Details
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Bug
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Resolution: Done
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Blocker
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8.0.0.Beta1
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None
Description
ModuleSpecification does not use any form of synchronization to protect its mutable state yet may be used from multiple threads in multi-module deployment when a DeploymentUnitProcessor touches ModuleSpecification of a different deployment unit which is processed at that moment.
Here is an example of such access: https://github.com/wildfly/wildfly/blob/master/jsf/subsystem/src/main/java/org/jboss/as/jsf/deployment/JSFDependencyProcessor.java#L93
Here's how I think this problem manifests:
Caused by: java.lang.NullPointerException
at org.jboss.as.server.deployment.module.ModuleSpecProcessor.createDependencies(ModuleSpecProcessor.java:284) [wildfly-server-8.0.0.Beta2-SNAPSHOT.jar:8.0.0.Beta2-SNAPSHOT]
at org.jboss.as.server.deployment.module.ModuleSpecProcessor.createModuleService(ModuleSpecProcessor.java:220) [wildfly-server-8.0.0.Beta2-SNAPSHOT.jar:8.0.0.Beta2-SNAPSHOT]
at org.jboss.as.server.deployment.module.ModuleSpecProcessor.deployModuleSpec(ModuleSpecProcessor.java:125) [wildfly-server-8.0.0.Beta2-SNAPSHOT.jar:8.0.0.Beta2-SNAPSHOT]
at org.jboss.as.server.deployment.module.ModuleSpecProcessor.deploy(ModuleSpecProcessor.java:88) [wildfly-server-8.0.0.Beta2-SNAPSHOT.jar:8.0.0.Beta2-SNAPSHOT]
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:159) [wildfly-server-8.0.0.Beta2-SNAPSHOT.jar:8.0.0.Beta2-SNAPSHOT]
... 5 more
and here's my attempt to verify concurrent access by changing the code slightly to deadlock on concurrent access:
"MSC service thread 1-6":
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000f742ba28> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:867)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197)
at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:214)
at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:290)
at org.jboss.as.server.deployment.module.ModuleSpecification.foo(ModuleSpecification.java:170)
at org.jboss.as.server.deployment.module.ModuleSpecification.addSystemDependency(ModuleSpecification.java:121)
at org.jboss.as.jsf.deployment.JSFDependencyProcessor.addJSFAPI(JSFDependencyProcessor.java:115)
at org.jboss.as.jsf.deployment.JSFDependencyProcessor.deploy(JSFDependencyProcessor.java:93)
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:159)
- locked <0x00000000f69a8e88> (a org.jboss.as.server.deployment.DeploymentUnitPhaseService)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1944)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1877)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)
"MSC service thread 1-3":
at sun.misc.Unsafe.park(Native Method)
- parking to wait for <0x00000000f742ba58> (a java.util.concurrent.locks.ReentrantLock$NonfairSync)
at java.util.concurrent.locks.LockSupport.park(LockSupport.java:186)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:834)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:867)
at java.util.concurrent.locks.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1197)
at java.util.concurrent.locks.ReentrantLock$NonfairSync.lock(ReentrantLock.java:214)
at java.util.concurrent.locks.ReentrantLock.lock(ReentrantLock.java:290)
at org.jboss.as.server.deployment.module.ModuleSpecification.foo(ModuleSpecification.java:175)
at org.jboss.as.server.deployment.module.ModuleSpecification.addSystemDependency(ModuleSpecification.java:121)
at org.jboss.as.jsf.deployment.JSFDependencyProcessor.addJSFAPI(JSFDependencyProcessor.java:115)
at org.jboss.as.jsf.deployment.JSFDependencyProcessor.deploy(JSFDependencyProcessor.java:93)
at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:159)
- locked <0x00000000f6782960> (a org.jboss.as.server.deployment.DeploymentUnitPhaseService)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.startService(ServiceControllerImpl.java:1944)
at org.jboss.msc.service.ServiceControllerImpl$StartTask.run(ServiceControllerImpl.java:1877)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:744)