Don't call Abort() if operation is alredy in aborting state

Author: nerzhulart

Mono.Debugging/Mono.Debugging.Evaluation/AsyncOperationBase.cs

@@ -32,6 +32,7 @@ public interface IAsyncOperationBase
 	{
 		Task RawTask { get; }
 		string Description { get; }
+		bool AbortCalled { get; }
 		void Abort ();
 	}
 
@@ -59,6 +60,8 @@ public Task RawTask
 		/// </summary>
 		protected CancellationToken Token { get { return tokenSource.Token; } }
 
+		public bool AbortCalled { get { return Token.IsCancellationRequested; } }
+
 		public void Abort ()
 		{
 			try {

Mono.Debugging/Mono.Debugging.Evaluation/AsyncOperationManager.cs

@@ -76,9 +76,12 @@ public OperationResult<TValue> Invoke<TValue> (AsyncOperationBase<TValue> mc, in
 					return task.Result;
 				}
 				DebuggerLoggingService.LogMessage (string.Format ("Invoke {0} timed out after {1} ms. Cancelling.", description, timeout));
-				mc.Abort ();
+				var abortCalled = mc.AbortCalled;
+				// if abort was already called (in AbortAll/Dispose) don't call it again, just wait
+				if (!abortCalled)
+					mc.Abort ();
 				try {
-					WaitAfterCancel (mc);
+					WaitAfterCancel (mc, abortCalled);
 				}
 				catch (Exception e) {
 					if (IsOperationCancelledException (e)) {
@@ -119,7 +122,7 @@ void ChangeBusyState (bool busy, string description)
 			}
 		}
 
-		void WaitAfterCancel (IAsyncOperationBase op)
+		void WaitAfterCancel (IAsyncOperationBase op, bool onlyWait)
 		{
 			var desc = op.Description;
 			DebuggerLoggingService.LogMessage (string.Format ("Waiting for cancel of invoke {0}", desc));
@@ -131,7 +134,9 @@ void WaitAfterCancel (IAsyncOperationBase op)
 							if (disposed)
 								break;
 						}
-						op.Abort ();
+						if (!onlyWait) {
+							op.Abort ();
+						}
 						if (op.RawTask.Wait (ShortCancelTimeout))
 							break;
 					}
@@ -160,9 +165,13 @@ void CancelOperations (List<IAsyncOperationBase> operations, bool wait)
 			foreach (var operation in operations) {
 				var taskDescription = operation.Description;
 				try {
-					operation.Abort ();
+					var abortCalled = operation.AbortCalled;
+					// if abort was already called (in AbortAll/Dispose) don't call it again, just wait
+					if (!abortCalled) {
+						operation.Abort ();
+					}
 					if (wait) {
-						WaitAfterCancel (operation);
+						WaitAfterCancel (operation, abortCalled);
 					}
 				}
 				catch (Exception e) {