Remove "optimization" that could cause a deadlock

diff --git a/mcs/class/System.Threading.Tasks.Dataflow/System.Threading.Tasks.Dataflow/JoinBlock`3.cs b/mcs/class/System.Threading.Tasks.Dataflow/System.Threading.Tasks.Dataflow/JoinBlock`3.cs
index ad72232e18ba006ea87706351e2d56c11f1b588f..4a7c85bb2637bcf3fb71172398b443898c0bd028 100644 (file)
--- a/mcs/class/System.Threading.Tasks.Dataflow/System.Threading.Tasks.Dataflow/JoinBlock`3.cs
+++ b/mcs/class/System.Threading.Tasks.Dataflow/System.Threading.Tasks.Dataflow/JoinBlock`3.cs
@@ -59,14 +59,9 @@ namespace System.Threading.Tasks.Dataflow
 
                        this.dataflowBlockOptions = dataflowBlockOptions;
 
-                       Func<bool> checker1 = () => target2.Buffer.Count == 0 || target3.Buffer.Count == 0;
-                       Func<bool> checker2 = () => target1.Buffer.Count == 0 || target3.Buffer.Count == 0;
-                       Func<bool> checker3 = () => target1.Buffer.Count == 0 || target2.Buffer.Count == 0;
-
-                       Func<bool> joinTargetCompleteTester = () => outgoing.IsCompleted;
-                       target1 = new JoinTarget<T1> (this, () => SignalArrivalTargetImpl (checker1), compHelper, joinTargetCompleteTester);
-                       target2 = new JoinTarget<T2> (this, () => SignalArrivalTargetImpl (checker2), compHelper, joinTargetCompleteTester);
-                       target3 = new JoinTarget<T3> (this, () => SignalArrivalTargetImpl (checker3), compHelper, joinTargetCompleteTester);
+                       target1 = new JoinTarget<T1> (this, SignalArrivalTargetImpl, compHelper, () => outgoing.IsCompleted);
+                       target2 = new JoinTarget<T2> (this, SignalArrivalTargetImpl, compHelper, () => outgoing.IsCompleted);
+                       target3 = new JoinTarget<T3> (this, SignalArrivalTargetImpl, compHelper, () => outgoing.IsCompleted);
                        outgoing =
                                new MessageOutgoingQueue<Tuple<T1, T2, T3>> (compHelper,
                                                                             () => target1.Buffer.IsCompleted || target2.Buffer.IsCompleted || target3.Buffer.IsCompleted);
@@ -121,7 +116,7 @@ namespace System.Threading.Tasks.Dataflow
                }
 
                // TODO : see if we can find a lockless implementation
-               void SignalArrivalTargetImpl (Func<bool> check)
+               void SignalArrivalTargetImpl ()
                {
                        bool taken = false;
                        T1 value1;
@@ -130,7 +125,8 @@ namespace System.Threading.Tasks.Dataflow
 
                        try {
                                targetLock.Enter (ref taken);
-                               if (check ())
+
+                               if (target1.Buffer.Count == 0 || target2.Buffer.Count == 0 || target3.Buffer.Count == 0)
                                        return;
 
                                value1 = target1.Buffer.Take ();