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Bug 351938

Summary:	ConcurrentModificationException in testTimerExecIsSerializable()
Product:	[RT] RAP	Reporter:	Holger Staudacher <holger.staudacher>
Component:	RWT	Assignee:	Project Inbox <rap-inbox>
Status:	RESOLVED FIXED	QA Contact:
Severity:	normal
Priority:	P3
Version:	1.5
Target Milestone:	---
Hardware:	All
OS:	All
Whiteboard:

Description Holger Staudacher

2011-07-13 06:05:06 EDT

Today I executed our tests and saw a red test with a ConcurrentModificationException.

The test was: org.eclipse.swt.widgets.DisplaySerialization_Test.testTimerExecIsSerializable()

Here is the stack trace:

java.util.ConcurrentModificationException
	at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:761)
	at java.util.LinkedList$ListItr.next(LinkedList.java:696)
	at org.eclipse.swt.widgets.TimerExecScheduler.rescheduleTasks(TimerExecScheduler.java:81)
	at org.eclipse.swt.widgets.TimerExecScheduler.access$2(TimerExecScheduler.java:78)
	at org.eclipse.swt.widgets.TimerExecScheduler$PostDeserializationValidation$1.run(TimerExecScheduler.java:133)
	at org.eclipse.rwt.internal.engine.PostDeserialization.runProcessors(PostDeserialization.java:27)
	at org.eclipse.rwt.internal.engine.RWTClusterSupport.beforeService(RWTClusterSupport.java:56)
	at org.eclipse.rwt.internal.engine.RWTClusterSupport.beforeService(RWTClusterSupport.java:47)
	at org.eclipse.rwt.internal.engine.RWTClusterSupport.doFilter(RWTClusterSupport.java:31)
	at org.eclipse.swt.widgets.DisplaySerialization_Test.runClusterSupportFilter(DisplaySerialization_Test.java:257)
	at org.eclipse.swt.widgets.DisplaySerialization_Test.testTimerExecIsSerializable(DisplaySerialization_Test.java:221)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	at java.lang.reflect.Method.invoke(Method.java:597)
	at junit.framework.TestCase.runTest(TestCase.java:164)
	at junit.framework.TestCase.runBare(TestCase.java:130)
	at junit.framework.TestResult$1.protect(TestResult.java:106)
	at junit.framework.TestResult.runProtected(TestResult.java:124)
	at junit.framework.TestResult.run(TestResult.java:109)
	at junit.framework.TestCase.run(TestCase.java:120)
	at junit.framework.TestSuite.runTest(TestSuite.java:230)
	at junit.framework.TestSuite.run(TestSuite.java:225)
	at junit.framework.TestSuite.runTest(TestSuite.java:230)
	at junit.framework.TestSuite.run(TestSuite.java:225)
	at org.eclipse.jdt.internal.junit.runner.junit3.JUnit3TestReference.run(JUnit3TestReference.java:130)
	at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
	at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Comment 1 Rüdiger Herrmann

2011-07-13 14:17:36 EDT

Access to the 'tasks' field from TimerExecScheduler#rescheduleTasks() was unsynchronized. This could lead to newly added tasks that are already being executed interfere with iterating over the list of tasks.
Guarded rescheduleTasks() with sync lock. Changes are in CVS HEAD.