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I20040514 (with org.eclipse.ui.workbench from HEAD): A Self-hosted workspace is not responding because, according to the Threads and Monitors view, there is a deadlock condition. Here are all the stack frames, copied from the Debug view: org.eclipse.core.launcher.Main at localhost:3934 (Suspended) System Thread [Finalizer] (Suspended) Object.wait(long) line: not available [native method] ReferenceQueue.remove(long) line: not available ReferenceQueue.remove() line: not available Finalizer$FinalizerThread.run() line: not available System Thread [Reference Handler] (Suspended) Object.wait(long) line: not available [native method] Reference$Lock(Object).wait() line: not available Reference$ReferenceHandler.run() line: not available Thread [main] (Suspended) JobManager.endJob(InternalJob, IStatus, boolean) line: 392 ProgressViewUpdater$1(InternalJob).done(IStatus) line: 134 ProgressViewUpdater$1(Job).done(IStatus) line: 202 UIJob$1.run() line: 101 RunnableLock.run() line: 35 UISynchronizer(Synchronizer).runAsyncMessages() line: 106 Display.runAsyncMessages() line: 2702 Display.readAndDispatch() line: 2394 Workbench.runEventLoop(Window$IExceptionHandler, Display) line: 1363 Workbench.runUI() line: 1334 Workbench.createAndRunWorkbench(Display, WorkbenchAdvisor) line: 253 PlatformUI.createAndRunWorkbench(Display, WorkbenchAdvisor) line: 141 IDEApplication.run(Object) line: 90 PlatformActivator$1.run(Object) line: 298 EclipseStarter.run(Object) line: 249 EclipseStarter.run(String[], Runnable) line: 126 NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method] NativeMethodAccessorImpl.invoke(Object, Object[]) line: not available DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: not available Method.invoke(Object, Object[]) line: not available Main.basicRun(String[]) line: 269 Main.run(String[]) line: 722 Main.main(String[]) line: 706 System Thread [Signal Dispatcher] (Suspended) Thread [Framework Event Dispatcher] (Suspended) Object.wait(long) line: not available [native method] EventThread(Object).wait() line: not available EventThread.getNextEvent() line: 149 EventThread.run() line: 107 Thread [Start Level Event Dispatcher] (Suspended) Object.wait(long) line: not available [native method] EventThread(Object).wait() line: not available EventThread.getNextEvent() line: 149 EventThread.run() line: 107 Thread [Thread-0] (Suspended) Object.wait(long) line: not available [native method] ReferenceQueue.remove(long) line: not available ReferenceQueue.remove() line: not available ActionContributionItem$ImageCache$ReferenceCleanerThread.run() line: 196 Thread [Thread-1] (Suspended) Object.wait(long) line: not available [native method] ReferenceQueue.remove(long) line: not available ReferenceQueue.remove() line: not available ActionContributionItem$ImageCache$ReferenceCleanerThread.run() line: 196 Thread [Worker-0] (Suspended) JobManager.findBlockingJob(InternalJob) line: 452 ThreadJob.joinRun(IProgressMonitor) line: 152 ImplicitJobs.begin(ISchedulingRule, IProgressMonitor, boolean) line: 87 JobManager.beginRule(ISchedulingRule, IProgressMonitor) line: 167 WorkManager.checkIn(ISchedulingRule, IProgressMonitor) line: 95 Workspace.prepareOperation(ISchedulingRule, IProgressMonitor) line: 1629 Workspace.run(IWorkspaceRunnable, ISchedulingRule, int, IProgressMonitor) line: 1669 Workspace.run(IWorkspaceRunnable, IProgressMonitor) line: 1694 JavaCore$4.run(IProgressMonitor) line: 3644 Worker.run() line: 66 Thread [Java indexing] (Suspended) JobManager.setPriority(InternalJob, int) line: 839 JobManager$1$ProgressJob(InternalJob).setPriority(int) line: 346 JobManager$1$ProgressJob(Job).setPriority(int) line: 440 IndexManager(JobManager).run() line: 363 Thread.run() line: not available Thread [Worker-1] (Suspended) JobManager.runNow(InternalJob) line: 747 ThreadJob.joinRun(IProgressMonitor) line: 149 ImplicitJobs.begin(ISchedulingRule, IProgressMonitor, boolean) line: 87 JobManager.beginRule(ISchedulingRule, IProgressMonitor) line: 167 LastSaveReferenceProvider.readDocument(IProgressMonitor, boolean) line: 225 LastSaveReferenceProvider.getReference(IProgressMonitor) line: 111 DocumentLineDiffer$1.run(IProgressMonitor) line: 370 Worker.run() line: 66 Thread [Worker-2] (Suspended) ProgressManager.refreshJobInfo(JobInfo) line: 526 ProgressManager$JobMonitor.beginTask(String, int) line: 186 DecorationScheduler$1.run(IProgressMonitor) line: 220 Worker.run() line: 66 Thread [Worker-3] (Suspended) ProgressManager.refreshJobInfo(JobInfo) line: 526 ProgressManager$JobMonitor.subTask(String) line: 270 JobManager$1$ProgressJob.run(IProgressMonitor) line: 319 Worker.run() line: 66 Thread [Worker-4] (Suspended) Object.wait(long) line: not available [native method] Semaphore.acquire(long) line: 38 JobManager.join(InternalJob) line: 514 TableContentProvider$1(InternalJob).join() line: 271 TableContentProvider$1(Job).join() line: 353 TableContentProvider.doUpdate(IProgressMonitor) line: 353 TableContentProvider.access$4(TableContentProvider, IProgressMonitor) line: 346 TableContentProvider$3.run(IProgressMonitor) line: 184 RestartableJob$2.run(IProgressMonitor) line: 86 Worker.run() line: 66 Thread [Worker-5] (Suspended) ProgressManager.refreshJobInfo(JobInfo) line: 526 JobInfo.cancel() line: 307 ProgressManager$JobMonitor.setCanceled(boolean) line: 236 JobManager.cancel(InternalJob) line: 183 RestartableJob$2(InternalJob).cancel() line: 122 RestartableJob$2(Job).cancel() line: 183 RestartableJob.cancel() line: 152 TableContentProvider.cancelPendingChanges() line: 336 ProblemView(TableView).haltTableUpdates() line: 92 ProblemView(MarkerView).internalRefresh(IProgressMonitor) line: 155 MarkerView.access$2(MarkerView, IProgressMonitor) line: 151 MarkerView$3.run(IProgressMonitor) line: 237 RestartableJob$2.run(IProgressMonitor) line: 86 Worker.run() line: 66 Thread [Worker-6] (Suspended) JobManager.setPriority(InternalJob, int) line: 839 ThreadJob(InternalJob).setPriority(int) line: 346 ThreadJob(Job).setPriority(int) line: 440 ThreadJob.<init>(JobManager, ISchedulingRule) line: 57 ImplicitJobs.newThreadJob(ISchedulingRule) line: 158 ImplicitJobs.begin(ISchedulingRule, IProgressMonitor, boolean) line: 67 JobManager.beginRule(ISchedulingRule, IProgressMonitor) line: 167 WorkManager.checkIn(ISchedulingRule, IProgressMonitor) line: 95 Workspace.prepareOperation(ISchedulingRule, IProgressMonitor) line: 1629 AutoBuildJob.doBuild(IProgressMonitor) line: 146 AutoBuildJob.run(IProgressMonitor) line: 196 Worker.run() line: 66 Thread [Worker-7] (Suspended) JobManager.nextJob() line: 647 JobManager.startJob() line: 936 WorkerPool.startJob(Worker) line: 237 Worker.run() line: 59 Thread [Worker-8] (Suspended) JobManager.schedule(InternalJob, long) line: 769 ProgressViewUpdater$1(InternalJob).schedule(long) line: 313 ProgressViewUpdater$1(Job).schedule(long) line: 417 ProgressViewUpdater.scheduleUpdate() line: 197 ProgressViewUpdater.refreshJobInfo(JobInfo) line: 302 ProgressManager.refreshJobInfo(JobInfo) line: 531 ProgressManager$1.aboutToRun(IJobChangeEvent) line: 344 JobListeners$1.notify(IJobChangeListener, IJobChangeEvent) line: 34 JobListeners.doNotify(JobListeners$IListenerDoit, IJobChangeEvent) line: 101 JobListeners.aboutToRun(Job) line: 151 JobManager.startJob() line: 942 WorkerPool.startJob(Worker) line: 230 Worker.run() line: 59 Thread [Worker-9] (Suspended) JobManager.nextJob() line: 647 JobManager.startJob() line: 936 WorkerPool.startJob(Worker) line: 230 Worker.run() line: 59 Thread [All Types Caching] (Suspended) Thread.sleep(long) line: not available [native method] IndexManager(JobManager).performConcurrentJob(IJob, int, IProgressMonitor) line: 243 SearchEngine.searchAllTypeNames(IWorkspace, char[], char[], int, boolean, int, IJavaSearchScope, ITypeNameRequestor, int, IProgressMonitor) line: 865 AllTypesCache.search(ITypeNameRequestor, int, IProgressMonitor) line: 519 AllTypesCache$TypeCacher.doSearchTypes() line: 188 AllTypesCache$TypeCacher.run() line: 157 Unfortunately the Threads and Monitors view doesn't support copy (!). So I'll attach screenshots shortly.
Created attachment 10677 [details] Deadlock view
Created attachment 10678 [details] Threads view
This deadlock was introduced by new locking code within the progress monitor setCanceled() callback from core to UI (ProgressManager.refreshJobInfo). I will refactor JobManager to avoid owning the job manager lock while calling the progress monitor. Tod, this new code pattern in ProgressManager is very deadlock prone. It holds a lock while calling progress listeners, which may in turn acquire arbitrary locks (or syncExec). A safer approach is to create a copy of the listener list within the sync block, and then notify listeners outside the sync block. Alternatively, use the org.eclipse.jface.util.ListenerList, which Nick is about to release thread safety fixes for.
I have fixed this deadlock by avoiding calling the progress monitor inside the job manager sync block. However, the ProgressManager code also needs to be fixed. Users of jobs will not be expecting thread safety issues while calling IProgressMonitor methods. If they do call the progress monitor while holding a lock at the moment, deadlock is likely. Again, using ListenerList, or creating a copy of the listeners and then calling them outside the sync block is recommended.
I have made the suggested changes and released them (thanks once again John). I have switched to doing a toArray() call and then iterating over the result as this will allocate a new array everytime. John if you could check that I have made the changes you think are neccessary I would be most appreciative.
Tod, your fix looks good.
