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https://issues.apache.org/jira/browse/CURATOR-79?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14092777#comment-14092777
]
ASF GitHub Bot commented on CURATOR-79:
---------------------------------------
Github user madrob commented on a diff in the pull request:
https://github.com/apache/curator/pull/35#discussion_r16053962
--- Diff:
curator-recipes/src/test/java/org/apache/curator/framework/recipes/locks/TestInterProcessMutex.java
---
@@ -107,4 +113,70 @@ public Void call() throws Exception
client.close();
}
}
+
+ /**
+ * See CURATOR-79. If the mutex is interrupted while attempting to
acquire a lock it is
+ * possible for the zNode to be created in ZooKeeper, but for Curator
to think that it
+ * hasn't been. This causes the next call to acquire() to fail because
the an orphaned
+ * zNode has been left behind from the previous call.
+ */
+ @Test
+ public void testInterruptedDuringAcquire() throws Exception
+ {
+ Timing timing = new Timing();
+ final CuratorFramework client =
CuratorFrameworkFactory.newClient(server.getConnectString(), new
RetryOneTime(1));
+ client.start();
+ final InterProcessMutex lock = new InterProcessMutex(client,
LOCK_PATH);
+
+ final AtomicBoolean interruptOnError = new AtomicBoolean(true);
+
+ ((CuratorFrameworkImpl)client).debugUnhandledErrorListener = new
UnhandledErrorListener()
+ {
+
+ @Override
+ public void unhandledError(String message, Throwable e)
+ {
+ if(interruptOnError.compareAndSet(true, false))
+ {
+ Thread.currentThread().interrupt();
+ }
+ }
+ };
+
+ //The lock path needs to exist for the deadlock to occur.
+ try {
+ client.create().creatingParentsIfNeeded().forPath(LOCK_PATH);
+ } catch(NodeExistsException e) {
+ }
+
+ try
+ {
+ //Interrupt the current thread. This will cause ensurePath()
to fail.
+ //We need to reinterrupt in the debugUnhandledErrorListener
above.
+ Thread.currentThread().interrupt();
+ lock.acquire();
+ Assert.fail();
+ }
+ catch(InterruptedException e)
+ {
+ //Expected lock to have failed.
+ Assert.assertTrue(!lock.isOwnedByCurrentThread());
--- End diff --
nit: assertFalse
> InterProcessMutex doesn't clean up after interrupt
> --------------------------------------------------
>
> Key: CURATOR-79
> URL: https://issues.apache.org/jira/browse/CURATOR-79
> Project: Apache Curator
> Issue Type: Bug
> Affects Versions: 2.0.0-incubating, 2.1.0-incubating, 2.2.0-incubating,
> 2.3.0
> Reporter: Orcun Simsek
> Assignee: Jordan Zimmerman
>
> InterProcessMutex can deadlock if a thread is interrupted during acquire().
> Specifically, CreateBuilderImpl.pathInForeground submits a create request to
> ZooKeeper, and an InterruptedException is thrown after the node is created in
> ZK but before ZK.create returns. ZK.create propagates a non-KeeperException,
> so Curator assumes the create has failed, but does not retry, and the node is
> now orphaned. At some point in the future, the node becomes the next in the
> acquisition sequence, but is not reclaimed as the ZK session has not expired.
> <stack trace attached in comments below>
> Curator should catch the InterruptedException and other non-KeeperExceptions,
> and delete the created node before propagating these exceptions.
> (as originally discussed on
> https://groups.google.com/forum/#!topic/curator-users/9ii5of8SbdQ)
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