NEW - bug 239182: blocked and queued synch jobs

https://bugs.eclipse.org/bugs/show_bug.cgi?id=239182

3 files changed, 121 insertions, 8 deletions

diff --git a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/data/TaskDataManager.java b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/data/TaskDataManager.java
index 642d7e829..c00993df4 100644
--- a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/data/TaskDataManager.java
+++ b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/data/TaskDataManager.java
@@ -109,6 +109,7 @@ public class TaskDataManager implements ITaskDataManager {
 		Assert.isNotNull(task);
 		final String kind = task.getConnectorKind();
 		final TaskDataState[] result = new TaskDataState[1];
+		final boolean[] changed = new boolean[1];
 		taskList.run(new ITaskListRunnable() {
 			public void execute(IProgressMonitor monitor) throws CoreException {
 				final File file = getMigratedFile(task, kind);
@@ -127,9 +128,11 @@ public class TaskDataManager implements ITaskDataManager {
 					case INCOMING:
 					case INCOMING_NEW:
 						task.setSynchronizationState(SynchronizationState.SYNCHRONIZED);
+						changed[0] = true;
 						break;
 					case CONFLICT:
 						task.setSynchronizationState(SynchronizationState.OUTGOING);
+						changed[0] = true;
 						break;
 					}
 					task.setMarkReadPending(true);
@@ -137,7 +140,9 @@ public class TaskDataManager implements ITaskDataManager {
 				result[0] = state;
 			}
 		});
-		taskList.notifyElementChanged(task);
+		if (changed[0]) {
+			taskList.notifyElementChanged(task);
+		}
 		return result[0];
 	}
 
@@ -145,6 +150,7 @@ public class TaskDataManager implements ITaskDataManager {
 		final AbstractTask task = (AbstractTask) itask;
 		Assert.isNotNull(task);
 		final String kind = task.getConnectorKind();
+		final boolean[] changed = new boolean[1];
 		taskList.run(new ITaskListRunnable() {
 			public void execute(IProgressMonitor monitor) throws CoreException {
 				final File file = getFile(task, kind);
@@ -152,11 +158,15 @@ public class TaskDataManager implements ITaskDataManager {
 				switch (task.getSynchronizationState()) {
 				case SYNCHRONIZED:
 					task.setSynchronizationState(SynchronizationState.OUTGOING);
+					changed[0] = true;
+					break;
 				}
 				taskList.addTask(task);
 			}
 		});
-		taskList.notifyElementChanged(task);
+		if (changed[0]) {
+			taskList.notifyElementChanged(task);
+		}
 	}
 
 	public void putUpdatedTaskData(final ITask itask, final TaskData taskData, final boolean user) throws CoreException {
@@ -267,6 +277,7 @@ public class TaskDataManager implements ITaskDataManager {
 		final AbstractTask task = (AbstractTask) itask;
 		Assert.isNotNull(task);
 		final String kind = task.getConnectorKind();
+		final TaskDataManagerEvent event = new TaskDataManagerEvent(this, itask);
 		taskList.run(new ITaskListRunnable() {
 			public void execute(IProgressMonitor monitor) throws CoreException {
 				File dataFile = getFile(task, kind);
@@ -276,15 +287,18 @@ public class TaskDataManager implements ITaskDataManager {
 				switch (task.getSynchronizationState()) {
 				case OUTGOING:
 					task.setSynchronizationState(SynchronizationState.SYNCHRONIZED);
+					event.setTaskChanged(true);
 					break;
 				case CONFLICT:
 					task.setSynchronizationState(SynchronizationState.INCOMING);
+					event.setTaskChanged(true);
 					break;
 				}
 			}
 		});
-		taskList.notifyElementChanged(task);
-		final TaskDataManagerEvent event = new TaskDataManagerEvent(this, itask);
+		if (event.getTaskChanged()) {
+			taskList.notifyElementChanged(task);
+		}
 		fireEditsDiscarded(event);
 	}
 
@@ -431,6 +445,7 @@ public class TaskDataManager implements ITaskDataManager {
 	public void setTaskRead(final ITask itask, final boolean read) {
 		final AbstractTask task = (AbstractTask) itask;
 		Assert.isNotNull(task);
+		final boolean changed[] = new boolean[1];
 		try {
 			taskList.run(new ITaskListRunnable() {
 				public void execute(IProgressMonitor monitor) throws CoreException {
@@ -440,10 +455,12 @@ public class TaskDataManager implements ITaskDataManager {
 						case INCOMING_NEW:
 							task.setSynchronizationState(SynchronizationState.SYNCHRONIZED);
 							task.setMarkReadPending(true);
+							changed[0] = true;
 							break;
 						case CONFLICT:
 							task.setSynchronizationState(SynchronizationState.OUTGOING);
 							task.setMarkReadPending(true);
+							changed[0] = true;
 							break;
 						}
 					} else {
@@ -451,6 +468,7 @@ public class TaskDataManager implements ITaskDataManager {
 						case SYNCHRONIZED:
 							task.setSynchronizationState(SynchronizationState.INCOMING);
 							task.setMarkReadPending(false);
+							changed[0] = true;
 							break;
 						}
 					}
@@ -460,7 +478,9 @@ public class TaskDataManager implements ITaskDataManager {
 			StatusHandler.log(new Status(IStatus.ERROR, ITasksCoreConstants.ID_PLUGIN,
 					"Unexpected error while marking task read", e)); //$NON-NLS-1$
 		}
-		taskList.notifyElementChanged(task);
+		if (changed[0]) {
+			taskList.notifyElementChanged(task);
+		}
 	}
 
 	void putEdits(final ITask itask, final TaskData editsData) throws CoreException {
@@ -468,6 +488,7 @@ public class TaskDataManager implements ITaskDataManager {
 		Assert.isNotNull(task);
 		final String kind = task.getConnectorKind();
 		Assert.isNotNull(editsData);
+		final boolean[] changed = new boolean[1];
 		taskList.run(new ITaskListRunnable() {
 			public void execute(IProgressMonitor monitor) throws CoreException {
 				taskDataStore.putEdits(getFile(task, kind), editsData);
@@ -476,14 +497,18 @@ public class TaskDataManager implements ITaskDataManager {
 				case INCOMING_NEW:
 					// TODO throw exception instead?
 					task.setSynchronizationState(SynchronizationState.CONFLICT);
+					changed[0] = true;
 					break;
 				case SYNCHRONIZED:
 					task.setSynchronizationState(SynchronizationState.OUTGOING);
+					changed[0] = true;
 					break;
 				}
 			}
 		});
-		taskList.notifySynchronizationStateChanged(task);
+		if (changed[0]) {
+			taskList.notifySynchronizationStateChanged(task);
+		}
 	}
 
 	private void fireTaskDataUpdated(final TaskDataManagerEvent event) {
diff --git a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/sync/SynchronizationScheduler.java b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/sync/SynchronizationScheduler.java
new file mode 100644
index 000000000..c2ecf86b1
--- /dev/null
+++ b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/sync/SynchronizationScheduler.java
@@ -0,0 +1,86 @@
+/*******************************************************************************
+ * Copyright (c) 2009 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.internal.tasks.core.sync;
+
+import java.util.HashMap;
+
+import org.eclipse.core.runtime.jobs.IJobChangeEvent;
+import org.eclipse.core.runtime.jobs.Job;
+import org.eclipse.core.runtime.jobs.JobChangeAdapter;
+
+/**
+ * @author Steffen Pingel
+ */
+public class SynchronizationScheduler {
+
+	public static abstract class Synchronizer<T extends Job> {
+
+		private boolean pendingRequest;
+
+		public abstract T createJob();
+
+	}
+
+	public HashMap<Object, Synchronizer<?>> synchronizerByObject;
+
+	public SynchronizationScheduler() {
+		synchronizerByObject = new HashMap<Object, Synchronizer<?>>();
+	}
+
+	public void schedule(final Object object, final Synchronizer<?> synchronizer) {
+		synchronized (synchronizerByObject) {
+			Synchronizer<?> running = synchronizerByObject.get(object);
+			if (running != null) {
+				running.pendingRequest = true;
+				return;
+			} else {
+				synchronizerByObject.put(object, synchronizer);
+			}
+		}
+
+		scheduleJob(object, synchronizer);
+	}
+
+	private void scheduleJob(final Object object, final Synchronizer<?> synchronizer) {
+		final Job job = synchronizer.createJob();
+		final JobChangeAdapter listener = new JobChangeAdapter() {
+			@Override
+			public void done(IJobChangeEvent event) {
+				job.removeJobChangeListener(this);
+				boolean reschedule;
+				synchronized (synchronizerByObject) {
+					reschedule = synchronizer.pendingRequest;
+					if (synchronizer.pendingRequest) {
+						synchronizer.pendingRequest = false;
+					} else {
+						synchronizerByObject.remove(object);
+					}
+				}
+				if (reschedule) {
+					scheduleJob(object, synchronizer);
+				}
+			}
+		};
+		job.addJobChangeListener(listener);
+		job.schedule();
+	}
+
+	public void cancel(Object object) {
+		synchronized (synchronizerByObject) {
+			Synchronizer<?> running = synchronizerByObject.get(object);
+			if (running != null) {
+				running.pendingRequest = false;
+			}
+		}
+	}
+
+}
diff --git a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/sync/SynchronizeTasksJob.java b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/sync/SynchronizeTasksJob.java
index ac8e38de3..c6482d534 100644
--- a/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/sync/SynchronizeTasksJob.java
+++ b/org.eclipse.mylyn.tasks.core/src/org/eclipse/mylyn/internal/tasks/core/sync/SynchronizeTasksJob.java
@@ -254,8 +254,10 @@ public class SynchronizeTasksJob extends SynchronizationJob {
 	}
 
 	private void resetStatus(ITask task) {
-		((AbstractTask) task).setStatus(null);
-		taskList.notifySynchronizationStateChanged(task);
+		if (((AbstractTask) task).getStatus() != null) {
+			((AbstractTask) task).setStatus(null);
+			taskList.notifySynchronizationStateChanged(task);
+		}
 	}
 
 	private void synchronizeTasks(IProgressMonitor monitor, final TaskRepository repository, Set<ITask> tasks)