diff options
| -rw-r--r-- | org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/stringsubstitution/SelectedResourceManager.java | 131 |
1 files changed, 101 insertions, 30 deletions
diff --git a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/stringsubstitution/SelectedResourceManager.java b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/stringsubstitution/SelectedResourceManager.java index 352a8d6cf..2df6c515a 100644 --- a/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/stringsubstitution/SelectedResourceManager.java +++ b/org.eclipse.debug.ui/ui/org/eclipse/debug/internal/ui/stringsubstitution/SelectedResourceManager.java @@ -13,9 +13,20 @@ *******************************************************************************/ package org.eclipse.debug.internal.ui.stringsubstitution; +import java.lang.management.ManagementFactory; +import java.lang.management.ThreadInfo; import java.util.Iterator; +import java.util.concurrent.Callable; +import java.util.concurrent.ExecutorService; +import java.util.concurrent.Executors; +import java.util.concurrent.FutureTask; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.TimeoutException; +import java.util.concurrent.atomic.AtomicReference; import org.eclipse.core.resources.IResource; +import org.eclipse.core.runtime.IStatus; +import org.eclipse.core.runtime.MultiStatus; import org.eclipse.core.runtime.Platform; import org.eclipse.debug.internal.ui.DebugUIPlugin; import org.eclipse.jface.text.ITextSelection; @@ -23,6 +34,7 @@ import org.eclipse.jface.viewers.ISelection; import org.eclipse.jface.viewers.ISelectionProvider; import org.eclipse.jface.viewers.IStructuredSelection; import org.eclipse.jface.viewers.StructuredSelection; +import org.eclipse.swt.widgets.Display; import org.eclipse.ui.IEditorPart; import org.eclipse.ui.IEditorSite; import org.eclipse.ui.IWorkbenchPage; @@ -37,9 +49,16 @@ import org.eclipse.ui.IWorkbenchWindow; */ public class SelectedResourceManager { + // Limit in seconds to wait on UI for accessing data + private static final int MAX_UI_WAIT_TIME = 10; + // singleton private static SelectedResourceManager fgDefault; + // Used to avoid deadlocks while accessing UI thread from non UI code + private static ExecutorService executor = Executors.newSingleThreadExecutor(); + + /** * Returns the singleton resource selection manager * @@ -69,14 +88,11 @@ public class SelectedResourceManager { * @since 3.3 */ public IStructuredSelection getCurrentSelection() { - if(DebugUIPlugin.getStandardDisplay().getThread().equals(Thread.currentThread())) { - return getCurrentSelection0(); - } - else { - final IStructuredSelection[] selection = new IStructuredSelection[1]; - DebugUIPlugin.getStandardDisplay().syncExec(() -> selection[0] = getCurrentSelection0()); - return selection[0]; + IStructuredSelection selection = getFromUI(this::getCurrentSelection0); + if (selection == null) { + selection = StructuredSelection.EMPTY; } + return selection; } /** @@ -85,7 +101,7 @@ public class SelectedResourceManager { * * @since 3.4 */ - private IStructuredSelection getCurrentSelection0() { + IStructuredSelection getCurrentSelection0() { IWorkbenchWindow window = DebugUIPlugin.getActiveWorkbenchWindow(); if(window != null) { IWorkbenchPage page = window.getActivePage(); @@ -119,14 +135,8 @@ public class SelectedResourceManager { * @return selected resource or <code>null</code> */ public IResource getSelectedResource() { - if(DebugUIPlugin.getStandardDisplay().getThread().equals(Thread.currentThread())) { - return getSelectedResource0(); - } - else { - final IResource[] resource = new IResource[1]; - DebugUIPlugin.getStandardDisplay().syncExec(() -> resource[0] = getSelectedResource0()); - return resource[0]; - } + IResource resource = getFromUI(this::getSelectedResource0); + return resource; } /** @@ -177,14 +187,8 @@ public class SelectedResourceManager { * @return the current text selection as a <code>String</code> or <code>null</code> */ public String getSelectedText() { - if(DebugUIPlugin.getStandardDisplay().getThread().equals(Thread.currentThread())) { - return getSelectedText0(); - } - else { - final String[] text = new String[1]; - DebugUIPlugin.getStandardDisplay().syncExec(() -> text[0] = getSelectedText0()); - return text[0]; - } + String text = getFromUI(this::getSelectedText0); + return text; } /** @@ -224,14 +228,81 @@ public class SelectedResourceManager { * @since 3.2 */ public IWorkbenchWindow getActiveWindow() { - if(DebugUIPlugin.getStandardDisplay().getThread().equals(Thread.currentThread())) { - return DebugUIPlugin.getActiveWorkbenchWindow(); + IWorkbenchWindow window = getFromUI(DebugUIPlugin::getActiveWorkbenchWindow); + return window; + } + + private <T> T getFromUI(Callable<T> call) { + try { + if (Display.getCurrent() != null) { + return call.call(); + } else { + return runInUIThreadWithTimeout(call, MAX_UI_WAIT_TIME, TimeUnit.SECONDS); + } + } catch (TimeoutException e) { + reportTimeout(); + return null; + } catch (Exception e) { + DebugUIPlugin.log(e); + return null; } - else { - final IWorkbenchWindow[] window = new IWorkbenchWindow[1]; - DebugUIPlugin.getStandardDisplay().syncExec(() -> window[0] = DebugUIPlugin.getActiveWorkbenchWindow()); - return window[0]; + } + + /** + * Tries to run the task in the UI thread, and gives up if UI thread does not + * answer after given timeout + * + * @param timeout to wait for the UI lock + * @return may return null + * @throws Exception + */ + static <V> V runInUIThreadWithTimeout(Callable<V> callable, long timeout, TimeUnit units) throws Exception { + FutureTask<V> task = new FutureTask<>(() -> syncExec(callable)); + executor.execute(task); + return task.get(timeout, units); + } + + static <V> V syncExec(Callable<V> callable) throws Exception { + AtomicReference<V> ref = new AtomicReference<>(); + AtomicReference<Exception> ex = new AtomicReference<>(); + DebugUIPlugin.getStandardDisplay().syncExec(() -> { + try { + ref.set(callable.call()); + } catch (Exception e) { + ex.set(e); + } + }); + if (ex.get() != null) { + throw ex.get(); } + return ref.get(); } + /** + * Reports an error the log with thread stack information for current and UI threads + */ + private static void reportTimeout() { + Thread nonUiThread = Thread.currentThread(); + + String msg = "To avoid deadlock while executing Display.syncExec() from a non UI thread '" //$NON-NLS-1$ + + nonUiThread.getName() + "', operation was cancelled."; //$NON-NLS-1$ + MultiStatus main = new MultiStatus(DebugUIPlugin.getUniqueIdentifier(), IStatus.ERROR, msg, null); + + ThreadInfo[] threads = ManagementFactory.getThreadMXBean().getThreadInfo( + new long[] { nonUiThread.getId(), Display.getDefault().getThread().getId() }, true, true); + + for (ThreadInfo info : threads) { + String childMsg; + if (info.getThreadId() == nonUiThread.getId()) { + childMsg = nonUiThread.getName() + " thread probably holding a lock and trying to acquire UI lock"; //$NON-NLS-1$ + } else { + childMsg = "UI thread waiting on a job or lock."; //$NON-NLS-1$ + } + Exception childEx = new IllegalStateException("Call stack for thread " + info.getThreadName()); //$NON-NLS-1$ + childEx.setStackTrace(info.getStackTrace()); + main.add(DebugUIPlugin.newErrorStatus(childMsg, childEx)); + } + + DebugUIPlugin.log(main); + } } |