Hmm, sorry but did you provide a sample? I dont see it (maybe gmail issue).
yes org.apache.openejb.util.classloader.URLClassLoaderFirst#LOCK seems wrong, we should stick to synchronized here and maybe even activate java 7 parallel classloading when available Romain Manni-Bucau @rmannibucau <https://twitter.com/rmannibucau> | Blog <http://rmannibucau.wordpress.com> | Github <https://github.com/rmannibucau> | LinkedIn <https://www.linkedin.com/in/rmannibucau> | Tomitriber <http://www.tomitribe.com> 2015-04-02 15:55 GMT+02:00 tschuler <[email protected]>: > Hi Romain! > > I looked into oracle java and TomEE source files but cannot figure out the > root cause for the deadlock so far. > I added an example of two threads in deadlock situation. It is based on > JDK 8 & TomEE 1.7.1 (but I saw a similar thread deadlock with JDK 7 too). > > In URLClassLoaderFirst a ReentrantLock was introduced for TomEE 1.7.X that > seems to be part of the problem, because we never observed a thread > deadlock with TomEE 1.6.X & JDK 7. > Second thread “BpmClusteredScheduler_Worker-2” is waiting for it. > > The first thread (“org.junitee.runner.TestRunner”) is waiting at the > synchronized(this) block in java.util.ClassLoader (method checkCerts). > > Maybe the example could help to find the cause for the thread deadlock. > If more examples are needed: I have a few more. > > Best regards, > Thomas > > > From: Romain Manni-Bucau [via TomEE & OpenEJB] [mailto: > [email protected]] > Sent: Montag, 30. März 2015 11:09 > To: Thomas Schuler > Subject: Re: thread deadlock at URLClassLoaderFirst > > > https://repository.apache.org/content/groups/snapshots/org/apache/openejb/apache-tomee/1.7.2-SNAPSHOT/ > > > Romain Manni-Bucau > @rmannibucau <https://twitter.com/rmannibucau> | Blog > <http://rmannibucau.wordpress.com> | Github < > https://github.com/rmannibucau> | > LinkedIn <https://www.linkedin.com/in/rmannibucau> | Tomitriber > <http://www.tomitribe.com> > > 2015-03-30 11:03 GMT+02:00 tschuler <[hidden > email]</user/SendEmail.jtp?type=node&node=4674223&i=0>>: > > > Hi Romain! > > > > Can you please provide 1.7.2 snapshot url for download? > > I'll give it a try. > > > > Best regards, > > Thomas > > > > From: Romain Manni-Bucau [via TomEE & OpenEJB] [mailto: > > [hidden email]</user/SendEmail.jtp?type=node&node=4674223&i=1>] > > Sent: Freitag, 27. März 2015 16:07 > > To: Thomas Schuler > > Subject: Re: thread deadlock at URLClassLoaderFirst > > > > Hi > > > > wonder if it is not fixed on snapshots (if you can try it would be > welcomed > > since we'll release 1.7.2 soon) > > > > as a workaround you can prevload the locking classes in a > > ServletContextListener. Should not be the sexiest but the easiest to > setup. > > > > > > Romain Manni-Bucau > > @rmannibucau <https://twitter.com/rmannibucau> | Blog > > <http://rmannibucau.wordpress.com> | Github < > > https://github.com/rmannibucau> | > > LinkedIn <https://www.linkedin.com/in/rmannibucau> | Tomitriber > > <http://www.tomitribe.com> > > > > 2015-03-27 15:59 GMT+01:00 tschuler <[hidden > > email]</user/SendEmail.jtp?type=node&node=4674198&i=0>>: > > > > > Hi! > > > > > > We use TomEE 1.7.1 and get in troubles from time to time because of a > > > thread > > > dead lock resulting in an idle TomEE. It is always the same pattern as > > > shown > > > below - deadlock at > > > org.apache.openejb.util.classloader.URLClassLoaderFirst. > > > > > > Extract from JVisualVM thread dump: > > > > > > Found one Java-level deadlock > > > ============================= > > > EjbTimerPool - 2 > > > waiting to lock monitor 0x00000000221a3f88 (object > 0x00000006c1886f50, > > a > > > org.apache.openejb.util.classloader.URLClassLoaderFirst), > > > which is held by JmsResourceAdapter-worker- - 6 > > > JmsResourceAdapter-worker- - 6 > > > waiting for ownable synchronizer 0x00000006c13b0cc0, (a > > > java.util.concurrent.locks.ReentrantLock$NonfairSync), > > > which is held by JmsResourceAdapter-worker- - 7 > > > JmsResourceAdapter-worker- - 7 > > > waiting to lock monitor 0x00000000221a3f88 (object > 0x00000006c1886f50, > > a > > > org.apache.openejb.util.classloader.URLClassLoaderFirst), > > > which is held by JmsResourceAdapter-worker- - 6 > > > > > > Is there a way to get rid off the potential thread deadlock? > > > > > > Best regards, > > > Thomas > > > > > > > > > > > > -- > > > View this message in context: > > > > > > http://tomee-openejb.979440.n4.nabble.com/thread-deadlock-at-URLClassLoaderFirst-tp4674197.html > > > Sent from the TomEE Users mailing list archive at Nabble.com. > > > > > > > ________________________________ > > If you reply to this email, your message will be added to the discussion > > below: > > > > > http://tomee-openejb.979440.n4.nabble.com/thread-deadlock-at-URLClassLoaderFirst-tp4674197p4674198.html > > To unsubscribe from thread deadlock at URLClassLoaderFirst, click here< > > >. > > NAML< > > > http://tomee-openejb.979440.n4.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml > > > > > > > > > > > > > -- > > View this message in context: > > > http://tomee-openejb.979440.n4.nabble.com/thread-deadlock-at-URLClassLoaderFirst-tp4674197p4674222.html > > Sent from the TomEE Users mailing list archive at Nabble.com. > > > > ________________________________ > If you reply to this email, your message will be added to the discussion > below: > > http://tomee-openejb.979440.n4.nabble.com/thread-deadlock-at-URLClassLoaderFirst-tp4674197p4674223.html > To unsubscribe from thread deadlock at URLClassLoaderFirst, click here< > http://tomee-openejb.979440.n4.nabble.com/template/NamlServlet.jtp?macro=unsubscribe_by_code&node=4674197&code=dGhvbWFzLnNjaHVsZXJAb3BlbnRleHQuY29tfDQ2NzQxOTd8LTE4NTIyNTQ0OTI= > >. > NAML< > http://tomee-openejb.979440.n4.nabble.com/template/NamlServlet.jtp?macro=macro_viewer&id=instant_html%21nabble%3Aemail.naml&base=nabble.naml.namespaces.BasicNamespace-nabble.view.web.template.NabbleNamespace-nabble.view.web.template.NodeNamespace&breadcrumbs=notify_subscribers%21nabble%3Aemail.naml-instant_emails%21nabble%3Aemail.naml-send_instant_email%21nabble%3Aemail.naml > > > > > threaddump_restricted.tdump (13K) < > http://tomee-openejb.979440.n4.nabble.com/attachment/4674247/0/threaddump_restricted.tdump > > > > > > > -- > View this message in context: > http://tomee-openejb.979440.n4.nabble.com/thread-deadlock-at-URLClassLoaderFirst-tp4674197p4674247.html > Sent from the TomEE Users mailing list archive at Nabble.com. >
