gst/gstbus.c (gst_bus_remove_signal_watch): New function, removes signal watches previously added via gst_bus_add_sig...

Original commit message from CVS:
2005-09-29  Andy Wingo  <wingo@pobox.com>

* gst/gstbus.c (gst_bus_remove_signal_watch): New function,
removes signal watches previously added via
gst_bus_add_signal_watch.
(gst_bus_add_signal_watch): Don't return the source id, just store
it on the bus if there wasn't an id already.

* gst/gstbus.h (GstBus): Add a couple new fields. API changes for
add_signal_watch and remove_signal_watch.

docs/gst/gstreamer-sections.txt

@@ -92,9 +92,13 @@ gst_bus_peek
 gst_bus_pop
 gst_bus_set_flushing
 gst_bus_set_sync_handler
+gst_bus_sync_signal_handler
 gst_bus_create_watch
 gst_bus_add_watch_full
 gst_bus_add_watch
+gst_bus_async_signal_func
+gst_bus_add_signal_watch
+gst_bus_remove_signal_watch
 gst_bus_poll
 <SUBSECTION Standard>
 GstBusClass
@@ -488,6 +492,7 @@ gst_element_lost_state
 gst_element_message_full
 gst_element_no_more_pads
 gst_element_post_message
+gst_element_provide_clock
 gst_element_provides_clock
 gst_element_query
 gst_element_query_convert
@@ -969,6 +974,8 @@ GST_MESSAGE_TRACE_NAME
 GST_MESSAGE_TYPE
 GST_MESSAGE_UNLOCK
 GST_MESSAGE_WAIT
+gst_message_type_to_quark
+gst_message_type_get_name
 gst_message_copy
 gst_message_get_structure
 gst_message_make_writable

docs/libs/tmpl/gstdataprotocol.sgml

@@ -27,6 +27,9 @@ network connections also need a protocol to do this.
 #GstBuffer, #GstCaps, #GstEvent
 </para>
 
+<!-- ##### SECTION Stability_Level ##### -->
+
+
 <!-- ##### ENUM GstDPHeaderFlag ##### -->
 <para>
 

gst/gstbus.c

@@ -867,22 +867,76 @@ gst_bus_sync_signal_handler (GstBus * bus, GstMessage * message, gpointer data)
 
 /**
  * gst_bus_add_signal_watch:
- * @bus: a #GstBus to create the watch for
+ * @bus: a #GstBus on which you want to recieve the "message" signal
  *
  * Adds a bus signal watch to the default main context with the default priority.
  * After calling this statement, the bus will emit the message signal for each
  * message posted on the bus.
  *
- * The watch can be removed using #g_source_remove().
- *
- * Returns: The event source id.
+ * This function may be called multiple times. To clean up, the caller is
+ * responsible for calling gst_bus_remove_signal_watch() as many times as this
+ * function is called.
  *
  * MT safe.
  */
-guint
+void
 gst_bus_add_signal_watch (GstBus * bus)
 {
-  g_return_val_if_fail (GST_IS_BUS (bus), 0);
+  g_return_if_fail (GST_IS_BUS (bus));
 
-  return gst_bus_add_watch (bus, gst_bus_async_signal_func, NULL);
+  /* I know the callees don't take this lock, so go ahead and abuse it */
+  GST_LOCK (bus);
+
+  if (bus->num_signal_watchers > 0)
+    goto done;
+
+  g_assert (bus->signal_watch_id == 0);
+
+  bus->signal_watch_id =
+      gst_bus_add_watch (bus, gst_bus_async_signal_func, NULL);
+
+done:
+
+  bus->num_signal_watchers++;
+
+  GST_UNLOCK (bus);
+}
+
+/**
+ * gst_bus_remove_signal_watch:
+ * @bus: a #GstBus you previously added a signal watch to
+ *
+ * Removes a signal watch previously added with gst_bus_add_signal_watch().
+ *
+ * MT safe.
+ */
+void
+gst_bus_remove_signal_watch (GstBus * bus)
+{
+  g_return_if_fail (GST_IS_BUS (bus));
+
+  /* I know the callees don't take this lock, so go ahead and abuse it */
+  GST_LOCK (bus);
+
+  if (bus->num_signal_watchers == 0)
+    goto error;
+
+  bus->num_signal_watchers--;
+
+  if (bus->num_signal_watchers > 0)
+    goto done;
+
+  g_source_remove (bus->signal_watch_id);
+  bus->signal_watch_id = 0;
+
+done:
+  GST_UNLOCK (bus);
+  return;
+
+error:
+  {
+    g_critical ("Bus %s has no signal watches attached", GST_OBJECT_NAME (bus));
+    GST_UNLOCK (bus);
+    return;
+  }
 }

gst/gstbus.h

@@ -94,6 +94,9 @@ struct _GstBus
   GstBusSyncHandler sync_handler;
   gpointer 	    sync_handler_data;
 
+  guint             signal_watch_id;
+  guint             num_signal_watchers;
+
   /*< private > */
   gpointer _gst_reserved[GST_PADDING];
 };
@@ -144,8 +147,10 @@ gboolean		gst_bus_async_signal_func	(GstBus *bus, GstMessage *message,
 							 gpointer data);
 GstBusSyncReply		gst_bus_sync_signal_handler	(GstBus *bus, GstMessage *message,
 							 gpointer data);
-/* add watch that dispatches signals */
-guint 			gst_bus_add_signal_watch 	(GstBus * bus);
+
+/* convenience api to add/remove a gsource that emits the async signals */
+void 			gst_bus_add_signal_watch 	(GstBus * bus);
+void 			gst_bus_remove_signal_watch 	(GstBus * bus);
 
 G_END_DECLS