Internal worker is kept while there is an ongoing operation

	When there is an ongoing operation we can't dispose the internal
	worker because it might be used by the IO threadpool.

	Fixes Novell bug #691076 and Xamarin bug #766.

diff --git a/mcs/class/System/System.Net.Sockets/SocketAsyncEventArgs.cs b/mcs/class/System/System.Net.Sockets/SocketAsyncEventArgs.cs
index 774eddc17e5efb94c8aeabc96119047f20ac1f7a..bd9f574fefff3c950c10f28fcfae9d039a3c2302 100644 (file)
--- a/mcs/class/System/System.Net.Sockets/SocketAsyncEventArgs.cs
+++ b/mcs/class/System/System.Net.Sockets/SocketAsyncEventArgs.cs
@@ -2,9 +2,10 @@
 //
 // Authors:
 //     Marek Habersack (mhabersack@novell.com)
-//     Gonzalo Paniagua Javier (gonzalo@novell.com)
+//     Gonzalo Paniagua Javier (gonzalo@xamarin.com)
 //
 // Copyright (c) 2008,2010 Novell, Inc. (http://www.novell.com)
+// Copyright (c) 2011 Xamarin, Inc. (http://xamarin.com)
 //
 
 //
@@ -37,6 +38,8 @@ namespace System.Net.Sockets
 {
        public class SocketAsyncEventArgs : EventArgs, IDisposable
        {
+               bool disposed;
+               int in_progress;
                internal Socket.Worker Worker;
                EndPoint remote_ep;
 #if MOONLIGHT || NET_4_0
@@ -147,7 +150,11 @@ namespace System.Net.Sockets
 
                void Dispose (bool disposing)
                {
+                       disposed = true;
+
                        if (disposing) {
+                               if (disposed || Interlocked.CompareExchange (ref in_progress, 0, 0) != 0)
+                                       return;
                                if (Worker != null) {
                                        Worker.Dispose ();
                                        Worker = null;
@@ -171,6 +178,10 @@ namespace System.Net.Sockets
 
                internal void SetLastOperation (SocketAsyncOperation op)
                {
+                       if (disposed)
+                               throw new ObjectDisposedException ("System.Net.Sockets.SocketAsyncEventArgs");
+                       if (Interlocked.Exchange (ref in_progress, 1) != 0)
+                               throw new InvalidOperationException ("Operation already in progress");
                        LastOperation = op;
                }
 
@@ -219,6 +230,8 @@ namespace System.Net.Sockets
                static void DispatcherCB (IAsyncResult ares)
                {
                        SocketAsyncEventArgs args = (SocketAsyncEventArgs) ares.AsyncState;
+                       if (Interlocked.Exchange (ref args.in_progress, 0) != 1)
+                               throw new InvalidOperationException ("No operation in progress");
                        SocketAsyncOperation op = args.LastOperation;
                        // Notes;
                        //      -SocketOperation.AcceptReceive not used in SocketAsyncEventArgs