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https://issues.apache.org/jira/browse/CURATOR-89?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13907545#comment-13907545
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David Kesler commented on CURATOR-89:
-------------------------------------
Just verified that the CloseableScheduledExecutorService seems to be causing
the problem. I did an experiment with a forked ChildReaper that just used a
vanilla ScheduledExecutorService and doWork gets called repeatedly as expected.
> ChildReaper only checks for children once
> -----------------------------------------
>
> Key: CURATOR-89
> URL: https://issues.apache.org/jira/browse/CURATOR-89
> Project: Apache Curator
> Issue Type: Bug
> Reporter: David Kesler
> Assignee: Jordan Zimmerman
>
> I've created a child reaper for a particular path underneath which have a
> bunch of lock paths that I want cleaned up periodically. The problem is that
> I'm seeing ChildReaper.doWork only get called once. Thus newly added
> children nodes never get picked up by the child reaper and passed to the
> actual reaper.
> The problem appears to be the fact that an InternalFutureTask is being
> submitted to the ScheduledExecutorService through the
> ClosableScheduledExecutorService that ChildReaper uses. Putting a breakpoint
> on java's FutureTask.run and FutureTask.runAndReset, it looks like what
> happens is that when the InternalFutureTask gets submitted to the
> ScheduledExecutorService, another task gets created. THAT task wraps the
> InternalFutureTask that the ClosableScheduledExecutorService submitted to the
> real executor and correctly gets executed repeatedly via its runAndReset
> method. However when the outermost task executes it calls .run on the
> wrapped InternalFutureTask. The first time the InternalFutureTask itself is
> executed, the state of it's Sync field gets set to RAN (2). Then every
> future invocation of run on the InternaFutureTask is ignored because the task
> has already run.
> The Reaper itself doesn't seem to have a problem because it's manually
> rescheduling the task after every invocation rather than using
> scheduleWithFixedInterval.
> I don't know if it makes a difference, but I'm using the default scheduled
> executor for ChildReaper. I'm using java 6 and tried both curator 2.1.0 and
> 2.4.0
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