RFR for JDK-8025198 Intermittent test failure: java/util/concurrent/ThreadPoolExecutor/ThrowingTasks.java
David Holmes
david.holmes at oracle.com
Mon Nov 4 01:09:08 UTC 2013
Hi Tristan,
On 4/11/2013 10:49 AM, Tristan Yan wrote:
> Thank you Martin
> I had code change. I took the similar way as you do here.
>
> Please review the code change for JDK-8025198.
> Description:
> Race condition exists in the test ThrowingTasks.java. We should sync
> CountDownLatch.countDown and CountDownLatch.getCount.
Locking access to a CountDownLatch just seems inherently wrong. I get
that it is the atomicity of the two calls that we want, but this still
seems unpleasant. I've looked at Martin's suggested fix and confess that
I am struggling to understand what exactly are we trying to achieve with
this synchronization ??
Thanks,
David
> http://cr.openjdk.java.net/~ewang/tristan/JDK-8025198/webrev.01/test/java/util/concurrent/ThreadPoolExecutor/ThrowingTasks.java.sdiff.html
>
>
> Thank you
> Tristan
>
>
> On 11/03/2013 12:46 PM, Martin Buchholz wrote:
>> I think the author of this test was sleep-deprived by baby Tristan
>> back in 2007.Inline image 1
>>
>> I tried and failed to find a single synchronizer that properly does
>> what we are trying to do with allStarted here. Too bad
>> CountDownLatch.countDown doesn't return the count. Best to introduce
>> another synchronizer. I propose this fix:
>>
>> diff --git
>> a/test/java/util/concurrent/ThreadPoolExecutor/ThrowingTasks.java
>> b/test/java/util/concurrent/ThreadPoolExecutor/ThrowingTasks.java
>> --- a/test/java/util/concurrent/ThreadPoolExecutor/ThrowingTasks.java
>> +++ b/test/java/util/concurrent/ThreadPoolExecutor/ThrowingTasks.java
>> @@ -136,6 +136,7 @@
>> }
>> static final CountDownLatch allStarted = new
>> CountDownLatch(flakes.size());
>> + static final AtomicInteger taskSerial = new AtomicInteger(0);
>> static final CountDownLatch allContinue = new CountDownLatch(1);
>> static class PermissiveSecurityManger extends SecurityManager {
>> @@ -164,7 +165,8 @@
>> }
>> @Override protected void beforeExecute(Thread t, Runnable r) {
>> allStarted.countDown();
>> - if (allStarted.getCount() < getCorePoolSize())
>> + // Get last core pool cohort to start in unison
>> + if (flakes.size() - taskSerial.incrementAndGet() < getCorePoolSize())
>> try { allContinue.await(); }
>> catch (InterruptedException x) { unexpected(x); }
>> beforeExecuteCount.getAndIncrement();
>>
>>
>>
>> On Fri, Nov 1, 2013 at 6:48 PM, Tristan Yan <tristan.yan at oracle.com
>> <mailto:tristan.yan at oracle.com>> wrote:
>>
>> This only happened when I tried a 1000 times loop run, see the
>> jstack out put below:
>> Also by using jmap/jhat, below values help me find the reason
>> flakes.size() = 25
>> allStarted.state = 1
>> beforeExecuteCount.count = 1
>>
>> Full thread dump Java HotSpot(TM) 64-Bit Server VM (25.0-b56 mixed
>> mode):
>>
>> "Attach Listener" #32 daemon prio=9 os_prio=31
>> tid=0x00007faf1d808000 nid=0x390b waiting on condition
>> [0x0000000000000000]
>> java.lang.Thread.State: RUNNABLE
>>
>> "Thread-22" #31 prio=5 os_prio=31 tid=0x00007faf1d07b000
>> nid=0x5d0b waiting on condition [0x000000019b530000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-21" #30 prio=5 os_prio=31 tid=0x00007faf1d80c800
>> nid=0x5507 waiting on condition [0x000000019ae1b000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-20" #29 prio=5 os_prio=31 tid=0x00007faf1c10b000
>> nid=0x6307 waiting on condition [0x000000019b227000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-18" #27 prio=5 os_prio=31 tid=0x00007faf1c10a000
>> nid=0x6107 waiting on condition [0x000000019b42d000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-14" #23 prio=5 os_prio=31 tid=0x00007faf1d80c000
>> nid=0x500b waiting on condition [0x000000019ad18000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-13" #22 prio=5 os_prio=31 tid=0x00007faf1c108800
>> nid=0x5f03 waiting on condition [0x000000019b32a000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-12" #21 prio=5 os_prio=31 tid=0x00007faf1d80b000
>> nid=0x540b waiting on condition [0x000000019ab12000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-10" #19 prio=5 os_prio=31 tid=0x00007faf1d80a800
>> nid=0x5107 waiting on condition [0x000000019af1e000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-6" #14 prio=5 os_prio=31 tid=0x00007faf1d809800 nid=0x5807
>> waiting on condition [0x000000019ac15000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Thread-8" #16 prio=5 os_prio=31 tid=0x00007faf1d809000 nid=0x5b03
>> waiting on condition [0x000000019b124000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e9610> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at
>> ThrowingTasks$CheckingExecutor.beforeExecute(ThrowingTasks.java:168)
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1139)
>>
>> at
>>
>> java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
>>
>> at java.lang.Thread.run(Thread.java:744)
>>
>> "Service Thread" #8 daemon prio=9 os_prio=31
>> tid=0x00007faf1c837000 nid=0x4b03 runnable [0x0000000000000000]
>> java.lang.Thread.State: RUNNABLE
>>
>> "C1 CompilerThread2" #7 daemon prio=9 os_prio=31
>> tid=0x00007faf1c816000 nid=0x4903 waiting on condition
>> [0x0000000000000000]
>> java.lang.Thread.State: RUNNABLE
>>
>> "C2 CompilerThread1" #6 daemon prio=9 os_prio=31
>> tid=0x00007faf1c809800 nid=0x4703 waiting on condition
>> [0x0000000000000000]
>> java.lang.Thread.State: RUNNABLE
>>
>> "C2 CompilerThread0" #5 daemon prio=9 os_prio=31
>> tid=0x00007faf1c818000 nid=0x4503 waiting on condition
>> [0x0000000000000000]
>> java.lang.Thread.State: RUNNABLE
>>
>> "Signal Dispatcher" #4 daemon prio=9 os_prio=31
>> tid=0x00007faf1c078800 nid=0x4303 runnable [0x0000000000000000]
>> java.lang.Thread.State: RUNNABLE
>>
>> "Finalizer" #3 daemon prio=8 os_prio=31 tid=0x00007faf1c811000
>> nid=0x2d03 in Object.wait() [0x00000001999be000]
>> java.lang.Thread.State: WAITING (on object monitor)
>> at java.lang.Object.wait(Native Method)
>> - waiting on <0x0000000168286218> (a
>> java.lang.ref.ReferenceQueue$Lock)
>> at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:142)
>> - locked <0x0000000168286218> (a
>> java.lang.ref.ReferenceQueue$Lock)
>> at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:158)
>> at
>> java.lang.ref.Finalizer$FinalizerThread.run(Finalizer.java:189)
>>
>> "Reference Handler" #2 daemon prio=10 os_prio=31
>> tid=0x00007faf1c810800 nid=0x2b03 in Object.wait()
>> [0x00000001998bb000]
>> java.lang.Thread.State: WAITING (on object monitor)
>> at java.lang.Object.wait(Native Method)
>> - waiting on <0x0000000168285c88> (a
>> java.lang.ref.Reference$Lock)
>> at java.lang.Object.wait(Object.java:502)
>> at
>> java.lang.ref.Reference$ReferenceHandler.run(Reference.java:157)
>> - locked <0x0000000168285c88> (a java.lang.ref.Reference$Lock)
>>
>> "main" #1 prio=5 os_prio=31 tid=0x00007faf1c800000 nid=0x1b03
>> waiting on condition [0x000000010386e000]
>> java.lang.Thread.State: WAITING (parking)
>> at sun.misc.Unsafe.park(Native Method)
>> - parking to wait for <0x00000001683e95e0> (a
>> java.util.concurrent.CountDownLatch$Sync)
>> at
>> java.util.concurrent.locks.LockSupport.park(LockSupport.java:175)
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:836)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.doAcquireSharedInterruptibly(AbstractQueuedSynchronizer.java:997)
>>
>> at
>>
>> java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireSharedInterruptibly(AbstractQueuedSynchronizer.java:1304)
>>
>> at
>> java.util.concurrent.CountDownLatch.await(CountDownLatch.java:231)
>> at ThrowingTasks.realMain(ThrowingTasks.java:207)
>> at ThrowingTasks.main(ThrowingTasks.java:267)
>>
>> "VM Thread" os_prio=31 tid=0x00007faf1c066000 nid=0x2903 runnable
>>
>> "GC task thread#0 (ParallelGC)" os_prio=31 tid=0x00007faf1c80d000
>> nid=0x2103 runnable
>>
>> "GC task thread#1 (ParallelGC)" os_prio=31 tid=0x00007faf1c012000
>> nid=0x2303 runnable
>>
>> "GC task thread#2 (ParallelGC)" os_prio=31 tid=0x00007faf1c80e000
>> nid=0x2503 runnable
>>
>> "GC task thread#3 (ParallelGC)" os_prio=31 tid=0x00007faf1c013000
>> nid=0x2703 runnable
>>
>> "VM Periodic Task Thread" os_prio=31 tid=0x00007faf1c06c800
>> nid=0x4d03 waiting on condition
>>
>> JNI global references: 7
>>
>>
>> On 02/11/2013 04:01, Martin Buchholz wrote:
>>>
>>>
>>> Including a jstack output extract might be useful for diagnosis.
>>>
>>> I have never seen this test fail. Is there a hint that might
>>> allow me to reproduce it?
>>
>>
>
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