[Mono-bugs] [Bug 78312][Maj] New - Interlocked.Add does not return addition result

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Changed by horst.reiterer at mind-breeze.com.

http://bugzilla.ximian.com/show_bug.cgi?id=78312

--- shadow/78312	2006-05-05 20:28:35.000000000 -0400
+++ shadow/78312.tmp.4476	2006-05-05 20:28:35.000000000 -0400
@@ -0,0 +1,65 @@
+Bug#: 78312
+Product: Mono: Class Libraries
+Version: 1.1
+OS: other
+OS Details: Red Hat Enterprise Linux 4
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Major
+Component: CORLIB
+AssignedTo: mono-bugs at ximian.com                            
+ReportedBy: horst.reiterer at mind-breeze.com               
+QAContact: mono-bugs at ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: Interlocked.Add does not return addition result
+
+The current Interlocked.Add implementation returns the original value, not
+the new value resulting from the atomic addition. The following testcase
+demonstrates that behavior:
+
+using System;
+using System.Threading;
+
+public class Test
+{
+  public static void Main()
+  {
+    int test = 1;
+    int result = Interlocked.Add(ref test, 1);
+
+    if (result != 2) {
+      Console.WriteLine("Incorrect Add result: " + result);
+    }
+  }
+}
+
+According to the SDK documentation, the new value must be returned:
+
+  Return Value
+  The new value stored at location1.
+
+The testcase succeeds when being executed with the CLR.
+
+Steps to reproduce the problem:
+1. mono testcase.cs
+
+Actual Results:
+
+A return value of 1, the original value.
+
+Expected Results:
+
+A return value of 2, the new value.
+
+How often does this happen? 
+
+100 out of 100 times
+
+Additional Information:
+
+Most likely, the incorrect implementation has its roots in the
+specification of Microsoft's InterlockedExchangeAdd which returns the
+original value, not the new value.