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8240340: java/lang/management/ThreadMXBean/Locks.java is buggy
Reviewed-by: dholmes, sspitsyn
  • Loading branch information
Alex Menkov committed Mar 11, 2020
1 parent db69852 commit 5531199db4fe4a33de0eb1f739ed685d0dad4a76
Showing with 80 additions and 89 deletions.
  1. +69 −59 test/jdk/java/lang/management/ThreadMXBean/Locks.java
  2. +11 −30 test/lib/jdk/test/lib/LockFreeLogger.java
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2003, 2016, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2003, 2020, 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
@@ -89,25 +89,22 @@ private static void printStackTrace(Thread thread) {

private static void assertThreadState(Thread t, Thread.State expectedState) {
long tid = t.getId();
if (expectedState == Thread.State.BLOCKED
&& TM.getThreadInfo(tid).getThreadState() != Thread.State.BLOCKED) {
int retryCount = 0;
printStackTrace(t);
while (TM.getThreadInfo(tid).getThreadState() != Thread.State.BLOCKED) {
if (retryCount++ > 500) {
printStackTrace(t);
throw new RuntimeException("Thread " + t.getName() + " is at "
+ TM.getThreadInfo(tid).getThreadState() + " state but is expected to "
+ "be in Thread.State = " + expectedState);
}
goSleep(100);
Thread.State actualState = TM.getThreadInfo(tid).getThreadState();
if (!actualState.equals(expectedState)) {
if (expectedState.equals(Thread.State.BLOCKED)) {
int retryCount = 0;
printStackTrace(t);
do {
goSleep(100);
actualState = TM.getThreadInfo(tid).getThreadState();
} while (!actualState.equals(expectedState) && retryCount++ <= 500);
}
if (!actualState.equals(expectedState)) {
printStackTrace(t);
throw new RuntimeException("Thread " + t.getName() + " is at "
+ actualState + " state but is expected to "
+ "be in Thread.State = " + expectedState);
}
}
if (!TM.getThreadInfo(tid).getThreadState().equals(expectedState)) {
printStackTrace(t);
throw new RuntimeException("Thread " + t.getName() + " is at "
+ TM.getThreadInfo(tid).getThreadState() + " state but is expected to "
+ "be in Thread.State = " + expectedState);
}
}

@@ -164,6 +161,7 @@ static class LockAThread extends Thread {
public LockAThread(Phaser p) {
super("LockAThread");
this.p = p;
setDaemon(true);
}
@Override
public void run() {
@@ -187,6 +185,7 @@ static class LockBThread extends Thread {
public LockBThread(Phaser p) {
super("LockBThread");
this.p = p;
setDaemon(true);
}
@Override
public void run() {
@@ -237,42 +236,40 @@ static class WaitingThread extends Thread {
public WaitingThread(Phaser p) {
super("WaitingThread");
this.p = p;
setDaemon(true);
}

@Override
public void run() {
synchronized(OBJC) {
log("WaitingThread about to wait on OBJC");
try {
try {
synchronized (OBJC) {
log("WaitingThread about to wait on OBJC");
// Signal checker thread, about to wait on OBJC.
waiting = false;
p.arriveAndAwaitAdvance(); // Phase 1 (waiting)
waiting = true;
OBJC.doWait();
} catch (InterruptedException e) {
throw new RuntimeException(e); // Do not continue test
}

// block until CheckerThread finishes checking
log("WaitingThread about to block on ready");
// signal checker thread that it is about acquire
// object ready.
p.arriveAndAwaitAdvance(); // Phase 2 (waiting)
synchronized(ready) {
dummyCounter++;
// block until CheckerThread finishes checking
log("WaitingThread about to block on ready");
// signal checker thread that it is about acquire
// object ready.
p.arriveAndAwaitAdvance(); // Phase 2 (waiting)
synchronized (ready) {
dummyCounter++;
}
}
}
synchronized(OBJC) {
try {
synchronized (OBJC) {
// signal checker thread, about to wait on OBJC
waiting = false;
p.arriveAndAwaitAdvance(); // Phase 3 (waiting)
waiting = true;
OBJC.doWait();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
log("WaitingThread about to exit waiting on OBJC 2");
} catch (InterruptedException e) {
// test failed and this thread was interrupted
}
log("WaitingThread about to exit waiting on OBJC 2");
}

public void waitForWaiting() {
@@ -294,37 +291,49 @@ private void waitForState(Thread.State state) {
}
}
}

static class CheckerThread extends Thread {
private Exception result = null;

public CheckerThread() {
super("CheckerThread");
setDaemon(true);
}

@Override
public void run() {
synchronized(ready) {
// wait until WaitingThread about to wait for OBJC
waiter.waitForWaiting(); // Phase 1 (waiting)
assertThreadState(waiter, Thread.State.WAITING);
checkBlockedObject(waiter, OBJC, null);
try {
synchronized (ready) {
// wait until WaitingThread about to wait for OBJC
waiter.waitForWaiting(); // Phase 1 (waiting)
assertThreadState(waiter, Thread.State.WAITING);
checkBlockedObject(waiter, OBJC, null);
synchronized (OBJC) {
OBJC.doNotify();
}
// wait for waiter thread to about to enter
// synchronized object ready.
waiter.waitForBlocked(); // Phase 2 (waiting)
assertThreadState(waiter, Thread.State.BLOCKED);
checkBlockedObject(waiter, ready, this);
}

synchronized(OBJC) {
// wait for signal from waiting thread that it is about
// wait for OBJC.
waiter.waitForWaiting(); // Phase 3 (waiting)
synchronized (OBJC) {
assertThreadState(waiter, Thread.State.WAITING);
checkBlockedObject(waiter, OBJC, Thread.currentThread());
OBJC.doNotify();
}
// wait for waiter thread to about to enter
// synchronized object ready.
waiter.waitForBlocked(); // Phase 2 (waiting)
assertThreadState(waiter, Thread.State.BLOCKED);
checkBlockedObject(waiter, ready, this);
} catch (Exception e) {
waiter.interrupt();
result = e;
}
}

// wait for signal from waiting thread that it is about
// wait for OBJC.
waiter.waitForWaiting(); // Phase 3 (waiting)
synchronized(OBJC) {
assertThreadState(waiter, Thread.State.WAITING);
checkBlockedObject(waiter, OBJC, Thread.currentThread());
OBJC.doNotify();
}
Exception result() {
return result;
}
}

@@ -368,16 +377,17 @@ public static void main(String args[]) throws Exception {
// Test Object.wait() case
waiter = new WaitingThread(p);
waiter.start();

checker = new CheckerThread();
checker.start();

try {
waiter.join();
checker.join();
} catch (InterruptedException e) {
throw new RuntimeException(e);
}
if (checker.result() != null) {
throw checker.result();
}
} finally { // log all the messages to STDOUT
System.out.println(LOGGER.toString());
}
@@ -1,5 +1,5 @@
/*
* Copyright (c) 2014, 2017, Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 2014, 2020, 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
@@ -23,12 +23,8 @@

package jdk.test.lib;

import java.util.Collection;
import java.util.Comparator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;

/**
@@ -38,47 +34,32 @@
* It is particularly useful in situations when one needs to assert various
* details about the tested thread state or the locks it hold while also wanting
* to produce diagnostic log messages.
* <p>
* The logger does not provide any guarantees about the completness of the
* logs written from different threads - it is up to the caller to make sure
* {@code toString()} method is called only when all the activity has ceased
* and the per-thread logs contain all the necessary data.
*
* @author Jaroslav Bachorik
**/
*/
public class LockFreeLogger {
private final AtomicInteger logCntr = new AtomicInteger(0);
private final Collection<Map<Integer, String>> allRecords = new ConcurrentLinkedQueue<>();
private final ThreadLocal<Map<Integer, String>> records = ThreadLocal.withInitial(ConcurrentHashMap::new);
/**
* ConcurrentLinkedQueue implements non-blocking algorithm.
*/
private final Queue<String> records = new ConcurrentLinkedQueue<>();

public LockFreeLogger() {
allRecords.add(records.get());
}

/**
* Log a message
* Logs a message.
* @param format Message format
* @param params Message parameters
*/
public void log(String format, Object ... params) {
int id = logCntr.getAndIncrement();
records.get().put(id, String.format(format, params));
records.add(String.format(format, params));
}

/**
* Will generate an aggregated log of chronologically ordered messages.
* <p>
* Make sure that you call this method only when all the related threads
* have finished; otherwise you might get incomplete data.
* Generates an aggregated log of chronologically ordered messages.
*
* @return An aggregated log of chronologically ordered messages
*/
@Override
public String toString() {
return allRecords.stream()
.flatMap(m -> m.entrySet().stream())
.sorted(Comparator.comparing(Map.Entry::getKey))
.map(Map.Entry::getValue)
.collect(Collectors.joining());
return records.stream().collect(Collectors.joining());
}
}

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