Add better listener support.

Add some parameters to listener callbacks.
Add alloc and destroy callbacks for listeners.
Add public function for allocating a listener.



git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@377226 65c4cc65-6c06-0410-ace0-fbb531ad65f3

include/asterisk/threadpool.h

@@ -25,6 +25,15 @@ struct ast_taskprocessor;
 struct ast_threadpool_listener;
 
 struct ast_threadpool_listener_callbacks {
+	/*!
+	 * \brief Allocate the listener's private data
+	 *
+	 * It is not necessary to assign the private data to the listener.
+	 * \param listener The listener the private data will belong to
+	 * \retval NULL Failure to allocate private data
+	 * \retval non-NULL The newly allocated private data
+	 */
+	void *(*alloc)(struct ast_threadpool_listener *listener);
 	/*!
 	 * \brief Indicates that the state of threads in the pool has changed
 	 *
@@ -32,23 +41,31 @@ struct ast_threadpool_listener_callbacks {
 	 * \param active_threads The number of active threads in the pool
 	 * \param idle_threads The number of idle threads in the pool
 	 */
-	void (*state_changed)(struct ast_threadpool_listener *listener,
+	void (*state_changed)(struct ast_threadpool *pool,
+			struct ast_threadpool_listener *listener,
 			int active_threads,
 			int idle_threads);
 	/*!
-	 * \brief Indicates that a task was pushed to the threadpool's taskprocessor
+	 * \brief Indicates that a task was pushed to the threadpool
 	 *
 	 * \param listener The threadpool listener
-	 * \param was_empty Indicates whether the taskprocessor was empty prior to adding the task
+	 * \param was_empty Indicates whether there were any tasks prior to adding the new one.
 	 */
-	void (*tps_task_pushed)(struct ast_threadpool_listener *listener,
+	void (*task_pushed)(struct ast_threadpool *pool,
+			struct ast_threadpool_listener *listener,
 			int was_empty);
 	/*!
 	 * \brief Indicates the threadpoo's taskprocessor has become empty
 	 * 
 	 * \param listener The threadpool's listener
 	 */
-	void (*emptied)(struct ast_threadpool_listener *listener);
+	void (*emptied)(struct ast_threadpool *pool, struct ast_threadpool_listener *listener);
+
+	/*!
+	 * \brief Free the listener's private data
+	 * \param private_data The private data to destroy
+	 */
+	void (*destroy)(void *private_data);
 };
 
 /*!
@@ -60,13 +77,24 @@ struct ast_threadpool_listener_callbacks {
  */
 struct ast_threadpool_listener {
 	/*! Callbacks called by the threadpool */
-	struct ast_threadpool_listener_callbacks *callbacks;
+	const struct ast_threadpool_listener_callbacks *callbacks;
-	/*! Handle to the threadpool */
-	struct ast_threadpool *threadpool;
 	/*! User data for the listener */
 	void *private_data;
 };
 
+/*!
+ * \brief Allocate a threadpool listener
+ *
+ * This function will call back into the alloc callback for the
+ * listener.
+ *
+ * \param callbacks Listener callbacks to assign to the listener
+ * \retval NULL Failed to allocate the listener
+ * \retval non-NULL The newly-created threadpool listener
+ */
+struct ast_threadpool_listener *ast_threadpool_listener_alloc(
+		const struct ast_threadpool_listener_callbacks *callbacks);
+
 /*!
  * \brief Create a new threadpool
  *

main/threadpool.c

@@ -123,7 +123,7 @@ static void threadpool_send_state_changed(struct ast_threadpool *pool)
 	int active_size = ao2_container_count(pool->active_threads);
 	int idle_size = ao2_container_count(pool->idle_threads);
 
-	pool->listener->callbacks->state_changed(pool->listener, active_size, idle_size);
+	pool->listener->callbacks->state_changed(pool, pool->listener, active_size, idle_size);
 }
 
 /*!
@@ -232,11 +232,6 @@ static int threadpool_execute(struct ast_threadpool *pool)
 static void threadpool_destructor(void *obj)
 {
 	struct ast_threadpool *pool = obj;
-	/* XXX Probably should let the listener know we're being destroyed? */
-
-	/* Threads should all be shut down by now, so this should be a painless
-	 * operation
-	 */
 	ao2_cleanup(pool->listener);
 }
 
@@ -342,7 +337,7 @@ static int handle_task_pushed(void *data)
 	struct ast_threadpool *pool = tpd->pool;
 	int was_empty = tpd->was_empty;
 
-	pool->listener->callbacks->tps_task_pushed(pool->listener, was_empty);
+	pool->listener->callbacks->task_pushed(pool, pool->listener, was_empty);
 	ao2_callback(pool->idle_threads, OBJ_UNLINK | OBJ_NOLOCK | OBJ_NODATA | OBJ_MULTIPLE,
 			activate_threads, pool);
 	ao2_ref(tpd, -1);
@@ -382,7 +377,7 @@ static int handle_emptied(void *data)
 {
 	struct ast_threadpool *pool = data;
 
-	pool->listener->callbacks->emptied(pool->listener);
+	pool->listener->callbacks->emptied(pool, pool->listener);
 	return 0;
 }
 
@@ -587,6 +582,29 @@ void ast_threadpool_set_size(struct ast_threadpool *pool, unsigned int size)
 	ast_taskprocessor_push(pool->control_tps, queued_set_size, ssd);
 }
 
+static void listener_destructor(void *obj)
+{
+	struct ast_threadpool_listener *listener = obj;
+
+	listener->callbacks->destroy(listener->private_data);
+}
+
+struct ast_threadpool_listener *ast_threadpool_listener_alloc(
+		const struct ast_threadpool_listener_callbacks *callbacks)
+{
+	struct ast_threadpool_listener *listener = ao2_alloc(sizeof(*listener), listener_destructor);
+	if (!listener) {
+		return NULL;
+	}
+	listener->callbacks = callbacks;
+	listener->private_data = listener->callbacks->alloc(listener);
+	if (!listener->private_data) {
+		ao2_ref(listener, -1);
+		return NULL;
+	}
+	return listener;
+}
+
 struct ast_threadpool *ast_threadpool_create(struct ast_threadpool_listener *listener, int initial_size)
 {
 	struct ast_threadpool *pool;