Added interface PubSubSupport

src/main/java/net/engio/mbassy/PubSubSupport.java

@@ -0,0 +1,41 @@
+package net.engio.mbassy;
+
+/**
+ * This interface defines the very basic message publication semantics according to the publish subscribe pattern.
+ *
+ * Listeners can be subscribed and unsubscribed using the corresponding methods. When a listener is subscribed
+ *
+ *
+ */
+public interface PubSubSupport<T> {
+
+    /**
+     * Subscribe all handler of the given listener. Any listener may only be subscribed once
+     * -> subsequent subscriptions of an already subscribed listener will be silently ignored)
+     *
+     * @param listener
+     */
+    void subscribe(Object listener);
+
+    /**
+     * Immediately remove all registered message handlers (if any) of the given listener. When this call returns all handlers
+     * have effectively been removed and will not receive any message publications (including asynchronously scheduled
+     * publications that have been published when the message listener was still subscribed).
+     * <p/>
+     * A call to this method passing any object that is not subscribed will not have any effect and is silently ignored.
+     *
+     * @param listener
+     * @return true, if the listener was found and successfully removed
+     *         false otherwise
+     */
+    boolean unsubscribe(Object listener);
+
+
+    /**
+     * Synchronously publish a message to all registered listeners (this includes listeners defined for super types)
+     * The call blocks until every messageHandler has processed the message.
+     *
+     * @param message
+     */
+    void publish(T message);
+}