[Mono-bugs] [Bug 55909][Wis] New - Deadlock in ReaderWriterLock.UpgradeToWriterLock()

[bugzilla-daemon@bugzilla.ximian.com]

Please do not reply to this email- if you want to comment on the bug, go to the
URL shown below and enter your comments there.

Changed by mono-bug@jerryweb.info.

http://bugzilla.ximian.com/show_bug.cgi?id=55909

--- shadow/55909	2004-03-22 13:04:25.000000000 -0500
+++ shadow/55909.tmp.3766	2004-03-22 13:04:25.000000000 -0500
@@ -0,0 +1,95 @@
+Bug#: 55909
+Product: Mono: Class Libraries
+Version: unspecified
+OS: GNU/Linux [Other]
+OS Details: Gentoo
+Status: NEW   
+Resolution: 
+Severity: 
+Priority: Wishlist
+Component: CORLIB
+AssignedTo: mono-bugs@ximian.com                            
+ReportedBy: mono-bug@jerryweb.info               
+QAContact: mono-bugs@ximian.com
+TargetMilestone: ---
+URL: 
+Cc: 
+Summary: Deadlock in ReaderWriterLock.UpgradeToWriterLock()
+
+Description of Problem:
+Deadlock in ReaderWriterLock.UpgradeToWriterLock()
+
+Steps to reproduce the problem:
+
+Run this code:
+===================================================================
+using System;
+using System.Threading;
+
+namespace Example {
+   class Class1 {
+      static ReaderWriterLock _rwl = new ReaderWriterLock();
+      const int _timeout = Timeout.Infinite;
+
+      [STAThread]
+      static void Main(string[] args) {
+         Thread th = new Thread(new ThreadStart(Thread2));
+         th.Start();
+         Thread.Sleep(1000);
+         Console.WriteLine("1 - AcquireReaderLock, before");
+         _rwl.AcquireReaderLock(Timeout.Infinite);
+         Console.WriteLine("1 - AcquireReaderLock, after");
+         try {
+            Console.WriteLine("1 - UpgradeToWriterLock, before");
+            LockCookie lc = _rwl.UpgradeToWriterLock(_timeout);
+            Console.WriteLine("1 - UpgradeToWriterLock, after");
+            Thread.Sleep(500);
+            Console.WriteLine("1 - Release, before");
+         }
+         finally { _rwl.ReleaseReaderLock(); }
+         Console.WriteLine("1 - End");
+      }
+
+      static void Thread2() {
+         Console.WriteLine("2 - AcquireReaderLock, before");
+         _rwl.AcquireReaderLock(Timeout.Infinite);
+         Console.WriteLine("2 - AcquireReaderLock, after");
+         try {
+            Thread.Sleep(3000);
+            Console.WriteLine("2 - UpgradeToWriterLock, before");
+            LockCookie lc = _rwl.UpgradeToWriterLock(_timeout);
+            Console.WriteLine("2 - UpgradeToWriterLock, after");
+            Thread.Sleep(2000);
+            Console.WriteLine("2 - Release, before");
+         }
+         finally { _rwl.ReleaseReaderLock(); }
+         Console.WriteLine("2 - End");
+      }
+   }
+}
+===================================================================
+
+Actual Results:
+
+MS.NET 1.0:
+2 - AcquireReaderLock, before
+2 - AcquireReaderLock, after
+1 - AcquireReaderLock, before
+1 - AcquireReaderLock, after
+1 - UpgradeToWriterLock, before
+2 - UpgradeToWriterLock, before
+1 - UpgradeToWriterLock, after
+1 - Release, before
+1 - End
+2 - UpgradeToWriterLock, after
+2 - Release, before
+2 - End
+
+Mono 0.31, Gentoo Linux:
+2 - AcquireReaderLock, before
+2 - AcquireReaderLock, after
+1 - AcquireReaderLock, before
+1 - AcquireReaderLock, after
+1 - UpgradeToWriterLock, before
+2 - UpgradeToWriterLock, before
+...???