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[GR-44559] Finish ThreadMXBean implementation for Native Image. #8430

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Original file line number Diff line number Diff line change
@@ -0,0 +1,43 @@
/*
* Copyright (c) 2023, 2024, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.oracle.svm.core.jdk;

import com.oracle.svm.core.annotate.Alias;
import com.oracle.svm.core.annotate.TargetClass;

@SuppressWarnings({"unused"})
@TargetClass(java.lang.management.ThreadInfo.class)
final class Target_java_lang_management_ThreadInfo {

@Alias
Target_java_lang_management_ThreadInfo(Thread t, int state, Object lockObj, Thread lockOwner,
long blockedCount, long blockedTime,
long waitedCount, long waitedTime,
StackTraceElement[] stackTrace,
Object[] monitors,
int[] stackDepths,
Object[] synchronizers) {
}
}
Original file line number Diff line number Diff line change
@@ -0,0 +1,158 @@
/*
* Copyright (c) 2023, 2024, 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. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package com.oracle.svm.core.jdk;

import com.oracle.svm.core.SubstrateUtil;
import com.oracle.svm.core.jdk.management.SubstrateThreadMXBean;
import com.oracle.svm.core.locks.Target_java_util_concurrent_locks_AbstractOwnableSynchronizer;
import com.oracle.svm.core.monitor.JavaMonitor;
import com.oracle.svm.core.thread.JavaThreads.JMXMonitoring;
import com.oracle.svm.core.thread.PlatformThreads;

import java.lang.management.ThreadInfo;
import java.util.Arrays;
import java.util.HashSet;
import java.util.List;
import java.util.concurrent.locks.AbstractOwnableSynchronizer;
import java.util.concurrent.locks.LockSupport;

/**
* Utils to support {@link SubstrateThreadMXBean} for providing threading information for JMX
* support. Include the {@link ThreadInfo} constructing utils, and deadlock detection utils.
*/
public class ThreadMXUtils {

public static class ThreadInfoConstructionUtils {

private static StackTraceElement[] getStackTrace(Thread thread, int maxDepth) {
StackTraceElement[] stackTrace = thread.getStackTrace();
return maxDepth == -1 || maxDepth >= stackTrace.length ? stackTrace : Arrays.copyOfRange(stackTrace, 0, maxDepth);
}

private record Blocker(Object blockObject, Thread ownerThread) {
}

private static Blocker getBlockerInfo(Thread thread) {
Object blocker = LockSupport.getBlocker(thread);

if (blocker instanceof JavaMonitor javaMonitor) {
return new Blocker(
javaMonitor.getBlockedObject(),
SubstrateThreadMXBean.getThreadById(javaMonitor.getOwnerThreadId()));
} else if (blocker instanceof AbstractOwnableSynchronizer synchronizer) {
return new Blocker(synchronizer,
SubstrateUtil.cast(synchronizer, Target_java_util_concurrent_locks_AbstractOwnableSynchronizer.class)
.getExclusiveOwnerThread());
}
return new Blocker(blocker, null);
}

private static Object[] getLockedSynchronizers(Thread thread) {
return JMXMonitoring.getThreadLocks(thread);
}

private record LockedMonitors(Object[] monitorObjects, int[] monitorDepths) {
}

private static LockedMonitors getLockedMonitors(Thread thread, int stacktraceLength) {
List<JMXMonitoring.MonitorInfo> monitors = JMXMonitoring.getThreadMonitors(thread);
Object[] monitorObjects = monitors.stream().map(JMXMonitoring.MonitorInfo::originalObject).toArray();
int[] monitorDepths = monitors.stream().mapToInt(monitorInfo -> stacktraceLength < 0 ? -1 : stacktraceLength - monitorInfo.stacksize()).toArray();
return new LockedMonitors(monitorObjects, monitorDepths);
}

private static int getThreadState(Thread thread, boolean inNative) {
int state = PlatformThreads.getThreadStatus(thread);
if (inNative) {
// set the JMM thread state native flag to true:
state |= 0x00400000;
}
return state;
}

public static ThreadInfo getThreadInfo(Thread thread, int maxDepth,
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What should this method return if the thread is no longer
a. alive
b. blocked

I think a lot of corner cases are missing here.

boolean withLockedMonitors, boolean withLockedSynchronizers) {
Blocker blocker = getBlockerInfo(thread);
StackTraceElement[] stackTrace = getStackTrace(thread, maxDepth);
LockedMonitors lockedMonitors = getLockedMonitors(thread, stackTrace.length);
boolean inNative = stackTrace.length > 0 && stackTrace[0].isNativeMethod();
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This is not correct - you would need to access the VM-internal thread state of the isolate thread but this isn't accessible easily for threads other than the current thread.

Target_java_lang_management_ThreadInfo targetThreadInfo = new Target_java_lang_management_ThreadInfo(
thread,
getThreadState(thread, inNative),
blocker.blockObject,
blocker.ownerThread,
JMXMonitoring.getThreadTotalBlockedCount(thread),
JMXMonitoring.getThreadTotalBlockedTime(thread),
JMXMonitoring.getThreadTotalWaitedCount(thread),
JMXMonitoring.getThreadTotalWaitedTime(thread),
stackTrace,
withLockedMonitors ? lockedMonitors.monitorObjects : new Object[0],
withLockedMonitors ? lockedMonitors.monitorDepths : new int[0],
withLockedSynchronizers ? getLockedSynchronizers(thread) : new Object[0]);
return SubstrateUtil.cast(targetThreadInfo, ThreadInfo.class);
}
}

public static class DeadlockDetectionUtils {
/**
* Returns an array of thread ids of blocked threads within some given array of ThreadInfo.
*
* @param threadInfos array of ThreadInfo for the threads among which the deadlocks should
* be detected
* @param byMonitorOnly true if we are interested only in the deadlocks blocked exclusively
* on monitors
* @return array containing thread ids of deadlocked threads
*/
public static long[] findDeadlockedThreads(ThreadInfo[] threadInfos, boolean byMonitorOnly) {
HashSet<Long> deadlocked = new HashSet<>();
for (ThreadInfo threadInfo : threadInfos) {
HashSet<Long> chain = new HashSet<>();
ThreadInfo current = threadInfo;
while (current != null && current.getLockInfo() != null && !deadlocked.contains(current.getThreadId())) {
if (!chain.add(current.getThreadId())) {
if (!byMonitorOnly || chain.stream().allMatch(DeadlockDetectionUtils::isBlockedByMonitor)) {
deadlocked.addAll(chain);
}
chain.clear();
break;
}
long currentLockOwnerId = current.getLockOwnerId();
current = Arrays.stream(threadInfos).filter(ti -> ti.getThreadId() == currentLockOwnerId).findAny().orElse(null);
}
}
return deadlocked.stream().mapToLong(threadId -> threadId).toArray();
}

/**
* Anything that is deadlocked can be blocked either by monitor (the object related to
* JavaMonitor), or a lock (anything under AbstractOwnableSynchronizer).
*
* @return true if provided thread is blocked by a monitor
*/
private static boolean isBlockedByMonitor(long threadId) {
return LockSupport.getBlocker(SubstrateThreadMXBean.getThreadById(threadId)) instanceof JavaMonitor;
}
}
}
Original file line number Diff line number Diff line change
Expand Up @@ -24,6 +24,8 @@
*/
package com.oracle.svm.core.jdk.management;

import static com.oracle.svm.core.Uninterruptible.CALLED_FROM_UNINTERRUPTIBLE_CODE;

import java.lang.management.ManagementFactory;
import java.lang.management.ThreadInfo;
import java.util.Arrays;
Expand All @@ -36,6 +38,8 @@
import org.graalvm.nativeimage.Platforms;

import com.oracle.svm.core.Uninterruptible;
import com.oracle.svm.core.jdk.ThreadMXUtils;
import com.oracle.svm.core.jdk.ThreadMXUtils.ThreadInfoConstructionUtils;
import com.oracle.svm.core.jdk.UninterruptibleUtils.AtomicInteger;
import com.oracle.svm.core.jdk.UninterruptibleUtils.AtomicLong;
import com.oracle.svm.core.thread.PlatformThreads;
Expand All @@ -55,9 +59,9 @@ public final class SubstrateThreadMXBean implements com.sun.management.ThreadMXB
private final AtomicInteger peakThreadCount = new AtomicInteger(0);
private final AtomicInteger threadCount = new AtomicInteger(0);
private final AtomicInteger daemonThreadCount = new AtomicInteger(0);

private boolean allocatedMemoryEnabled;
private boolean cpuTimeEnabled;
private boolean contentionMonitoringEnabled;

@Platforms(Platform.HOSTED_ONLY.class)
SubstrateThreadMXBean() {
Expand Down Expand Up @@ -150,45 +154,62 @@ public int getDaemonThreadCount() {
return daemonThreadCount.get();
}

/* All remaining methods are unsupported on Substrate VM. */

@Override
public long[] getAllThreadIds() {
return new long[0];
return Arrays.stream(PlatformThreads.getAllThreads())
.mapToLong(Thread::threadId)
.toArray();
}

public static Thread getThreadById(long id) {
return Arrays.stream(PlatformThreads.getAllThreads())
.filter(thread -> thread.threadId() == id)
.findAny().orElse(null);
}

@Override
public ThreadInfo getThreadInfo(long id) {
return null;
return getThreadInfo(id, -1);
}

@Override
public ThreadInfo[] getThreadInfo(long[] ids) {
return new ThreadInfo[0];
return getThreadInfo(ids, -1);
}

@Override
public ThreadInfo getThreadInfo(long id, int maxDepth) {
return null;
return getThreadInfo(id, maxDepth, false, false);
}

private static ThreadInfo getThreadInfo(long id, int maxDepth, boolean lockedMonitors, boolean lockedSynchronizers) {
Thread thread = getThreadById(id);
return getThreadInfo(thread, maxDepth, lockedMonitors, lockedSynchronizers);
}

private static ThreadInfo getThreadInfo(Thread thread, int maxDepth, boolean lockedMonitors, boolean lockedSynchronizers) {
return thread == null ? null : ThreadInfoConstructionUtils.getThreadInfo(thread, maxDepth, lockedMonitors, lockedSynchronizers);
}

@Override
public ThreadInfo[] getThreadInfo(long[] ids, int maxDepth) {
return new ThreadInfo[0];
return (ThreadInfo[]) Arrays.stream(ids).mapToObj(id -> getThreadInfo(id, maxDepth)).toArray();
}

@Override
public boolean isThreadContentionMonitoringSupported() {
return false;
return true;
}

@Override
@Uninterruptible(reason = CALLED_FROM_UNINTERRUPTIBLE_CODE, mayBeInlined = true)
public boolean isThreadContentionMonitoringEnabled() {
return false;
return contentionMonitoringEnabled;
}

@Override
public void setThreadContentionMonitoringEnabled(boolean enable) {
public void setThreadContentionMonitoringEnabled(boolean value) {
contentionMonitoringEnabled = value;
}

@Override
Expand Down Expand Up @@ -256,32 +277,36 @@ public void setThreadCpuTimeEnabled(boolean enable) {

@Override
public long[] findMonitorDeadlockedThreads() {
return new long[0];
ThreadInfo[] threadInfos = dumpAllThreads(true, false);
return ThreadMXUtils.DeadlockDetectionUtils.findDeadlockedThreads(threadInfos, true);
}

@Override
public long[] findDeadlockedThreads() {
return new long[0];
ThreadInfo[] threadInfos = dumpAllThreads(true, true);
return ThreadMXUtils.DeadlockDetectionUtils.findDeadlockedThreads(threadInfos, false);
}

@Override
public boolean isObjectMonitorUsageSupported() {
return false;
return true;
}

@Override
public boolean isSynchronizerUsageSupported() {
return false;
return true;
}

@Override
public ThreadInfo[] getThreadInfo(long[] ids, boolean lockedMonitors, boolean lockedSynchronizers) {
return new ThreadInfo[0];
return Arrays.stream(ids).mapToObj(id -> getThreadInfo(id, -1, lockedMonitors, lockedSynchronizers))
.toArray(ThreadInfo[]::new);
}

@Override
public ThreadInfo[] dumpAllThreads(boolean lockedMonitors, boolean lockedSynchronizers) {
return new ThreadInfo[0];
return Arrays.stream(PlatformThreads.getAllThreads()).map(thread -> getThreadInfo(thread, -1, lockedMonitors, lockedSynchronizers))
.toArray(ThreadInfo[]::new);
}

@Override
Expand All @@ -290,7 +315,6 @@ public long getThreadAllocatedBytes(long id) {
if (!valid) {
return -1;
}

return PlatformThreads.getThreadAllocatedBytes(id);
}

Expand Down Expand Up @@ -324,8 +348,8 @@ private static void verifyThreadId(long id) {
}

private static void verifyThreadIds(long[] ids) {
for (int i = 0; i < ids.length; i++) {
verifyThreadId(ids[i]);
for (long id : ids) {
verifyThreadId(id);
}
}

Expand Down
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