Looks fine to me too. Thanks.
On 24.07.15 12:45, Alexander Scherbatiy wrote:
The fix looks good to me.
Thanks,
Alexandr.
On 7/23/2015 6:26 PM, Semyon Sadetsky wrote:
yes, the reporter wanted to make issue more frequent, but actually
skipping the stop() makes the real issue not reproducible at all.
The issue exists only for consequent start()/stop() calls and it's
very rare. Since it requires small timings there is a chance to catch
delay from the scheduler instead of the real problem.
As I mentioned in the initial message it is hard to write a stable
test scenario, so the bug is labeled noreg-hard.
--Semyon
On 7/23/2015 5:55 PM, Alexander Scherbatiy wrote:
The test from the bug report does not use timer.stop(). Is it
possible to write a test with timer.start()/stop() to reproduce the
original issue?
Thanks,
Alexandr.
On 7/22/2015 11:56 AM, Semyon Sadetsky wrote:
Yes, but then it will not very readable. I included you change with
some comments
http://cr.openjdk.java.net/~ssadetsky/8130735/webrev.03/.
--Semyon
On 7/22/2015 11:30 AM, Alexander Scherbatiy wrote:
On 7/22/2015 11:02 AM, Semyon Sadetsky wrote:
Alexander,
Thank you for the contribution. The final update:
http://cr.openjdk.java.net/~ssadetsky/8130735/webrev.02/
It looks like the runningTimer is never null so delayedTimer ==
runningTimer check always includes the delayedTimer to null check.
Thanks,
Alexandr.
--Semyon
On 7/21/2015 2:31 PM, Alexander Scherbatiy wrote:
On 7/21/2015 1:40 PM, Semyon Sadetsky wrote:
In the run() the delayed timer is obtained from timer, so it is
always the resulting delayed timer.
Just to use the delayed timer from the queue and not from the
timer?
TimerQueue.run(){
DelayedTimer delayedTimer = queue.take(); // note that this
delayed timer is not the same as timer.delayedTimer
delayedTimer.getTimer().lock();
if(delayedTimer.removed){
// skip it
}
// ...
delayedTimer.getTimer().unlock();
}
Thanks,
Alexandr.
How do you propose to detect that timer was renewed exactly
during the time interval between the timer is taken from the
queue and the lock is captured in the run() thread?
On 7/21/2015 12:53 PM, Alexander Scherbatiy wrote:
On 7/21/2015 11:36 AM, Semyon Sadetsky wrote:
Hi Alexander,
The remove() method set delayedTimer field to null, and it is
checked in run() to be not null. So it acts in the same way
as flag you've proposed.
The issue is about how to detect consequent remove() ans
add() in run(). If you use some flag in remove() then you
need to clear it in add()
I suppose that you are talking about some flags in Timer.
The proposed change suggests to add the flag to the
DelayedTimer. So after stopping a timer (timer.delayedTimer =
null) the delayedTimer taken from the queue contains
information that it has been removed.
Thanks,
Alexandr.
because after the add() the timer should run normally with
the new period. And you cannot clear such flag in the first
consequent run() after add() because you cannot determine the
moment the add() was called. So it is just the same problem.
--Semyon
On 7/21/2015 10:35 AM, Alexander Scherbatiy wrote:
What about to add removed flat to DelayedTimer? Something
like:
TimerQueue.removeTimer(Timer timer){
timer.lock();
// ...
timer.delayedTimer.removed = true;
queue.remove(timer.delayedTimer);
timer.delayedTimer = null;
timer.unlock();
}
TimerQueue.run(){
DelayedTimer delayedTimer = queue.take();
delayedTimer.getTimer().lock();
if(delayedTimer.removed){
// skip it
}
// ...
delayedTimer.getTimer().unlock();
}
Thanks,
Alexandr.
On 7/17/2015 12:28 AM, Sergey Bylokhov wrote:
Hi, Semyon.
I see that the chance to reproduce the problem is very very
small, because we should call addTimer, when we are at
lines 171/172. So the bug is about really small timings. So
the related question: Is it possible in the fixed version
to call addTimer when we remove DelayedTimer from the queue
via queue.take(), but before we assign its value to the
runningTimer?
On 14.07.15 12:51, Alexander Zvegintsev wrote:
still looks good to me.
Thanks,
Alexander.
On 07/14/2015 12:41 PM, Semyon Sadetsky wrote:
Hi Alexander,
I added the double check
:http://cr.openjdk.java.net/~ssadetsky/8130735/webrev.01/
--Semyon
On 7/13/2015 1:24 PM, Alexander Zvegintsev wrote:
Hello Semyon,
the fix looks good to me.
P.S. Just a side note, as I can see we could possibly
start two threads instead of one in startIfNeeded():
96 void startIfNeeded() {
97 if (! running) {
98 runningLock.lock();
99 try {
100 final ThreadGroup threadGroup =
AppContext.getAppContext().getThreadGroup();
101
AccessController.doPrivileged((PrivilegedAction<Object>)
() -> {
102 String name = "TimerQueue";
103 Thread timerThread = new
ManagedLocalsThread(threadGroup,
104 this, name);
!running check is missing after try. It is not the case
with current code base, but it may be changed in future.
Thanks,
Alexander.
On 07/09/2015 08:08 PM, Semyon Sadetsky wrote:
Hello,
Please review fix for JDK9:
bug: https://bugs.openjdk.java.net/browse/JDK-8130735
webrev:
http://cr.openjdk.java.net/~ssadetsky/8130735/webrev.00/
The root cause is the setting larger expiration time
for the timer which is already inserted into the delay
queue. So all timers behind the timer cannot be
executed earlier than its expiration time. This happens
very rare only for repeated timers and only if user
uses the Swing timer API inaccurately (call start()
without stop()).
The fix eliminates this possibility by introducing a
check if the timer was already restarted concurrently.
It is difficult to write test because I could not
reliably reproduce the issue for a reasonable time.
--Semyon
--
Best regards, Sergey.
--
Best regards, Sergey.
