X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fclass%2Fcorlib%2FSystem.Runtime.Serialization%2FSerializationCallbacks.cs;h=49fbb1270a182e59e237c5fd1275166a0575d776;hb=0fb43d6e9f83cff60cc8cd9903dc0a829b101ee6;hp=7df6ec80b41258fe6e021c695f22faf254d4a28d;hpb=af90548a08ef5effc93b083b7eec44daa178b141;p=mono.git

diff --git a/mcs/class/corlib/System.Runtime.Serialization/SerializationCallbacks.cs b/mcs/class/corlib/System.Runtime.Serialization/SerializationCallbacks.cs
index 7df6ec80b41..49fbb1270a1 100644
--- a/mcs/class/corlib/System.Runtime.Serialization/SerializationCallbacks.cs
+++ b/mcs/class/corlib/System.Runtime.Serialization/SerializationCallbacks.cs
@@ -26,8 +26,6 @@
 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 //
 
-#if NET_2_0
-
 using System;
 using System.Collections;
 using System.Reflection;
@@ -137,20 +135,26 @@ namespace System.Runtime.Serialization {
 		}
 
 		static Hashtable cache = new Hashtable ();
-
+		static object cache_lock = new object ();
+		
 		public static SerializationCallbacks GetSerializationCallbacks (Type t)
 		{
-			lock (cache.SyncRoot) {
+			SerializationCallbacks sc = (SerializationCallbacks) cache [t];
+			if (sc != null)
+				return sc;
 
-				SerializationCallbacks sc = (SerializationCallbacks)  cache [t];
+			// Slow path, new entry, we need to copy
+			lock (cache_lock){
+				sc = (SerializationCallbacks)  cache [t];
 				if (sc == null) {
+					Hashtable copy = (Hashtable) cache.Clone ();
+				
 					sc = new SerializationCallbacks (t);
-					cache [t] = sc;
+					copy [t] = sc;
+					cache = copy;
 				}
 				return sc;
 			}
 		}
 	}
 }
-
-#endif