<Swing Dev> [9] Review Request for 8130735: javax.swing.TimerQueue: timer fires late when another timer starts

[Alexander Zvegintsev]

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