Fix for lock release in SynchronizationAttribute

* Making sure ownerThread is not nulled unless lockCount is zero.
* Fixed so Locked property checks lockCount when determining if locked
   instead of _locked field which was never set.
* Added test for setting Locked property.
* Added test capturing the original issue.

3 files changed, 40 insertions, 13 deletions

diff --git a/mcs/class/corlib/System.Runtime.Remoting.Contexts/SynchronizationAttribute.cs b/mcs/class/corlib/System.Runtime.Remoting.Contexts/SynchronizationAttribute.cs
index 7ef860da45f..49628abb344 100644
--- a/mcs/class/corlib/System.Runtime.Remoting.Contexts/SynchronizationAttribute.cs
+++ b/mcs/class/corlib/System.Runtime.Remoting.Contexts/SynchronizationAttribute.cs
@@ -47,8 +47,6 @@ namespace System.Runtime.Remoting.Contexts
 		int _flavor;
 
 		[NonSerialized]
-		bool _locked;
-		[NonSerialized]
 		int _lockCount;
 		
 		[NonSerialized]
@@ -90,32 +88,26 @@ namespace System.Runtime.Remoting.Contexts
 		{
 			get 
 			{ 
-				return _locked; 
+				return _lockCount > 0; 
 			}
 			
 			set 
 			{
 				if (value)
 				{
-					_mutex.WaitOne ();
+					AcquireLock ();
 					lock (this)
 					{
-						_lockCount++;
 						if (_lockCount > 1)
 							ReleaseLock (); // Thread already had the lock
-							
-						_ownerThread = Thread.CurrentThread;
 					}
 				}
 				else
 				{
 					lock (this)
 					{
-						while (_lockCount > 0 && _ownerThread == Thread.CurrentThread)
-						{
-							_lockCount--;
-							_mutex.ReleaseMutex ();
-							_ownerThread = null;
+						while (_lockCount > 0 && _ownerThread == Thread.CurrentThread) {
+							ReleaseLock ();
 						}
 					}
 				}
@@ -140,7 +132,9 @@ namespace System.Runtime.Remoting.Contexts
 				if (_lockCount > 0 && _ownerThread == Thread.CurrentThread) {
 					_lockCount--;
 					_mutex.ReleaseMutex ();
-					_ownerThread = null;
+					if (_lockCount == 0) {
+						_ownerThread = null;
+					}
 				}
 			}
 		}
diff --git a/mcs/class/corlib/Test/System.Runtime.Remoting.Contexts/SynchronizationAttributeTest.cs b/mcs/class/corlib/Test/System.Runtime.Remoting.Contexts/SynchronizationAttributeTest.cs
index ba69ed0503b..a217969aefd 100644
--- a/mcs/class/corlib/Test/System.Runtime.Remoting.Contexts/SynchronizationAttributeTest.cs
+++ b/mcs/class/corlib/Test/System.Runtime.Remoting.Contexts/SynchronizationAttributeTest.cs
@@ -72,6 +72,23 @@ namespace MonoTests.System.Runtime.Remoting.Contexts {
 		}
 
 		[Test]
+	    public void SetLocked()
+		{
+			SynchronizationAttribute sa = new SynchronizationAttribute(SynchronizationAttribute.REQUIRES_NEW);
+			sa.Locked = true;
+			Assert.IsTrue(sa.Locked, "Locked");
+			sa.Locked = false;
+			Assert.IsFalse(sa.Locked, "Locked");
+
+			sa.Locked = true;
+			Assert.IsTrue(sa.Locked, "Locked");
+			sa.Locked = true;
+			Assert.IsTrue(sa.Locked, "Locked");
+			sa.Locked = false;
+			Assert.IsFalse(sa.Locked, "Locked");
+		}
+
+		[Test]
 		public void SerializationRoundtrip ()
 		{
 			SynchronizationAttribute sa = new SynchronizationAttribute (SynchronizationAttribute.NOT_SUPPORTED, true);
diff --git a/mcs/class/corlib/Test/System.Runtime.Remoting/SynchronizationAttributeTest.cs b/mcs/class/corlib/Test/System.Runtime.Remoting/SynchronizationAttributeTest.cs
index 7596f3fd8bd..4005d1ad6c5 100644
--- a/mcs/class/corlib/Test/System.Runtime.Remoting/SynchronizationAttributeTest.cs
+++ b/mcs/class/corlib/Test/System.Runtime.Remoting/SynchronizationAttributeTest.cs
@@ -220,6 +220,7 @@ namespace MonoTests.System.Runtime.Remoting
 		public void TestLocked1 ()
 		{
 			sincob.Lock (false);
+
 			Thread tr = new Thread (new ThreadStart (FirstSyncThread));
 			tr.Start ();
 			Thread.Sleep (200);
@@ -331,6 +332,21 @@ namespace MonoTests.System.Runtime.Remoting
 			Assert.IsTrue (!otResult, "Concurrency detected in CallbackThread");
 		}
 
+		[Test]
+		public void TestSynchronizationReleasedOnMultipleAcquire ()
+		{
+
+			otResult = notreentrant.TestCallback ();
+		    
+			Thread tr = new Thread (new ThreadStart (CallbackThread));
+			tr.Start();
+			
+			bool terminated = tr.Join(2000);
+			Assert.IsTrue(terminated, "Thread didn't get lock of context bound object.");
+			
+			Assert.IsTrue (!otResult, "Concurrency detected in CallbackThread");
+		}
+
 		void CallbackThread ()
 		{
 			otResult = notreentrant.TestCallback ();