Add a shutdown callback to taskprocessor listeners.

This helps account for the fact that it is unknown just
how many references may exist for a given taskprocessor
listener, so simply unreffing it from the taskprocessor
shutdown function is not enough to convey the gravity
of the situation.

By putting in a shutdown callback, it now becomes clear
to the listener not to try to do any further operations
on the taskprocessor.

git-svn-id: https://origsvn.digium.com/svn/asterisk/team/mmichelson/threadpool@376381 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/include/asterisk/taskprocessor.h b/include/asterisk/taskprocessor.h
index 5ea1490..895bc17 100644 (file)
--- a/include/asterisk/taskprocessor.h
+++ b/include/asterisk/taskprocessor.h
@@ -86,6 +86,18 @@ struct ast_taskprocessor_listener_callbacks {
         * \param listener The listener
         */
        void (*emptied)(struct ast_taskprocessor_listener *listener);
+       /*!
+        * \brief Indicates the taskprocessor wishes to die.
+        *
+        * All operations on the task processor must to be stopped in
+        * this callback.
+        *
+        * After this callback returns, it is NOT safe to operate on the
+        * listener's reference to the taskprocessor.
+        *
+        * \param listener The listener
+        */
+       void (*shutdown)(struct ast_taskprocessor_listener *listener);
        /*! 
         * \brief Destroy the listener's private data
         *

diff --git a/main/taskprocessor.c b/main/taskprocessor.c
index 00c9485..49e951f 100644 (file)
--- a/main/taskprocessor.c
+++ b/main/taskprocessor.c
@@ -136,7 +136,11 @@ static void listener_destroy(void *obj)
        struct ast_taskprocessor_listener *listener = obj;
 
        listener->callbacks->destroy(listener->private_data);
+}
 
+static void listener_shutdown(struct ast_taskprocessor_listener *listener)
+{
+       listener->callbacks->shutdown(listener);
        ao2_ref(listener->tps, -1);
        listener->tps = NULL;
 }
@@ -184,13 +188,17 @@ static void *default_listener_alloc(struct ast_taskprocessor_listener *listener)
        return pvt;
 }
 
-static void default_listener_destroy(void *obj)
+static void default_listener_shutdown(struct ast_taskprocessor_listener *listener)
 {
-       struct default_taskprocessor_listener_pvt *pvt = obj;
-
+       struct default_taskprocessor_listener_pvt *pvt = listener->private_data;
        default_tps_wake_up(pvt, 1);
        pthread_join(pvt->poll_thread, NULL);
        pvt->poll_thread = AST_PTHREADT_NULL;
+}
+
+static void default_listener_destroy(void *obj)
+{
+       struct default_taskprocessor_listener_pvt *pvt = obj;
        ast_mutex_destroy(&pvt->lock);
        ast_cond_destroy(&pvt->cond);
        ast_free(pvt);
@@ -214,6 +222,7 @@ static const struct ast_taskprocessor_listener_callbacks default_listener_callba
        .alloc = default_listener_alloc,
        .task_pushed = default_task_pushed,
        .emptied = default_emptied,
+       .shutdown = default_listener_shutdown,
        .destroy = default_listener_destroy,
 };
 
@@ -571,6 +580,7 @@ void *ast_taskprocessor_unreference(struct ast_taskprocessor *tps)
        ao2_unlink(tps_singletons, tps);
        listener = tps->listener;
        tps->listener = NULL;
+       listener_shutdown(listener);
        ao2_ref(listener, -1);
        return NULL;
 }
@@ -601,7 +611,7 @@ int ast_taskprocessor_execute(struct ast_taskprocessor *tps)
 {
        struct tps_task *t;
        int size;
-
+       
        if (!(t = tps_taskprocessor_pop(tps))) {
                return 0;
        }

diff --git a/tests/test_taskprocessor.c b/tests/test_taskprocessor.c
index eebf3d0..424449d 100644 (file)
--- a/tests/test_taskprocessor.c
+++ b/tests/test_taskprocessor.c
@@ -103,6 +103,7 @@ struct test_listener_pvt {
        int num_pushed;
        int num_emptied;
        int num_was_empty;
+       int shutdown;
 };
 
 static void *test_alloc(struct ast_taskprocessor_listener *listener)
@@ -128,6 +129,12 @@ static void test_emptied(struct ast_taskprocessor_listener *listener)
        ++pvt->num_emptied;
 }
 
+static void test_shutdown(struct ast_taskprocessor_listener *listener)
+{
+       struct test_listener_pvt *pvt = listener->private_data;
+       pvt->shutdown = 1;
+}
+
 static void test_destroy(void *private_data)
 {
        struct test_listener_pvt *pvt = private_data;
@@ -138,6 +145,7 @@ static const struct ast_taskprocessor_listener_callbacks test_callbacks = {
        .alloc = test_alloc,
        .task_pushed = test_task_pushed,
        .emptied = test_emptied,
+       .shutdown = test_shutdown,
        .destroy = test_destroy,
 };