Project: Eclipse_Platform_UI
Bug 122457 [Viewers] IllegalThreadStateException in BackgroundContentProvider
Reported: 2006-01-02 12:15:50 | Status: verified fixed

Since Eclipse 3.2M4 (it works unchanged with Eclipse 3.1.1), the DeferredContentProvider does not work as expected in my JFace dialog. Instead, an IllegalThreadStateException occures when a TableViewer's input is set in method "createDialogArea" of my "TitleAreaDialog" (see stack trace at the very end of this description). The source code that throws this exception is in method "makeDirty" in class BackgroundContentProvider. This method is called twice when the input of a TableViewer with a DeferredContentProvider changes (on "setLimit" and on "setFilter" in method "inputChanged"). "makeDirty" starts the sortThread - so when this method is called for the second time, the sortThread has already been started and maybe it has already terminated. In either case, makeDirty waits for the sortThread to die (sortThread.join()) before starting it. But according to the JDK API Specs, it is illegal to start a thread twice! This seems to cause the IllegalThreadStateException! (See code and exception below) So even if I made a mistake somewhere in my code, in my point of view, "makeDirty" is not correctly implemented. <code> private void makeDirty() { sortMon.cancel(); // make sure the sort thread is not running try { sortThread.join(); } catch (InterruptedException e) { Thread.currentThread().interrupt(); } /* MW: Create a new Thread object here??? */ sortThread.start(); } </code> <exception> java.lang.IllegalThreadStateException at java.lang.Thread.start(Unknown Source) at org.eclipse.jface.viewers.deferred.BackgroundContentProvider.makeDirty(BackgroundContentProvider.java:460) at org.eclipse.jface.viewers.deferred.BackgroundContentProvider.setContents(BackgroundContentProvider.java:490) at org.eclipse.jface.viewers.deferred.BackgroundContentProvider.access$2(BackgroundContentProvider.java:488) at org.eclipse.jface.viewers.deferred.BackgroundContentProvider$1.setContents(BackgroundContentProvider.java:110) at com.dgr.profi.stamm.ui.dialogs.StammdatenSearchDialog$ListConcurrentModel.requestUpdate(StammdatenSearchDialog.java:50) at org.eclipse.jface.viewers.deferred.BackgroundContentProvider.refresh(BackgroundContentProvider.java:174) at org.eclipse.jface.viewers.deferred.BackgroundContentProvider.setFilter(BackgroundContentProvider.java:406) at org.eclipse.jface.viewers.deferred.DeferredContentProvider.inputChanged(DeferredContentProvider.java:149) at org.eclipse.jface.viewers.ContentViewer.setInput(ContentViewer.java:245) at org.eclipse.jface.viewers.StructuredViewer.setInput(StructuredViewer.java:1417) at com.dgr.profi.stamm.ui.dialogs.KundeSearchDialog.createResultArea(KundeSearchDialog.java:196) at com.dgr.profi.stamm.ui.dialogs.StammdatenSearchDialog.createContentArea(StammdatenSearchDialog.java:98) at com.dgr.profi.ui.dialogs.RunnableContextDialog.createDialogArea(RunnableContextDialog.java:138) at org.eclipse.jface.dialogs.TitleAreaDialog.createContents(TitleAreaDialog.java:157) at org.eclipse.jface.window.Window.create(Window.java:417) at org.eclipse.jface.dialogs.Dialog.create(Dialog.java:1051) at org.eclipse.jface.window.Window.open(Window.java:775) at com.dgr.profi.stamm.internal.ui.ShowKundenSearchDialog.run(ShowKundenSearchDialog.java:38) at org.eclipse.ui.internal.PluginAction.runWithEvent(PluginAction.java:251) ...more lines skipped... </exception>

Files changed in fix:
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/deferred/BackgroundContentProvider.java