null || n == a.length) ? a : Arrays.copyOf(a, n);
}
/** Called by the process reaper thread when the process exits. */
synchronized void processExited() {
try {
InputStream in = this.in;
if (in != null) {
InputStream stragglers = drainInputStream(in);
in.close();
this.in = stragglers;
}
} catch (IOException ignored) { }
synchronized (closeLock) {
try {
InputStream in = this.in;
// this stream is closed if and only if: in == null
if (in != null) {
byte[] stragglers = drainInputStream(in);
in.close();
this.in = (stragglers == null) ?
ProcessBuilder.NullInputStream.INSTANCE :
new ByteArrayInputStream(stragglers);
}
} catch (IOException ignored) {}
}
}
@Override
public void close() throws IOException {
// BufferedInputStream#close() is not synchronized unlike most other methods.
// Synchronizing helps avoid racing with drainInputStream().
// Synchronizing helps avoid race with processExited().
synchronized (closeLock) {
super.close();
}

140
jdk/test/java/lang/ProcessBuilder/CloseRace.java Normal file
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@ -0,0 +1,140 @@
/*
* Copyright (c) 2013, 2014 Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* @test
* @bug 8024521
* @summary Closing ProcessPipeInputStream at the time the process exits is racy
* and leads to data corruption. Run this test manually (as
* an ordinary java program) with -Xmx8M to repro bug 8024521.
* @run main/othervm -Xmx8M -Dtest.duration=2 CloseRace
*/
import java.io.*;
import java.util.ArrayList;
import java.util.List;
public class CloseRace {
private static final String BIG_FILE = "bigfile";
private static final int[] procFDs = new int[6];
/** default value sufficient to repro bug 8024521. */
private static final int testDurationSeconds
= Integer.getInteger("test.duration", 600);
static boolean fdInUse(int i) {
return new File("/proc/self/fd/" + i).exists();
}
static boolean[] procFDsInUse() {
boolean[] inUse = new boolean[procFDs.length];
for (int i = 0; i < procFDs.length; i++)
inUse[i] = fdInUse(procFDs[i]);
return inUse;
}
static int count(boolean[] bits) {
int count = 0;
for (int i = 0; i < bits.length; i++)
count += bits[i] ? 1 : 0;
return count;
}
public static void main(String args[]) throws Exception {
if (!(new File("/proc/self/fd").isDirectory()))
return;
// Catch Errors from process reaper
Thread.setDefaultUncaughtExceptionHandler
((t, e) -> { e.printStackTrace(); System.exit(1); });
try (RandomAccessFile f = new RandomAccessFile(BIG_FILE, "rw")) {
f.setLength(Runtime.getRuntime().maxMemory()); // provoke OOME
}
for (int i = 0, j = 0; j < procFDs.length; i++)
if (!fdInUse(i))
procFDs[j++] = i;
Thread[] threads = {
new Thread(new OpenLoop()),
new Thread(new ExecLoop()),
};
for (Thread thread : threads)
thread.start();
Thread.sleep(testDurationSeconds * 1000);
for (Thread thread : threads)
thread.interrupt();
for (Thread thread : threads)
thread.join();
}
static class OpenLoop implements Runnable {
public void run() {
while (!Thread.interrupted()) {
try {
// wait for ExecLoop to finish creating process
do {} while (count(procFDsInUse()) != 3);
List<InputStream> iss = new ArrayList<>(4);
// eat up three "holes" (closed ends of pipe fd pairs)
for (int i = 0; i < 3; i++)
iss.add(new FileInputStream(BIG_FILE));
do {} while (count(procFDsInUse()) == procFDs.length);
// hopefully this will racily occupy empty fd slot
iss.add(new FileInputStream(BIG_FILE));
Thread.sleep(1); // Widen race window
for (InputStream is : iss)
is.close();
} catch (InterruptedException e) {
break;
} catch (Exception e) {
throw new Error(e);
}
}
}
}
static class ExecLoop implements Runnable {
public void run() {
ProcessBuilder builder = new ProcessBuilder("/bin/true");
while (!Thread.interrupted()) {
try {
// wait for OpenLoop to finish
do {} while (count(procFDsInUse()) > 0);
Process process = builder.start();
InputStream is = process.getInputStream();
process.waitFor();
is.close();
} catch (InterruptedException e) {
break;
} catch (Exception e) {
throw new Error(e);
}
}
}
}
}

146
jdk/test/java/lang/Runtime/exec/CloseRace.java
View File

@ -1,146 +0,0 @@
/*
* Copyright (c) 2013, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
/**
* @test
* @bug 8024521
* @summary Closing ProcessPipeInputStream at the time the process exits is racy
* and leads to the data corruption.
* @library /lib/testlibrary
* @run main/othervm/timeout=80 CloseRace
*/
/**
* This test has a little chance to catch the race during the given default
* time gap of 20 seconds. To increase the time gap, set the system property
* CloseRaceTimeGap=N to the number of seconds.
* Jtreg's timeoutFactor should also be set appropriately.
*
* For example, to run the test for 10 minutes:
* > jtreg \
* -testjdk:$(PATH_TO_TESTED_JDK) \
* -timeoutFactor:10 \
* -DCloseRaceTimeGap=600 \
* $(PATH_TO_TESTED_JDK_SOURCE)/test/java/lang/Runtime/exec/CloseRace.java
*/
import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import jdk.testlibrary.OutputAnalyzer;
import static jdk.testlibrary.ProcessTools.*;
public class CloseRace {
public static void main(String args[]) throws Exception {
ProcessBuilder pb = createJavaProcessBuilder("-Xmx64M", "CloseRace$Child",
System.getProperty("CloseRaceTimeGap", "20"));
OutputAnalyzer oa = new OutputAnalyzer(pb.start());
oa.stderrShouldNotContain("java.lang.OutOfMemoryError");
}
public static class Child {
private static final String BIG_FILE = "bigfile";
private static final String SMALL_FILE = "smallfile";
private static int timeGap = 20; // seconds
public static void main(String args[]) throws Exception {
if (args.length > 0) {
try {
timeGap = Integer.parseUnsignedInt(args[0]);
timeGap = Integer.max(timeGap, 10);
timeGap = Integer.min(timeGap, 10 * 60 * 60); // no more than 10 hours
} catch (NumberFormatException ignore) {}
}
try (RandomAccessFile f = new RandomAccessFile(BIG_FILE, "rw")) {
f.setLength(1024 * 1024 * 1024); // 1 Gb, greater than max heap size
}
try (FileOutputStream fs = new FileOutputStream(SMALL_FILE);
PrintStream ps = new PrintStream(fs)) {
for (int i = 0; i < 128; ++i)
ps.println("line of text");
}
List<Thread> threads = new LinkedList<>();
for (int i = 0; i < 99; ++i) {
Thread t = new Thread (new OpenLoop());
t.start();
threads.add(t);
}
Thread t2 = new Thread (new ExecLoop());
t2.start();
threads.add(t2);
Thread.sleep(timeGap);
for (Thread t : threads) {
t.interrupt();
t.join();
}
}
private static class OpenLoop implements Runnable {
public void run() {
final Path bigFilePath = Paths.get(BIG_FILE);
while (!Thread.interrupted()) {
try (InputStream in = Files.newInputStream(bigFilePath)) {
// Widen the race window by sleeping 1ms
Thread.sleep(1);
} catch (InterruptedException e) {
break;
} catch (Exception e) {
System.err.println(e);
}
}
}
}
private static class ExecLoop implements Runnable {
public void run() {
List<String> command = new ArrayList<>(
Arrays.asList("/bin/cat", SMALL_FILE));
while (!Thread.interrupted()) {
try {
ProcessBuilder builder = new ProcessBuilder(command);
final Process process = builder.start();
InputStream is = process.getInputStream();
InputStreamReader isr = new InputStreamReader(is);
BufferedReader br = new BufferedReader(isr);
while (br.readLine() != null) {}
process.waitFor();
isr.close();
} catch (InterruptedException e) {
break;
} catch (Exception e) {
System.err.println(e);
}
}
}
}
}
}