Hello! It's a very specific corner case. Please create a JIRA ticket and I'll try to fix it. Thanks for posting and investigating!
On Thu, Jul 30, 2020 at 1:44 PM Oliver Kaiser <oliver.kai...@eddyson.de> wrote: > Hi everyone, > > > we recently found a strange deadlock problem; first seemed to be related > to switching from 5.5.0-beta-1 to 5.5.0, at least > in the full application it was easy to reproduce with the latter but (in > a few manual tests) not with the beta. > > after trying to reduce it to a minimal test case… it can be triggered > with either (and 5.4.x); maybe in the "real" code the calls > take long enough to avoid the data race or at least make it unlikely. > > > on to the questions: > > * has anyone seen something like this before? closest bug i can find is: > https://issues.apache.org/jira/browse/TAPESTRY-2561 > > * is this likely related to registry startup? kinda afraid of same > situation during normal operations, though once most/all services > are realized everything should be fine > > thanks for reading & any hints you can offer > > Regards, > Oliver > > > it appears all of the following is required: > > * a builder method for a simple class (not a service); with some kind of > call to IOC (inject anything) > > public static SomeClass build(@Inject @Symbol("some.symbol") String > uri) { > return new SomeClass(); > } > > > * this class is a dependency for a shared service: > > public class SharedImpl implements Shared { > > public SharedImpl(SomeClass iDoNothing) { > } > > > * two services marked as eager-load; both require the shared service > > public static void bind(ServiceBinder binder) { > binder.bind(JobAdder.class, JobAdderImpl.class).eagerLoad(); > binder.bind(Other.class, OtherImpl.class).eagerLoad(); > binder.bind(Shared.class, SharedImpl.class); > } > > > * JobAdder c-tor adds Runnable(s) to PeriodicExecutor > > public JobAdderImpl(List<RunnableJobData> parts, PeriodicExecutor exec) > { > LOG.info("Blocked here?"); > > for (RunnableJobData p : parts) { > exec.addJob(new ImmediateStartIntervalSchedule(1000 * 60), > p.name, p.run); > } > } > > > * the Runnable and OtherImpl (c-tor) call the shared service (instances > are realized) > > @Contribute(JobAdder.class) > public static void contributeJobParts(OrderedConfiguration conf, > Shared something) { > > conf.add("abc", new RunnableJobData("abc", () -> { > LOG.info("starting job"); > something.doFoo(); > > > public class OtherImpl implements Other { > > public OtherImpl(Shared xx) { > xx.doFoo(); > > > * the jobs start immediately (no initial delay) > > public class ImmediateStartIntervalSchedule extends IntervalSchedule { > > public ImmediateStartIntervalSchedule(final long interval) { > super(interval); > } > > @Override > public long firstExecution() { > return System.currentTimeMillis(); > } > > > > probably the easiest fix (for us) is to avoid the immediate execution of > periodic jobs while "RegistryImpl.performRegistryStartup" > is still running on the main thread; e.g. adding the jobs from a > @Startup method seems to work ok > > maybe PeriodicExecutorImpl::start should be called from @Startup instead > of @PostInjection (assuming startup methods are called after the > registry is done, while @PostInjection is called earlier?) > > > in the trace below both threads "hold" a R-lock, one also has (upgraded > to) W, the second blocks on W … that seems wrong > > > https://github.com/apache/tapestry-5/blob/master/tapestry-ioc/src/main/java/org/apache/tapestry5/ioc/internal/util/ConcurrentBarrier.java#L54 > maybe reentrancy; but i'm not sure about the "upgrade R to W" logic > > > > here is the test source: https://easyupload.io/xzy6j1 > > > Found one Java-level deadlock: > ============================= > "main": > waiting to lock monitor 0x00007f7f38008b80 (object > 0x000000071554f4a8, a > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator), > which is held by "Tapestry PeriodicExecutor" > "Tapestry PeriodicExecutor": > waiting for ownable synchronizer 0x0000000716130940, (a > java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync), > which is held by "main" > > > "main": > at > > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator.obtainObjectFromCreator(JustInTimeObjectCreator.java:62) > - waiting to lock <0x000000071554f4a8> (a > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator) > at > > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator.createObject(JustInTimeObjectCreator.java:55) > at $SymbolSource_c9319bed00c.delegate(Unknown Source) > at $SymbolSource_c9319bed00c.valueForSymbol(Unknown Source) > at > > org.apache.tapestry5.ioc.internal.services.SymbolObjectProvider.provide(SymbolObjectProvider.java:50) > … > at > org.apache.tapestry5.ioc.internal.ModuleImpl$1.invoke(ModuleImpl.java:198) > at > > org.apache.tapestry5.ioc.internal.util.ConcurrentBarrier.withWrite(ConcurrentBarrier.java:139) > at > org.apache.tapestry5.ioc.internal.ModuleImpl$2.invoke(ModuleImpl.java:215) > at > > org.apache.tapestry5.ioc.internal.util.ConcurrentBarrier.withRead(ConcurrentBarrier.java:83) > at > > org.apache.tapestry5.ioc.internal.ModuleImpl.findOrCreate(ModuleImpl.java:221) > at > > org.apache.tapestry5.ioc.internal.ModuleImpl.getService(ModuleImpl.java:112) > > … > at > > org.apache.tapestry5.ioc.internal.AbstractReloadableObjectCreator.createObject(AbstractReloadableObjectCreator.java:118) > - locked <0x00000007154d53f8> (a > > org.apache.tapestry5.ioc.internal.ReloadableServiceImplementationObjectCreator) > at $Shared_c9319bed012.delegate(Unknown Source) > at $Shared_c9319bed012.doFoo(Unknown Source) > at $Shared_c9319bed00e.doFoo(Unknown Source) > at de.eddyson.t5.deadlock.OtherImpl.<init>(OtherImpl.java:8) > … > at > > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator.obtainObjectFromCreator(JustInTimeObjectCreator.java:67) > - locked <0x00000007156584b0> (a > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator) > at > > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator.createObject(JustInTimeObjectCreator.java:55) > at > > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator.eagerLoadService(JustInTimeObjectCreator.java:88) > at > > org.apache.tapestry5.ioc.internal.RegistryImpl.performRegistryStartup(RegistryImpl.java:357) > at > > org.apache.tapestry5.ioc.internal.RegistryWrapper.performRegistryStartup(RegistryWrapper.java:89) > > > > "Tapestry PeriodicExecutor": > at jdk.internal.misc.Unsafe.park(java.base@11.0.8/Native Method) > - parking to wait for <0x0000000716130940> (a > java.util.concurrent.locks.ReentrantReadWriteLock$NonfairSync) > at > java.util.concurrent.locks.LockSupport.park(java.base@11.0.8 > /LockSupport.java:194) > at > > java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(java.base@11.0.8 > /AbstractQueuedSynchronizer.java:885) > at > > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(java.base@11.0.8 > /AbstractQueuedSynchronizer.java:917) > at > > java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(java.base@11.0.8 > /AbstractQueuedSynchronizer.java:1240) > at > > java.util.concurrent.locks.ReentrantReadWriteLock$WriteLock.lock(java.base@11.0.8 > /ReentrantReadWriteLock.java:959) > at > > org.apache.tapestry5.ioc.internal.util.ConcurrentBarrier.withWrite(ConcurrentBarrier.java:135) > at > org.apache.tapestry5.ioc.internal.ModuleImpl$2.invoke(ModuleImpl.java:215) > at > > org.apache.tapestry5.ioc.internal.util.ConcurrentBarrier.withRead(ConcurrentBarrier.java:83) > at > > org.apache.tapestry5.ioc.internal.ModuleImpl.findOrCreate(ModuleImpl.java:221) > at > > org.apache.tapestry5.ioc.internal.ModuleImpl.getService(ModuleImpl.java:112) > at > > org.apache.tapestry5.ioc.internal.RegistryImpl.getService(RegistryImpl.java:497) > … > - locked <0x000000071554f4a8> (a > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator) > at > > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator.createObject(JustInTimeObjectCreator.java:55) > at $SymbolSource_c9319bed00c.delegate(Unknown Source) > at $SymbolSource_c9319bed00c.valueForSymbol(Unknown Source) > at > > org.apache.tapestry5.ioc.internal.services.SymbolObjectProvider.provide(SymbolObjectProvider.java:50) > … > at > > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator.obtainObjectFromCreator(JustInTimeObjectCreator.java:67) > - locked <0x000000071548fd68> (a > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator) > at > > org.apache.tapestry5.ioc.internal.services.JustInTimeObjectCreator.createObject(JustInTimeObjectCreator.java:55) > at $ParallelExecutor_c9319bed010.delegate(Unknown Source) > at $ParallelExecutor_c9319bed010.invoke(Unknown Source) > at > > org.apache.tapestry5.ioc.internal.services.cron.PeriodicExecutorImpl$Job.start(PeriodicExecutorImpl.java:181) > at > > org.apache.tapestry5.ioc.internal.services.cron.PeriodicExecutorImpl.executeCurrentBatch(PeriodicExecutorImpl.java:382) > at > > org.apache.tapestry5.ioc.internal.services.cron.PeriodicExecutorImpl.run(PeriodicExecutorImpl.java:315) > > --------------------------------------------------------------------- > To unsubscribe, e-mail: users-unsubscr...@tapestry.apache.org > For additional commands, e-mail: users-h...@tapestry.apache.org > > -- Thiago
