1 files changed, 138 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/core-spi/src/main/java/org/apache/tuscany/sca/context/ThreadMessageContext.java b/sca-java-2.x/tags/2.0.1-RC1/modules/core-spi/src/main/java/org/apache/tuscany/sca/context/ThreadMessageContext.java
new file mode 100644
index 0000000000..ea1b8b6d30
--- /dev/null
+++ b/sca-java-2.x/tags/2.0.1-RC1/modules/core-spi/src/main/java/org/apache/tuscany/sca/context/ThreadMessageContext.java
@@ -0,0 +1,138 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+package org.apache.tuscany.sca.context;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.tuscany.sca.assembly.Endpoint;
+import org.apache.tuscany.sca.assembly.EndpointReference;
+import org.apache.tuscany.sca.interfacedef.Operation;
+import org.apache.tuscany.sca.invocation.Message;
+
+/**
+ * Class for tunnelling a WorkContext through the invocation of a user class.
+ *
+ * @version $Rev$ $Date$
+ */
+public final class ThreadMessageContext {
+    
+        // TUSCANY-3770: Used as a marker for detecting when thread context information can be removed
+        private static final Message msg = new Message() {
+        private Map<String, Object> headers = new HashMap<String, Object>();
+        public void setTo(Endpoint to) {}
+        public void setOperation(Operation op) {}
+        public void setMessageID(Object messageId) {}
+        public void setFrom(EndpointReference from) {}
+        public <T> void setFaultBody(T fault) {}
+        public <T> void setBody(T body) {}
+        public <T> void setBindingContext(T bindingContext) {}
+        public boolean isFault() {
+            return false;
+        }
+        public Endpoint getTo() {
+            return null;
+        }
+        public Operation getOperation() {
+            return null;
+        }
+        public Object getMessageID() {
+            return null;
+        }
+        public Map<String, Object> getHeaders() {
+            return headers;
+        }
+        public EndpointReference getFrom() {
+            return null;
+        }
+        public <T> T getBody() {
+            return null;
+        }
+        public <T> T getBindingContext() {
+            return null;
+        }
+    };
+
+    private static final ThreadLocal<Message> CONTEXT = new ThreadLocal<Message>(){
+        @Override
+        protected synchronized Message initialValue() {
+            return msg;
+        }
+    };
+    
+    private static final ThreadLocal<Message> PREVIOUS_CONTEXT = new ThreadLocal<Message>();
+
+    private ThreadMessageContext() {
+    }
+
+    /**
+     * Set the WorkContext for the current thread.
+     * The current work context is returned and must be restored after the invocation is complete.
+     * Typical usage would be:
+     * <pre>
+     *   WorkContext old = PojoWorkContextTunnel.setThreadWorkContext(newContext);
+     *   try {
+     *      ... invoke user code ...
+     *   } finally {
+     *     PojoWorkContextTunnel.setThreadWorkContext(old);
+     *   }
+     * </pre>
+     * @param context
+     * @return the current work context for the thread; this must be restored after the invocation is made
+     */
+    public static Message setMessageContext(Message context) {
+        Message old = CONTEXT.get();
+        CONTEXT.set(context);
+        PREVIOUS_CONTEXT.set(old);
+        
+        // TUSCANY-3770: Remove thread context information when the request invocation has completed
+        if (context == msg) {
+            removeMessageContext();
+            removePreviousMessageContext();
+        }
+        return old;
+    }
+
+    /**
+     * Returns the WorkContext for the current thread.
+     *
+     * @return the WorkContext for the current thread
+     */
+    public static Message getMessageContext() {
+        return CONTEXT.get();
+    }
+    
+    public static Message getPreviousMessageContext() {
+        return PREVIOUS_CONTEXT.get();
+    }
+
+    /**
+     * Removes any state from the current thread to ensure that
+     * any associated classloaders can be GCd
+     */
+    // TUSCANY-3770: The thread context information is removed implicitly above    
+    public static void removeMessageContext() {
+        CONTEXT.remove();
+    }
+
+    //for performance concerns - set to null rather than call remove
+    public static void removePreviousMessageContext() {
+        PREVIOUS_CONTEXT.set(null);
+    }
+}