Merge pull request #227 from p-org/AndExecuteRaceFix

Fixed race condition in AndExecute APIs

Author: pdeligia

Libraries/Core/Library/Machine.cs

@@ -660,13 +660,14 @@ private bool GetNextEvent(out EventInfo nextEventInfo)
         /// is no next event to process or if the machine is halted.
         /// </summary>
         /// <param name="returnEarly">Returns after handling just one event</param>
-        internal async Task RunEventHandler(bool returnEarly = false)
+        internal async Task<bool> RunEventHandler(bool returnEarly = false)
         {
             if (this.IsHalted)
             {
-                return;
+                return true;
             }
 
+            bool completed = false;
             EventInfo nextEventInfo = null;
             while (!this.IsHalted && base.Runtime.IsRunning)
             {
@@ -691,6 +692,7 @@ internal async Task RunEventHandler(bool returnEarly = false)
                         }
                         else
                         {
+                            completed = true;
                             this.IsRunning = false;
                             break;
                         }
@@ -726,9 +728,11 @@ internal async Task RunEventHandler(bool returnEarly = false)
                 // Return after handling the first event?
                 if (returnEarly)
                 {
-                    return;
+                    return false;
                 }
             }
+
+            return completed;
         }
 
         /// <summary>

Libraries/Core/Runtime/StateMachineRuntime.cs

@@ -448,14 +448,16 @@ private void RunMachineEventHandler(Machine machine, Event e, bool isFresh)
         /// <param name="isFresh">Is a new machine</param>
         private async Task RunMachineEventHandlerAsync(Machine machine, Event e, bool isFresh)
         {
+            bool completed;
+
             try
             {
                 if (isFresh)
                 {
                     await machine.GotoStartState(e);
                 }
 
-                await machine.RunEventHandler(true);
+                completed = await machine.RunEventHandler(true);
             }
             catch (AssertionFailureException)
             {
@@ -469,7 +471,10 @@ private async Task RunMachineEventHandlerAsync(Machine machine, Event e, bool is
                 return;
             }
 
-            RunMachineEventHandler(machine, null, false);
+            if (!completed)
+            {
+                RunMachineEventHandler(machine, null, false);
+            }
         }
 
         #endregion