8173898: StackWalker.walk throws InternalError if called from a constructor invoked through reflection

StackWalker is fixed to take into account constructor reflection frames. The specification of StackWalker.Option.SHOW_REFLECT_FRAMES is also clarified in this regard.

Reviewed-by: bchristi, lancea, mchung, psandoz
This commit is contained in:
Daniel Fuchs 2017-02-08 16:33:52 +00:00
parent 35bad958c1
commit fcc0a083e4
4 changed files with 930 additions and 18 deletions

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@ -25,11 +25,13 @@
package java.lang;
import jdk.internal.reflect.MethodAccessor;
import jdk.internal.reflect.ConstructorAccessor;
import java.lang.StackWalker.Option;
import java.lang.StackWalker.StackFrame;
import java.lang.annotation.Native;
import java.lang.reflect.Method;
import java.lang.reflect.Constructor;
import java.util.HashSet;
import java.util.NoSuchElementException;
import java.util.Objects;
@ -922,7 +924,8 @@ final class StackStreamFactory {
*/
final void setBatch(int depth, int startIndex, int endIndex) {
if (startIndex <= 0 || endIndex <= 0)
throw new IllegalArgumentException("startIndex=" + startIndex + " endIndex=" + endIndex);
throw new IllegalArgumentException("startIndex=" + startIndex
+ " endIndex=" + endIndex);
this.origin = startIndex;
this.fence = endIndex;
@ -980,13 +983,18 @@ final class StackStreamFactory {
private static boolean isReflectionFrame(Class<?> c) {
if (c.getName().startsWith("jdk.internal.reflect") &&
!MethodAccessor.class.isAssignableFrom(c)) {
throw new InternalError("Not jdk.internal.reflect.MethodAccessor: " + c.toString());
!MethodAccessor.class.isAssignableFrom(c) &&
!ConstructorAccessor.class.isAssignableFrom(c)) {
throw new InternalError("Not jdk.internal.reflect.MethodAccessor"
+ " or jdk.internal.reflect.ConstructorAccessor: "
+ c.toString());
}
// ## should filter all @Hidden frames?
return c == Method.class ||
MethodAccessor.class.isAssignableFrom(c) ||
c.getName().startsWith("java.lang.invoke.LambdaForm");
c == Constructor.class ||
MethodAccessor.class.isAssignableFrom(c) ||
ConstructorAccessor.class.isAssignableFrom(c) ||
c.getName().startsWith("java.lang.invoke.LambdaForm");
}
}

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@ -29,6 +29,7 @@ import jdk.internal.reflect.CallerSensitive;
import java.util.*;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Predicate;
import java.util.stream.Stream;
/**
@ -207,13 +208,23 @@ public final class StackWalker {
/**
* Shows all reflection frames.
*
* <p>By default, reflection frames are hidden. This includes the
* {@link java.lang.reflect.Method#invoke} method
* and the reflection implementation classes. A {@code StackWalker} with
* this {@code SHOW_REFLECT_FRAMES} option will show all reflection frames.
* The {@link #SHOW_HIDDEN_FRAMES} option can also be used to show all
* <p>By default, reflection frames are hidden. A {@code StackWalker}
* configured with this {@code SHOW_REFLECT_FRAMES} option
* will show all reflection frames that
* include {@link java.lang.reflect.Method#invoke} and
* {@link java.lang.reflect.Constructor#newInstance(Object...)}
* and their reflection implementation classes.
*
* <p>The {@link #SHOW_HIDDEN_FRAMES} option can also be used to show all
* reflection frames and it will also show other hidden frames that
* are implementation-specific.
*
* @apiNote
* This option includes the stack frames representing the invocation of
* {@code Method} and {@code Constructor}. Any utility methods that
* are equivalent to calling {@code Method.invoke} or
* {@code Constructor.newInstance} such as {@code Class.newInstance}
* are not filtered or controlled by any stack walking option.
*/
SHOW_REFLECT_FRAMES,
/**
@ -468,8 +479,9 @@ public final class StackWalker {
* Gets the {@code Class} object of the caller invoking the method
* that calls this {@code getCallerClass} method.
*
* <p> Reflection frames, {@link java.lang.invoke.MethodHandle}, and
* hidden frames are filtered regardless of the
* <p> This method filters {@linkplain Option#SHOW_REFLECT_FRAMES reflection
* frames}, {@link java.lang.invoke.MethodHandle}, and
* {@linkplain Option#SHOW_HIDDEN_FRAMES hidden frames} regardless of the
* {@link Option#SHOW_REFLECT_FRAMES SHOW_REFLECT_FRAMES}
* and {@link Option#SHOW_HIDDEN_FRAMES SHOW_HIDDEN_FRAMES} options
* this {@code StackWalker} has been configured with.

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@ -23,18 +23,21 @@
/*
* @test
* @bug 8140450
* @bug 8140450 8173898
* @summary Basic test for the StackWalker::walk method
* @run testng Basic
*/
import java.lang.StackWalker.StackFrame;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import static java.lang.StackWalker.Option.*;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;
import static org.testng.Assert.*;
public class Basic {
private static boolean verbose = false;
@ -60,6 +63,17 @@ public class Basic {
}
}
@Test
public static void testWalkFromConstructor() throws Exception {
System.out.println("testWalkFromConstructor:");
List<String> found = ((ConstructorNewInstance)ConstructorNewInstance.class.getMethod("create")
.invoke(null)).collectedFrames();
assertEquals(List.of(ConstructorNewInstance.class.getName()+"::<init>",
ConstructorNewInstance.class.getName()+"::create",
Basic.class.getName()+"::testWalkFromConstructor"),
found);
}
private final int depth;
Basic(int depth) {
this.depth = depth;
@ -77,6 +91,47 @@ public class Basic {
assertEquals(limit, frames.size());
}
static class ConstructorNewInstance {
static final StackWalker walker =
StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE);
List<String> testFramesOrReflectionFrames;
public ConstructorNewInstance() {
testFramesOrReflectionFrames = walker.walk(this::parse);
}
public List<String> collectedFrames() {
return testFramesOrReflectionFrames;
}
public boolean accept(StackFrame f) {
// Frames whose class names don't contain "."
// are our own test frames. These are the ones
// we expect.
// Frames whose class names contain ".reflect."
// are reflection frames. None should be present,
// since they are supposed to be filtered by
// by StackWalker. If we find any, we want to fail.
if (!f.getClassName().contains(".")
|| f.getClassName().contains(".reflect.")) {
System.out.println(" " + f);
return true;
}
// Filter out all other frames (in particular
// those from the test framework) in order to
// have predictable results.
return false;
}
public String frame(StackFrame f) {
return f.getClassName() + "::" + f.getMethodName();
}
List<String> parse(Stream<StackFrame> s) {
return s.filter(this::accept)
.map(this::frame)
.collect(Collectors.toList());
}
public static ConstructorNewInstance create() throws Exception {
return ConstructorNewInstance.class.getConstructor().newInstance();
}
}
class StackBuilder {
private final int stackDepth;
private final int limit;
@ -131,9 +186,4 @@ public class Basic {
}
}
static void assertEquals(int x, int y) {
if (x != y) {
throw new RuntimeException(x + " != " + y);
}
}
}

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@ -0,0 +1,842 @@
/*
* Copyright (c) 2017, 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 8173898
* @summary Basic test for checking filtering of reflection frames
* @run testng ReflectionFrames
*/
import java.lang.StackWalker.StackFrame;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.lang.invoke.MethodHandle;
import java.lang.invoke.MethodHandles;
import java.lang.invoke.MethodHandles.Lookup;
import java.lang.invoke.MethodType;
import java.util.EnumSet;
import java.util.List;
import java.util.function.Supplier;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import static java.lang.StackWalker.Option.*;
import org.testng.annotations.DataProvider;
import org.testng.annotations.Test;
import static org.testng.Assert.*;
public class ReflectionFrames {
final static boolean verbose = false;
/**
* This test invokes new StackInspector() directly from
* the caller StackInspector.Caller.create method.
* It checks that the caller is StackInspector.Caller.
* It also checks the expected frames collected
* by walking the stack from the default StackInspector()
* constructor.
* This is done twice, once using a default StackWalker
* that hides reflection frames, once using a StackWalker
* configured to show reflection frames.
*/
@Test
public static void testNewStackInspector() throws Exception {
// Sets the default walker which hides reflection
// frames.
StackInspector.walker.set(StackInspector.walkerHide);
// Calls the StackInspector.create method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The create method invokes new StackInspector() directly.
// No reflection frame should appear.
System.out.println("testNewStackInspector: create");
StackInspector obj = ((StackInspector)StackInspector.Caller.class
.getMethod("create", How.class)
.invoke(null, How.NEW));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
ReflectionFrames.class.getName()
+"::testNewStackInspector"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertEquals(obj.filtered, 0);
// Calls the StackInspector.reflect method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The reflect method invokes the create method through
// reflection.
// The create method invokes new StackInspector() directly.
// No reflection frame should appear.
System.out.println("testNewStackInspector: reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("reflect", How.class)
.invoke(null, How.NEW));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
StackInspector.Caller.class.getName()
+"::reflect",
ReflectionFrames.class.getName()
+"::testNewStackInspector"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertEquals(obj.filtered, 0);
// Calls the StackInspector.handle method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The handle method invokes the create method using
// a MethodHandle.
// The create method invokes new StackInspector() directly.
// No reflection frame should appear.
System.out.println("testNewStackInspector: handle");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("handle", How.class)
.invoke(null, How.NEW));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
StackInspector.Caller.class.getName()
+"::handle",
ReflectionFrames.class.getName()
+"::testNewStackInspector"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertEquals(obj.filtered, 0);
// Sets a non-default walker configured to show
// reflection frames
StackInspector.walker.set(StackInspector.walkerShow);
// Calls the StackInspector.create method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The create method invokes new StackInspector() directly.
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testNewStackInspector: create: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("create", How.class)
.invoke(null, How.NEW));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testNewStackInspector"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertNotEquals(obj.filtered, 0);
// Calls the StackInspector.reflect method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The reflect method invokes the create method through
// reflection.
// The create method invokes new StackInspector() directly.
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testNewStackInspector: reflect: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("reflect", How.class)
.invoke(null, How.NEW));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
Method.class.getName()
+"::invoke",
StackInspector.Caller.class.getName()
+"::reflect",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testNewStackInspector"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertNotEquals(obj.filtered, 0);
// Calls the StackInspector.handle method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The handle method invokes the create method using
// MethodHandle.
// The create method invokes new StackInspector() directly.
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testNewStackInspector: handle: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("handle", How.class)
.invoke(null, How.NEW));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
// MethodHandle::invoke remains hidden
StackInspector.Caller.class.getName()
+"::handle",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testNewStackInspector"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertNotEquals(obj.filtered, 0);
}
/**
* This test invokes Constructor.newInstance() from
* the caller StackInspector.Caller.create method.
* It checks that the caller is StackInspector.Caller.
* It also checks the expected frames collected
* by walking the stack from the default StackInspector()
* constructor.
* This is done twice, once using a default StackWalker
* that hides reflection frames, once using a StackWalker
* configured to show reflection frames.
*/
@Test
public static void testConstructor() throws Exception {
// Sets the default walker which hides reflection
// frames.
StackInspector.walker.set(StackInspector.walkerHide);
// Calls the StackInspector.create method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The create method invokes Constructor.newInstance().
// No reflection frame should appear.
System.out.println("testConstructor: create");
StackInspector obj = ((StackInspector)StackInspector.Caller.class
.getMethod("create", How.class)
.invoke(null, How.CONSTRUCTOR));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
ReflectionFrames.class.getName()
+"::testConstructor"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertEquals(obj.filtered, 0);
// Calls the StackInspector.reflect method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The reflect method invokes the create method through
// reflection.
// The create method invokes Constructor.newInstance().
// No reflection frame should appear.
System.out.println("testConstructor: reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("reflect", How.class)
.invoke(null, How.CONSTRUCTOR));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
StackInspector.Caller.class.getName()
+"::reflect",
ReflectionFrames.class.getName()
+"::testConstructor"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertEquals(obj.filtered, 0);
// Calls the StackInspector.handle method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The handle method invokes the create method using
// MethodHandle.
// The create method invokes Constructor.newInstance().
// No reflection frame should appear.
System.out.println("testConstructor: handle");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("handle", How.class)
.invoke(null, How.CONSTRUCTOR));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
StackInspector.Caller.class.getName()
+"::create",
StackInspector.Caller.class.getName()
+"::handle",
ReflectionFrames.class.getName()
+"::testConstructor"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertEquals(obj.filtered, 0);
// Sets a non-default walker configured to show
// reflection frames
StackInspector.walker.set(StackInspector.walkerShow);
// Calls the StackInspector.create method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The create method invokes Constructor.newInstance().
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testConstructor: create: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("create", How.class)
.invoke(null, How.CONSTRUCTOR));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Constructor.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testConstructor"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertNotEquals(obj.filtered, 0);
// Calls the StackInspector.reflect method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The reflect method invokes the create method through
// reflection.
// The create method invokes Constructor.newInstance().
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testConstructor: reflect: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("reflect", How.class)
.invoke(null, How.CONSTRUCTOR));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Constructor.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
Method.class.getName()
+"::invoke",
StackInspector.Caller.class.getName()
+"::reflect",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testConstructor"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertNotEquals(obj.filtered, 0);
// Calls the StackInspector.handle method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The handle method invokes the create method using
// MethodHandle.
// The create method invokes Constructor.newInstance().
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testConstructor: handle: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("handle", How.class)
.invoke(null, How.CONSTRUCTOR));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Constructor.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
// MethodHandle::invoke remains hidden
StackInspector.Caller.class.getName()
+"::handle",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testConstructor"));
assertEquals(obj.cls, StackInspector.Caller.class);
assertNotEquals(obj.filtered, 0);
}
/**
* This test invokes StackInspector.class.newInstance() from
* the caller StackInspector.Caller.create method. Because
* Class.newInstance() is not considered as a
* reflection frame, the the caller returned by
* getCallerClass() should appear to be java.lang.Class
* and not StackInspector.Caller.
* It also checks the expected frames collected
* by walking the stack from the default StackInspector()
* constructor.
* This is done twice, once using a default StackWalker
* that hides reflection frames, once using a StackWalker
* configured to show reflection frames.
*/
@Test
public static void testNewInstance() throws Exception {
// Sets the default walker which hides reflection
// frames.
StackInspector.walker.set(StackInspector.walkerHide);
// Calls the StackInspector.create method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The create method invokes StackInspector.class.newInstance().
// No reflection frame should appear, except
// Class::newInstance which is not considered as
// a reflection frame.
System.out.println("testNewInstance: create");
StackInspector obj = ((StackInspector)StackInspector.Caller.class
.getMethod("create", How.class)
.invoke(null, How.CLASS));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Class.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
ReflectionFrames.class.getName()
+"::testNewInstance"));
// Because Class.newInstance is not filtered, then the
// caller is Class.class
assertEquals(obj.cls, Class.class);
assertEquals(obj.filtered, 0);
// Calls the StackInspector.reflect method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The reflect method invokes the create method through
// reflection.
// The create method invokes StackInspector.class.newInstance().
// No reflection frame should appear, except
// Class::newInstance which is not considered as
// a reflection frame.
System.out.println("testNewInstance: reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("reflect", How.class)
.invoke(null, How.CLASS));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Class.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
StackInspector.Caller.class.getName()
+"::reflect",
ReflectionFrames.class.getName()
+"::testNewInstance"));
// Because Class.newInstance is not filtered, then the
// caller is Class.class
assertEquals(obj.cls, Class.class);
assertEquals(obj.filtered, 0);
// Calls the StackInspector.handle method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The handle method invokes the create method using
// reflection.
// The create method invokes StackInspector.class.newInstance().
// No reflection frame should appear, except
// Class::newInstance which is not considered as
// a reflection frame.
System.out.println("testNewInstance: handle");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("handle", How.class)
.invoke(null, How.CLASS));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Class.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
StackInspector.Caller.class.getName()
+"::handle",
ReflectionFrames.class.getName()
+"::testNewInstance"));
// Because Class.newInstance is not filtered, then the
// caller is Class.class
assertEquals(obj.cls, Class.class);
assertEquals(obj.filtered, 0);
// Sets a non-default walker configured to show
// reflection frames
StackInspector.walker.set(StackInspector.walkerShow);
// Calls the StackInspector.create method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The create method invokes StackInspector.class.newInstance().
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testNewInstance: create: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("create", How.class)
.invoke(null, How.CLASS));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Constructor.class.getName()
+"::newInstance",
Class.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testNewInstance"));
// Because Class.newInstance is not filtered, then the
// caller is Class.class
assertEquals(obj.cls, Class.class);
assertNotEquals(obj.filtered, 0);
// Calls the StackInspector.reflect method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The reflect method invokes the create method through
// reflection.
// The create method invokes StackInspector.class.newInstance().
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testNewInstance: reflect: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("reflect", How.class)
.invoke(null, How.CLASS));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Constructor.class.getName()
+"::newInstance",
Class.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
Method.class.getName()
+"::invoke",
StackInspector.Caller.class.getName()
+"::reflect",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testNewInstance"));
// Because Class.newInstance is not filtered, then the
// caller is Class.class
assertEquals(obj.cls, Class.class);
assertNotEquals(obj.filtered, 0);
// Calls the StackInspector.handle method through reflection
// and check the frames collected in the StackInspector
// default constructor.
// The handle method invokes the create method using
// MethodHandle.
// The create method invokes StackInspector.class.newInstance().
// We should see all reflection frames, except the
// jdk.internal.reflect frames which we are filtering
// out in StackInspector::filter.
System.out.println("testNewInstance: handle: show reflect");
obj = ((StackInspector)StackInspector.Caller.class
.getMethod("handle", How.class)
.invoke(null, How.CLASS));
assertEquals(obj.collectedFrames,
List.of(StackInspector.class.getName()
+"::<init>",
Constructor.class.getName()
+"::newInstance",
Class.class.getName()
+"::newInstance",
StackInspector.Caller.class.getName()
+"::create",
// MethodHandle::invoke remains hidden
StackInspector.Caller.class.getName()
+"::handle",
Method.class.getName()
+"::invoke",
ReflectionFrames.class.getName()
+"::testNewInstance"));
// Because Class.newInstance is not filtered, then the
// caller is Class.class
assertEquals(obj.cls, Class.class);
assertNotEquals(obj.filtered, 0);
}
@Test
public static void testGetCaller() throws Exception {
// Sets the default walker which hides reflection
// frames.
StackInspector.walker.set(StackInspector.walkerHide);
assertEquals(StackInspector.getCaller(), ReflectionFrames.class);
assertEquals(StackInspector.class.getMethod("getCaller").invoke(null),
ReflectionFrames.class);
// Sets a non-default walker configured to show
// reflection frames
StackInspector.walker.set(StackInspector.walkerShow);
assertEquals(StackInspector.getCaller(), ReflectionFrames.class);
assertEquals(StackInspector.class.getMethod("getCaller").invoke(null),
ReflectionFrames.class);
}
@Test
public static void testReflectCaller() throws Exception {
// Sets the default walker which hides reflection
// frames.
StackInspector.walker.set(StackInspector.walkerHide);
assertEquals(StackInspector.reflectCaller(), ReflectionFrames.class);
assertEquals(StackInspector.class.getMethod("reflectCaller").invoke(null),
ReflectionFrames.class);
// Sets a non-default walker configured to show
// reflection frames
StackInspector.walker.set(StackInspector.walkerShow);
assertEquals(StackInspector.reflectCaller(), ReflectionFrames.class);
assertEquals(StackInspector.class.getMethod("reflectCaller").invoke(null),
ReflectionFrames.class);
}
@Test
public static void testSupplyCaller() throws Exception {
// Sets the default walker which hides reflection
// frames.
StackInspector.walker.set(StackInspector.walkerHide);
assertEquals(StackInspector.supplyCaller(), ReflectionFrames.class);
assertEquals(StackInspector.class.getMethod("supplyCaller").invoke(null),
ReflectionFrames.class);
// Sets a non-default walker configured to show
// reflection frames
StackInspector.walker.set(StackInspector.walkerShow);
assertEquals(StackInspector.supplyCaller(), ReflectionFrames.class);
assertEquals(StackInspector.class.getMethod("supplyCaller").invoke(null),
ReflectionFrames.class);
}
@Test
public static void testHandleCaller() throws Exception {
// Sets the default walker which hides reflection
// frames.
StackInspector.walker.set(StackInspector.walkerHide);
assertEquals(StackInspector.handleCaller(), ReflectionFrames.class);
assertEquals(StackInspector.class.getMethod("handleCaller").invoke(null),
ReflectionFrames.class);
// Sets a non-default walker configured to show
// reflection frames
StackInspector.walker.set(StackInspector.walkerShow);
assertEquals(StackInspector.handleCaller(), ReflectionFrames.class);
assertEquals(StackInspector.class.getMethod("handleCaller").invoke(null),
ReflectionFrames.class);
}
static enum How { NEW, CONSTRUCTOR, CLASS};
/**
* An object that collect stack frames by walking the stack
* (and calling getCallerClass()) from within its constructor.
* For the purpose of this test, StackInspector objects are
* always created from the nested StackInspector.Caller class,
* which should therefore appear as the caller of the
* StackInspector constructor.
*/
static class StackInspector {
static final StackWalker walkerHide =
StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE);
static final StackWalker walkerShow =
StackWalker.getInstance(EnumSet.of(
StackWalker.Option.RETAIN_CLASS_REFERENCE,
StackWalker.Option.SHOW_REFLECT_FRAMES));
final static ThreadLocal<StackWalker> walker = new ThreadLocal<>() {
protected StackWalker initialValue() {
return walkerHide;
}
};
List<String> collectedFrames;
Class<?> cls = null;
boolean stop;
int filtered;
final boolean filterImplFrames;
public StackInspector() {
stop = false;
// if reflection frames are not hidden, we want to
// filter implementation frames before collecting
// to avoid depending on internal details.
filterImplFrames = walker.get() == walkerShow;
collectedFrames = walker.get().walk(this::parse);
cls = walker.get().getCallerClass();
}
public List<String> collectedFrames() {
return collectedFrames;
}
// The takeWhile method arrange for stopping frame collection
// as soon as a frame from ReflectionFrames.class is reached.
// The first such frame encountered is still included in the
// collected frames, but collection stops right after.
// This makes it possible to filter out anything above the
// the test method frame, such as frames from the test
// framework.
public boolean takeWhile(StackFrame f) {
if (stop) return false;
if (verbose) System.out.println(" " + f);
stop = stop || f.getDeclaringClass() == ReflectionFrames.class;
return true;
}
// filter out implementation frames to avoid depending
// on implementation details. If present, Class::newInstance,
// Method::invoke and Constructor::newInstance will
// still appear in the collected frames, which is
// sufficient for the purpose of the test.
// In the case where the StackWalker itself is supposed to
// filter the reflection frames, then this filter will always
// return true. This way, if such a reflection frame appears when
// it sjould have been filtered by StackWalker, it will make the
// test fail.
public boolean filter(StackFrame f) {
if (filterImplFrames &&
f.getClassName().startsWith("jdk.internal.reflect.")) {
filtered++;
return false;
}
if (!verbose) System.out.println(" " + f);
return true;
}
public String frame(StackFrame f) {
return f.getClassName() + "::" + f.getMethodName();
}
List<String> parse(Stream<StackFrame> s) {
return s.takeWhile(this::takeWhile)
.filter(this::filter)
.map(this::frame)
.collect(Collectors.toList());
}
/**
* The Caller class is used to create instances of
* StackInspector, either direcltly, or throug reflection.
*/
public static class Caller {
public static StackInspector create(How how) throws Exception {
switch(how) {
case NEW: return new StackInspector();
case CONSTRUCTOR: return StackInspector.class
.getConstructor().newInstance();
case CLASS: return StackInspector.class.newInstance();
default: throw new AssertionError(String.valueOf(how));
}
}
public static StackInspector reflect(How how) throws Exception {
return (StackInspector) Caller.class.getMethod("create", How.class)
.invoke(null, how);
}
public static StackInspector handle(How how) throws Exception {
Lookup lookup = MethodHandles.lookup();
MethodHandle mh = lookup.findStatic(Caller.class, "create",
MethodType.methodType(StackInspector.class, How.class));
try {
return (StackInspector) mh.invoke(how);
} catch (Error | Exception x) {
throw x;
} catch(Throwable t) {
throw new AssertionError(t);
}
}
}
public static Class<?> getCaller() throws Exception {
return walker.get().getCallerClass();
}
public static Class<?> reflectCaller() throws Exception {
return (Class<?>)StackWalker.class.getMethod("getCallerClass")
.invoke(walker.get());
}
public static Class<?> supplyCaller() throws Exception {
return ((Supplier<Class<?>>)StackInspector.walker.get()::getCallerClass).get();
}
public static Class<?> handleCaller() throws Exception {
Lookup lookup = MethodHandles.lookup();
MethodHandle mh = lookup.findVirtual(StackWalker.class, "getCallerClass",
MethodType.methodType(Class.class));
try {
return (Class<?>) mh.invoke(walker.get());
} catch (Error | Exception x) {
throw x;
} catch(Throwable t) {
throw new AssertionError(t);
}
}
}
}