HashMap should never be invoked without synchronization if there is a chance that it may be accessed by different threads.
Thread [Worker-0] (Suspended)
HashMap<K,V>.get(Object) line: 320
JarAccessFactory.getJarAccess(String, JarSystemImpl) line: 11
JarSystemImpl.getJarAccess() line: 32
JarSystemImpl.getChildByPathPart(String) line: 74
JarSystemImpl(XModelObjectImpl).getChildByPath(String) line: 334
TaglibMapping.findTldsInJar(XModelObject) line: 225
TaglibMapping.findTldsInJars() line: 209
TaglibMapping.revalidate(XModelObject) line: 85
JSFWatcherContributor.updateProject() line: 49
Watcher.updateAll() line: 106
Watcher.access$0(Watcher) line: 89
Watcher$WatcherRunnable.run() line: 47
XJob.runInWorkspace(IProgressMonitor) line: 178
XJob(InternalWorkspaceJob).run(IProgressMonitor) line: 38
Worker.run() line: 54
Thread [Worker-7] (Suspended)
HashMap<K,V>.get(Object) line: 320
JarAccessFactory.getJarAccess(String, JarSystemImpl) line: 11
JarSystemImpl.getJarAccess() line: 32
JarSystemImpl.getChildByPathPart(String) line: 74
JarSystemImpl(XModelObjectImpl).getChildByPath(String) line: 334
ClassPathMonitor.process() line: 68
JSF2ProjectBuilder.build(int, Map<String,String>, IProgressMonitor) line: 101
KbBuilder.buildExtensionModels(int, Map, IProgressMonitor) line: 191
KbBuilder.build(int, Map<String,String>, IProgressMonitor) line: 136
BuildManager$2.run() line: 728
SafeRunner.run(ISafeRunnable) line: 42
BuildManager.basicBuild(int, IncrementalProjectBuilder, Map<String,String>, MultiStatus, IProgressMonitor) line: 199
BuildManager.basicBuild(IBuildConfiguration, int, IBuildContext, ICommand[], MultiStatus, IProgressMonitor) line: 239
BuildManager$1.run() line: 292
SafeRunner.run(ISafeRunnable) line: 42
BuildManager.basicBuild(IBuildConfiguration, int, IBuildContext, MultiStatus, IProgressMonitor) line: 295
BuildManager.basicBuildLoop(IBuildConfiguration[], IBuildConfiguration[], int, MultiStatus, IProgressMonitor) line: 351
BuildManager.build(IBuildConfiguration[], IBuildConfiguration[], int, IProgressMonitor) line: 374
AutoBuildJob.doBuild(IProgressMonitor) line: 143
AutoBuildJob.run(IProgressMonitor) line: 241
Worker.run() line: 54