On 4/11/2013 4:40 PM, Martin Buchholz wrote:
David and I might prefer a fix using AtomicInteger, but I don't think
there's anything incorrect with your fix - approved. Especially if you
have seen the flakiness has gone away. (I've never seen this test fail.)
+1
David
On Sun, Nov 3, 2013 at 8:14 PM, Tristan Yan <tristan....@oracle.com> wrote:
Thank you Martin
I updated the code as below
http://cr.openjdk.java.net/~ewang/tristan/JDK-8025198/webrev.02/
Thank you
On 11/04/2013 11:38 AM, Martin Buchholz wrote:
Tristan, I think your change it correct.
There are some stylistic improvements I would make:
- make lock final
- make lessThanCorePoolSize "blank final"; final boolean
lessThanCorePoolSize;
- add spaces after // and before {
On Sun, Nov 3, 2013 at 4:49 PM, Tristan Yan <tristan....@oracle.com>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.
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.[image: 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....@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?
