proper thread cancellation when using the charon->interfaces

src/charon/bus/bus.h

@@ -265,6 +265,14 @@ struct bus_t {
 	 */
 	void (*add_listener) (bus_t *this, bus_listener_t *listener);
 	
+	/**
+	 * @brief Unregister a listener from the bus.
+	 *
+	 * @param this		bus
+	 * @param listener	listener to unregister.
+	 */
+	void (*remove_listener) (bus_t *this, bus_listener_t *listener);
+	
 	/**
 	 * @brief Listen actively on the bus.
 	 *
@@ -275,6 +283,9 @@ struct bus_t {
 	 * it processes a signal, registration is required. This is done through
 	 * the set_listen_state() method, see below.
 	 *
+	 * The listen() function is (has) a thread cancellation point, so might
+	 * want to register cleanup handlers.
+	 *
 	 * @param this		bus
 	 * @param level		verbosity level of the signal
 	 * @param thread	receives thread number emitted the signal