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8065991: LogManager unecessarily calls JavaAWTAccess from within a critical section

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The call to JavaAWTAccess is moved outside of the critical section

Reviewed-by: mchung
This commit is contained in:
Daniel Fuchs 2014-12-05 12:20:51 +01:00
parent 765c10de6e
commit 7e7e10eb42
2 changed files with 375 additions and 5 deletions
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10
jdk/src/java.logging/share/classes/java/util/logging/LogManager.java
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@ -458,11 +458,11 @@ public class LogManager {
JavaAWTAccess javaAwtAccess = SharedSecrets.getJavaAWTAccess();
if (sm != null && javaAwtAccess != null) {
// for each applet, it has its own LoggerContext isolated from others
synchronized (javaAwtAccess) {
// find the AppContext of the applet code
// will be null if we are in the main app context.
final Object ecx = javaAwtAccess.getAppletContext();
if (ecx != null) {
final Object ecx = javaAwtAccess.getAppletContext();
if (ecx != null) {
synchronized (javaAwtAccess) {
// find the AppContext of the applet code
// will be null if we are in the main app context.
if (contextsMap == null) {
contextsMap = new WeakHashMap<>();
}

370
jdk/test/java/util/logging/LogManagerAppContextDeadlock.java Normal file
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@ -0,0 +1,370 @@
/*
* 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.
*/
import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.security.CodeSource;
import java.security.Permission;
import java.security.PermissionCollection;
import java.security.Permissions;
import java.security.Policy;
import java.security.ProtectionDomain;
import java.util.Enumeration;
import java.util.concurrent.Semaphore;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.LogManager;
import java.util.logging.Logger;
/**
* @test
* @bug 8065991
* @summary check that when LogManager is initialized, a deadlock similar
* to that described in 8065709 will not occur.
* @run main/othervm LogManagerAppContextDeadlock UNSECURE
* @run main/othervm LogManagerAppContextDeadlock SECURE
*
* @author danielfuchs
*/
public class LogManagerAppContextDeadlock {
public static final Semaphore sem = new Semaphore(0);
public static final Semaphore sem2 = new Semaphore(0);
public static final Semaphore sem3 = new Semaphore(-2);
public static volatile boolean goOn = true;
public static volatile Exception thrown;
// Emulate EventQueue
static class FakeEventQueue {
static final Logger logger = Logger.getLogger("foo");
}
// Emulate AppContext
static class FakeAppContext {
final static AtomicInteger numAppContexts = new AtomicInteger(0);
static final class FakeAppContextLock {}
static final FakeAppContextLock lock = new FakeAppContextLock();
static volatile FakeAppContext appContext;
final FakeEventQueue queue;
FakeAppContext() {
appContext = this;
numAppContexts.incrementAndGet();
// release sem2 to let Thread t2 call Logger.getLogger().
sem2.release();
try {
// Wait until we JavaAWTAccess is called by LogManager.
// Thread 2 will call Logger.getLogger() which will
// trigger a call to JavaAWTAccess - which will release
// sem, thus ensuring that Thread #2 is where we want it.
sem.acquire();
System.out.println("Sem acquired: Thread #2 has called JavaAWTAccess");
} catch(InterruptedException x) {
Thread.interrupted();
}
queue = new FakeEventQueue();
}
static FakeAppContext getAppContext() {
synchronized (lock) {
if (numAppContexts.get() == 0) {
return new FakeAppContext();
}
return appContext;
}
}
static {
sun.misc.SharedSecrets.setJavaAWTAccess(new sun.misc.JavaAWTAccess() {
@Override
public Object getAppletContext() {
if (numAppContexts.get() == 0) return null;
// We are in JavaAWTAccess, we can release sem and let
// FakeAppContext constructor proceeed.
System.out.println("Releasing Sem");
sem.release();
return getAppContext();
}
});
}
}
// Test with or without a security manager
public static enum TestCase {
UNSECURE, SECURE;
public void run() throws Exception {
System.out.println("Running test case: " + name());
Configure.setUp(this);
test(this);
}
}
public static void test(TestCase test) throws Exception {
Thread t1 = new Thread() {
@Override
public void run() {
sem3.release();
System.out.println("FakeAppContext.getAppContext()");
FakeAppContext.getAppContext();
System.out.println("Done: FakeAppContext.getAppContext()");
}
};
t1.setDaemon(true);
t1.start();
Thread t2 = new Thread() {
public void run() {
sem3.release();
try {
// Wait until Thread1 is in FakeAppContext constructor
sem2.acquire();
System.out.println("Sem2 acquired: Thread #1 will be waiting to acquire Sem");
} catch (InterruptedException ie) {
Thread.interrupted();
}
System.out.println("Logger.getLogger(name).info(name)");
Logger.getLogger(test.name());//.info(name);
System.out.println("Done: Logger.getLogger(name).info(name)");
}
};
t2.setDaemon(true);
t2.start();
System.out.println("Should exit now...");
Thread detector = new DeadlockDetector();
detector.start();
// Wait for the 3 threads to start
sem3.acquire();
// Now wait for t1 & t2 to finish, or for a deadlock to be detected.
while (goOn && (t1.isAlive() || t2.isAlive())) {
if (t2.isAlive()) t2.join(1000);
if (test == TestCase.UNSECURE && System.getSecurityManager() == null) {
// if there's no security manager, AppContext.getAppContext() is
// not called - so Thread t2 will not end up calling
// sem.release(). In that case we must release the semaphore here
// so that t1 can proceed.
if (LogManager.getLogManager().getLogger(TestCase.UNSECURE.name()) != null) {
// means Thread t2 has created the logger
sem.release();
}
}
if (t1.isAlive()) t1.join(1000);
}
if (thrown != null) {
throw thrown;
}
}
// Thrown by the deadlock detector
static final class DeadlockException extends RuntimeException {
public DeadlockException(String message) {
super(message);
}
@Override
public void printStackTrace() {
}
}
public static void main(String[] args) throws Exception {
if (args.length == 0) {
args = new String[] { "SECURE" };
}
// If we don't initialize LogManager here, there will be
// a deadlock.
// See <https://bugs.openjdk.java.net/browse/JDK-8065709?focusedCommentId=13582038&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-13582038>
// for more details.
Logger.getLogger("main").info("starting...");
try {
TestCase.valueOf(args[0]).run();
System.out.println("Test "+args[0]+" Passed");
} catch(Throwable t) {
System.err.println("Test " + args[0] +" failed: " + t);
t.printStackTrace();
}
}
// Called by the deadlock detector when a deadlock is found.
static void fail(Exception x) {
x.printStackTrace();
if (thrown == null) {
thrown = x;
}
goOn = false;
}
// A thread that detect deadlocks.
final static class DeadlockDetector extends Thread {
public DeadlockDetector() {
this.setDaemon(true);
}
@Override
public void run() {
sem3.release();
Configure.doPrivileged(this::loop);
}
public void loop() {
while(goOn) {
try {
long[] ids = ManagementFactory.getThreadMXBean().findDeadlockedThreads();
ids = ids == null ? new long[0] : ids;
if (ids.length == 1) {
throw new RuntimeException("Found 1 deadlocked thread: "+ids[0]);
} else if (ids.length > 0) {
ThreadInfo[] infos = ManagementFactory.getThreadMXBean().getThreadInfo(ids, Integer.MAX_VALUE);
System.err.println("Found "+ids.length+" deadlocked threads: ");
for (ThreadInfo inf : infos) {
System.err.println(inf);
}
throw new DeadlockException("Found "+ids.length+" deadlocked threads");
}
Thread.sleep(100);
} catch(InterruptedException | RuntimeException x) {
fail(x);
}
}
}
}
// A helper class to configure the security manager for the test,
// and bypass it when needed.
static class Configure {
static Policy policy = null;
static final ThreadLocal<AtomicBoolean> allowAll = new ThreadLocal<AtomicBoolean>() {
@Override
protected AtomicBoolean initialValue() {
return new AtomicBoolean(false);
}
};
static void setUp(TestCase test) {
switch (test) {
case SECURE:
if (policy == null && System.getSecurityManager() != null) {
throw new IllegalStateException("SecurityManager already set");
} else if (policy == null) {
policy = new SimplePolicy(TestCase.SECURE, allowAll);
Policy.setPolicy(policy);
System.setSecurityManager(new SecurityManager());
}
if (System.getSecurityManager() == null) {
throw new IllegalStateException("No SecurityManager.");
}
if (policy == null) {
throw new IllegalStateException("policy not configured");
}
break;
case UNSECURE:
if (System.getSecurityManager() != null) {
throw new IllegalStateException("SecurityManager already set");
}
break;
default:
new InternalError("No such testcase: " + test);
}
}
static void doPrivileged(Runnable run) {
allowAll.get().set(true);
try {
run.run();
} finally {
allowAll.get().set(false);
}
}
}
// A Helper class to build a set of permissions.
final static class PermissionsBuilder {
final Permissions perms;
public PermissionsBuilder() {
this(new Permissions());
}
public PermissionsBuilder(Permissions perms) {
this.perms = perms;
}
public PermissionsBuilder add(Permission p) {
perms.add(p);
return this;
}
public PermissionsBuilder addAll(PermissionCollection col) {
if (col != null) {
for (Enumeration<Permission> e = col.elements(); e.hasMoreElements(); ) {
perms.add(e.nextElement());
}
}
return this;
}
public Permissions toPermissions() {
final PermissionsBuilder builder = new PermissionsBuilder();
builder.addAll(perms);
return builder.perms;
}
}
// Policy for the test...
public static class SimplePolicy extends Policy {
final Permissions permissions;
final Permissions allPermissions;
final ThreadLocal<AtomicBoolean> allowAll; // actually: this should be in a thread locale
public SimplePolicy(TestCase test, ThreadLocal<AtomicBoolean> allowAll) {
this.allowAll = allowAll;
// we don't actually need any permission to create our
// FileHandlers because we're passing invalid parameters
// which will make the creation fail...
permissions = new Permissions();
permissions.add(new RuntimePermission("accessClassInPackage.sun.misc"));
// these are used for configuring the test itself...
allPermissions = new Permissions();
allPermissions.add(new java.security.AllPermission());
}
@Override
public boolean implies(ProtectionDomain domain, Permission permission) {
if (allowAll.get().get()) return allPermissions.implies(permission);
return permissions.implies(permission);
}
@Override
public PermissionCollection getPermissions(CodeSource codesource) {
return new PermissionsBuilder().addAll(allowAll.get().get()
? allPermissions : permissions).toPermissions();
}
@Override
public PermissionCollection getPermissions(ProtectionDomain domain) {
return new PermissionsBuilder().addAll(allowAll.get().get()
? allPermissions : permissions).toPermissions();
}
}
}