mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-09-08 21:28:45 +00:00
class_init is too late for calling g_thread_init() as g_thread_init() needs to be called before any GObject function.
1312 lines
36 KiB
C
1312 lines
36 KiB
C
/* GStreamer
|
|
* Copyright (C) 2004 Wim Taymans <wim@fluendo.com>
|
|
*
|
|
* gstbus.c: GstBus subsystem
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Library General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 of the License, or (at your option) any later version.
|
|
*
|
|
* This library is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* Library General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Library General Public
|
|
* License along with this library; if not, write to the
|
|
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
* Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
/**
|
|
* SECTION:gstbus
|
|
* @short_description: Asynchronous message bus subsystem
|
|
* @see_also: #GstMessage, #GstElement
|
|
*
|
|
* The #GstBus is an object responsible for delivering #GstMessages in
|
|
* a first-in first-out way from the streaming threads to the application.
|
|
*
|
|
* Since the application typically only wants to deal with delivery of these
|
|
* messages from one thread, the GstBus will marshall the messages between
|
|
* different threads. This is important since the actual streaming of media
|
|
* is done in another thread than the application.
|
|
*
|
|
* The GstBus provides support for #GSource based notifications. This makes it
|
|
* possible to handle the delivery in the glib mainloop.
|
|
*
|
|
* The #GSource callback function gst_bus_async_signal_func() can be used to
|
|
* convert all bus messages into signal emissions.
|
|
*
|
|
* A message is posted on the bus with the gst_bus_post() method. With the
|
|
* gst_bus_peek() and gst_bus_pop() methods one can look at or retrieve a
|
|
* previously posted message.
|
|
*
|
|
* The bus can be polled with the gst_bus_poll() method. This methods blocks
|
|
* up to the specified timeout value until one of the specified messages types
|
|
* is posted on the bus. The application can then _pop() the messages from the
|
|
* bus to handle them.
|
|
* Alternatively the application can register an asynchronous bus function
|
|
* using gst_bus_add_watch_full() or gst_bus_add_watch(). This function will
|
|
* install a #GSource in the default glib main loop and will deliver messages
|
|
* a short while after they have been posted. Note that the main loop should
|
|
* be running for the asynchronous callbacks.
|
|
*
|
|
* It is also possible to get messages from the bus without any thread
|
|
* marshalling with the gst_bus_set_sync_handler() method. This makes it
|
|
* possible to react to a message in the same thread that posted the
|
|
* message on the bus. This should only be used if the application is able
|
|
* to deal with messages from different threads.
|
|
*
|
|
* Every #GstPipeline has one bus.
|
|
*
|
|
* Note that a #GstPipeline will set its bus into flushing state when changing
|
|
* from READY to NULL state.
|
|
*
|
|
* Last reviewed on 2006-03-12 (0.10.5)
|
|
*/
|
|
|
|
#include "gst_private.h"
|
|
#include <errno.h>
|
|
#ifdef HAVE_UNISTD_H
|
|
# include <unistd.h>
|
|
#endif
|
|
#include <sys/types.h>
|
|
|
|
#include "gstinfo.h"
|
|
|
|
#include "gstbus.h"
|
|
|
|
#define GST_CAT_DEFAULT GST_CAT_BUS
|
|
/* bus signals */
|
|
enum
|
|
{
|
|
SYNC_MESSAGE,
|
|
ASYNC_MESSAGE,
|
|
/* add more above */
|
|
LAST_SIGNAL
|
|
};
|
|
|
|
static void gst_bus_class_init (GstBusClass * klass);
|
|
static void gst_bus_init (GstBus * bus);
|
|
static void gst_bus_dispose (GObject * object);
|
|
|
|
static void gst_bus_set_main_context (GstBus * bus, GMainContext * ctx);
|
|
|
|
static GstObjectClass *parent_class = NULL;
|
|
static guint gst_bus_signals[LAST_SIGNAL] = { 0 };
|
|
|
|
struct _GstBusPrivate
|
|
{
|
|
guint num_sync_message_emitters;
|
|
GCond *queue_cond;
|
|
GSource *watch_id;
|
|
GMainContext *main_context;
|
|
};
|
|
|
|
G_DEFINE_TYPE (GstBus, gst_bus, GST_TYPE_OBJECT);
|
|
|
|
/* fixme: do something about this */
|
|
static void
|
|
marshal_VOID__MINIOBJECT (GClosure * closure, GValue * return_value,
|
|
guint n_param_values, const GValue * param_values, gpointer invocation_hint,
|
|
gpointer marshal_data)
|
|
{
|
|
typedef void (*marshalfunc_VOID__MINIOBJECT) (gpointer obj, gpointer arg1,
|
|
gpointer data2);
|
|
register marshalfunc_VOID__MINIOBJECT callback;
|
|
register GCClosure *cc = (GCClosure *) closure;
|
|
register gpointer data1, data2;
|
|
|
|
g_return_if_fail (n_param_values == 2);
|
|
|
|
if (G_CCLOSURE_SWAP_DATA (closure)) {
|
|
data1 = closure->data;
|
|
data2 = g_value_peek_pointer (param_values + 0);
|
|
} else {
|
|
data1 = g_value_peek_pointer (param_values + 0);
|
|
data2 = closure->data;
|
|
}
|
|
callback =
|
|
(marshalfunc_VOID__MINIOBJECT) (marshal_data ? marshal_data :
|
|
cc->callback);
|
|
|
|
callback (data1, gst_value_get_mini_object (param_values + 1), data2);
|
|
}
|
|
|
|
static void
|
|
gst_bus_class_init (GstBusClass * klass)
|
|
{
|
|
GObjectClass *gobject_class = (GObjectClass *) klass;
|
|
|
|
parent_class = g_type_class_peek_parent (klass);
|
|
|
|
gobject_class->dispose = GST_DEBUG_FUNCPTR (gst_bus_dispose);
|
|
|
|
/**
|
|
* GstBus::sync-message:
|
|
* @bus: the object which received the signal
|
|
* @message: the message that has been posted synchronously
|
|
*
|
|
* A message has been posted on the bus. This signal is emitted from the
|
|
* thread that posted the message so one has to be careful with locking.
|
|
*
|
|
* This signal will not be emitted by default, you have to set up
|
|
* gst_bus_sync_signal_handler() as a sync handler if you want this
|
|
* signal to be emitted when a message is posted on the bus, like this:
|
|
* <programlisting>
|
|
* gst_bus_set_sync_handler (bus, gst_bus_sync_signal_handler, yourdata);
|
|
* </programlisting>
|
|
*/
|
|
gst_bus_signals[SYNC_MESSAGE] =
|
|
g_signal_new ("sync-message", G_TYPE_FROM_CLASS (klass),
|
|
G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
|
|
G_STRUCT_OFFSET (GstBusClass, sync_message), NULL, NULL,
|
|
marshal_VOID__MINIOBJECT, G_TYPE_NONE, 1, GST_TYPE_MESSAGE);
|
|
|
|
/**
|
|
* GstBus::message:
|
|
* @bus: the object which received the signal
|
|
* @message: the message that has been posted asynchronously
|
|
*
|
|
* A message has been posted on the bus. This signal is emitted from a
|
|
* GSource added to the mainloop. this signal will only be emitted when
|
|
* there is a mainloop running.
|
|
*/
|
|
gst_bus_signals[ASYNC_MESSAGE] =
|
|
g_signal_new ("message", G_TYPE_FROM_CLASS (klass),
|
|
G_SIGNAL_RUN_LAST | G_SIGNAL_DETAILED,
|
|
G_STRUCT_OFFSET (GstBusClass, message), NULL, NULL,
|
|
marshal_VOID__MINIOBJECT, G_TYPE_NONE, 1, GST_TYPE_MESSAGE);
|
|
|
|
g_type_class_add_private (klass, sizeof (GstBusPrivate));
|
|
}
|
|
|
|
static void
|
|
gst_bus_init (GstBus * bus)
|
|
{
|
|
bus->queue = g_queue_new ();
|
|
bus->queue_lock = g_mutex_new ();
|
|
|
|
bus->priv = G_TYPE_INSTANCE_GET_PRIVATE (bus, GST_TYPE_BUS, GstBusPrivate);
|
|
bus->priv->queue_cond = g_cond_new ();
|
|
|
|
GST_DEBUG_OBJECT (bus, "created");
|
|
}
|
|
|
|
static void
|
|
gst_bus_dispose (GObject * object)
|
|
{
|
|
GstBus *bus = GST_BUS (object);
|
|
|
|
if (bus->queue) {
|
|
GstMessage *message;
|
|
|
|
g_mutex_lock (bus->queue_lock);
|
|
do {
|
|
message = g_queue_pop_head (bus->queue);
|
|
if (message)
|
|
gst_message_unref (message);
|
|
} while (message != NULL);
|
|
g_queue_free (bus->queue);
|
|
bus->queue = NULL;
|
|
g_mutex_unlock (bus->queue_lock);
|
|
g_mutex_free (bus->queue_lock);
|
|
bus->queue_lock = NULL;
|
|
g_cond_free (bus->priv->queue_cond);
|
|
bus->priv->queue_cond = NULL;
|
|
}
|
|
|
|
if (bus->priv->main_context) {
|
|
g_main_context_unref (bus->priv->main_context);
|
|
bus->priv->main_context = NULL;
|
|
}
|
|
|
|
G_OBJECT_CLASS (parent_class)->dispose (object);
|
|
}
|
|
|
|
static void
|
|
gst_bus_wakeup_main_context (GstBus * bus)
|
|
{
|
|
GMainContext *ctx;
|
|
|
|
GST_OBJECT_LOCK (bus);
|
|
if ((ctx = bus->priv->main_context))
|
|
g_main_context_ref (ctx);
|
|
GST_OBJECT_UNLOCK (bus);
|
|
|
|
g_main_context_wakeup (ctx);
|
|
|
|
if (ctx)
|
|
g_main_context_unref (ctx);
|
|
}
|
|
|
|
static void
|
|
gst_bus_set_main_context (GstBus * bus, GMainContext * ctx)
|
|
{
|
|
GST_OBJECT_LOCK (bus);
|
|
|
|
if (bus->priv->main_context != NULL) {
|
|
g_main_context_unref (bus->priv->main_context);
|
|
bus->priv->main_context = NULL;
|
|
}
|
|
|
|
if (ctx != NULL) {
|
|
bus->priv->main_context = g_main_context_ref (ctx);
|
|
}
|
|
|
|
GST_DEBUG_OBJECT (bus, "setting main context to %p, GLib default context: %p",
|
|
ctx, g_main_context_default ());
|
|
|
|
GST_OBJECT_UNLOCK (bus);
|
|
}
|
|
|
|
/**
|
|
* gst_bus_new:
|
|
*
|
|
* Creates a new #GstBus instance.
|
|
*
|
|
* Returns: a new #GstBus instance
|
|
*/
|
|
GstBus *
|
|
gst_bus_new (void)
|
|
{
|
|
GstBus *result;
|
|
|
|
result = g_object_new (gst_bus_get_type (), NULL);
|
|
GST_DEBUG_OBJECT (result, "created new bus");
|
|
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* gst_bus_post:
|
|
* @bus: a #GstBus to post on
|
|
* @message: The #GstMessage to post
|
|
*
|
|
* Post a message on the given bus. Ownership of the message
|
|
* is taken by the bus.
|
|
*
|
|
* Returns: TRUE if the message could be posted, FALSE if the bus is flushing.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
gboolean
|
|
gst_bus_post (GstBus * bus, GstMessage * message)
|
|
{
|
|
GstBusSyncReply reply = GST_BUS_PASS;
|
|
GstBusSyncHandler handler;
|
|
gboolean emit_sync_message;
|
|
gpointer handler_data;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), FALSE);
|
|
g_return_val_if_fail (GST_IS_MESSAGE (message), FALSE);
|
|
|
|
GST_DEBUG_OBJECT (bus, "[msg %p] posting on bus, type %s, %" GST_PTR_FORMAT
|
|
" from source %" GST_PTR_FORMAT,
|
|
message, GST_MESSAGE_TYPE_NAME (message), message->structure,
|
|
message->src);
|
|
|
|
GST_OBJECT_LOCK (bus);
|
|
/* check if the bus is flushing */
|
|
if (GST_OBJECT_FLAG_IS_SET (bus, GST_BUS_FLUSHING))
|
|
goto is_flushing;
|
|
|
|
handler = bus->sync_handler;
|
|
handler_data = bus->sync_handler_data;
|
|
emit_sync_message = bus->priv->num_sync_message_emitters > 0;
|
|
GST_OBJECT_UNLOCK (bus);
|
|
|
|
/* first call the sync handler if it is installed */
|
|
if (handler)
|
|
reply = handler (bus, message, handler_data);
|
|
|
|
/* emit sync-message if requested to do so via
|
|
gst_bus_enable_sync_message_emission. terrible but effective */
|
|
if (emit_sync_message && reply != GST_BUS_DROP
|
|
&& handler != gst_bus_sync_signal_handler)
|
|
gst_bus_sync_signal_handler (bus, message, NULL);
|
|
|
|
/* now see what we should do with the message */
|
|
switch (reply) {
|
|
case GST_BUS_DROP:
|
|
/* drop the message */
|
|
GST_DEBUG_OBJECT (bus, "[msg %p] dropped", message);
|
|
break;
|
|
case GST_BUS_PASS:
|
|
/* pass the message to the async queue, refcount passed in the queue */
|
|
GST_DEBUG_OBJECT (bus, "[msg %p] pushing on async queue", message);
|
|
g_mutex_lock (bus->queue_lock);
|
|
g_queue_push_tail (bus->queue, message);
|
|
g_cond_broadcast (bus->priv->queue_cond);
|
|
g_mutex_unlock (bus->queue_lock);
|
|
GST_DEBUG_OBJECT (bus, "[msg %p] pushed on async queue", message);
|
|
|
|
gst_bus_wakeup_main_context (bus);
|
|
|
|
break;
|
|
case GST_BUS_ASYNC:
|
|
{
|
|
/* async delivery, we need a mutex and a cond to block
|
|
* on */
|
|
GMutex *lock = g_mutex_new ();
|
|
GCond *cond = g_cond_new ();
|
|
|
|
GST_MESSAGE_COND (message) = cond;
|
|
GST_MESSAGE_GET_LOCK (message) = lock;
|
|
|
|
GST_DEBUG_OBJECT (bus, "[msg %p] waiting for async delivery", message);
|
|
|
|
/* now we lock the message mutex, send the message to the async
|
|
* queue. When the message is handled by the app and destroyed,
|
|
* the cond will be signalled and we can continue */
|
|
g_mutex_lock (lock);
|
|
g_mutex_lock (bus->queue_lock);
|
|
g_queue_push_tail (bus->queue, message);
|
|
g_cond_broadcast (bus->priv->queue_cond);
|
|
g_mutex_unlock (bus->queue_lock);
|
|
|
|
gst_bus_wakeup_main_context (bus);
|
|
|
|
/* now block till the message is freed */
|
|
g_cond_wait (cond, lock);
|
|
g_mutex_unlock (lock);
|
|
|
|
GST_DEBUG_OBJECT (bus, "[msg %p] delivered asynchronously", message);
|
|
|
|
g_mutex_free (lock);
|
|
g_cond_free (cond);
|
|
break;
|
|
}
|
|
default:
|
|
g_warning ("invalid return from bus sync handler");
|
|
break;
|
|
}
|
|
return TRUE;
|
|
|
|
/* ERRORS */
|
|
is_flushing:
|
|
{
|
|
GST_DEBUG_OBJECT (bus, "bus is flushing");
|
|
gst_message_unref (message);
|
|
GST_OBJECT_UNLOCK (bus);
|
|
|
|
return FALSE;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_bus_have_pending:
|
|
* @bus: a #GstBus to check
|
|
*
|
|
* Check if there are pending messages on the bus that
|
|
* should be handled.
|
|
*
|
|
* Returns: TRUE if there are messages on the bus to be handled, FALSE
|
|
* otherwise.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
gboolean
|
|
gst_bus_have_pending (GstBus * bus)
|
|
{
|
|
gboolean result;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), FALSE);
|
|
|
|
g_mutex_lock (bus->queue_lock);
|
|
/* see if there is a message on the bus */
|
|
result = !g_queue_is_empty (bus->queue);
|
|
g_mutex_unlock (bus->queue_lock);
|
|
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* gst_bus_set_flushing:
|
|
* @bus: a #GstBus
|
|
* @flushing: whether or not to flush the bus
|
|
*
|
|
* If @flushing, flush out and unref any messages queued in the bus. Releases
|
|
* references to the message origin objects. Will flush future messages until
|
|
* gst_bus_set_flushing() sets @flushing to #FALSE.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
void
|
|
gst_bus_set_flushing (GstBus * bus, gboolean flushing)
|
|
{
|
|
GstMessage *message;
|
|
|
|
GST_OBJECT_LOCK (bus);
|
|
|
|
if (flushing) {
|
|
GST_OBJECT_FLAG_SET (bus, GST_BUS_FLUSHING);
|
|
|
|
GST_DEBUG_OBJECT (bus, "set bus flushing");
|
|
|
|
while ((message = gst_bus_pop (bus)))
|
|
gst_message_unref (message);
|
|
} else {
|
|
GST_DEBUG_OBJECT (bus, "unset bus flushing");
|
|
GST_OBJECT_FLAG_UNSET (bus, GST_BUS_FLUSHING);
|
|
}
|
|
|
|
GST_OBJECT_UNLOCK (bus);
|
|
}
|
|
|
|
/**
|
|
* gst_bus_timed_pop_filtered:
|
|
* @bus: a #GstBus to pop from
|
|
* @timeout: a timeout in nanoseconds, or GST_CLOCK_TIME_NONE to wait forever
|
|
* @types: message types to take into account, GST_MESSAGE_ANY for any type
|
|
*
|
|
* Get a message from the bus whose type matches the message type mask @types,
|
|
* waiting up to the specified timeout (and discarding any messages that do not
|
|
* match the mask provided).
|
|
*
|
|
* If @timeout is 0, this function behaves like gst_bus_pop_filtered(). If
|
|
* @timeout is #GST_CLOCK_TIME_NONE, this function will block forever until a
|
|
* matching message was posted on the bus.
|
|
*
|
|
* Returns: a #GstMessage matching the filter in @types, or NULL if no matching
|
|
* message was found on the bus until the timeout expired.
|
|
* The message is taken from the bus and needs to be unreffed with
|
|
* gst_message_unref() after usage.
|
|
*
|
|
* MT safe.
|
|
*
|
|
* Since: 0.10.15
|
|
*/
|
|
GstMessage *
|
|
gst_bus_timed_pop_filtered (GstBus * bus, GstClockTime timeout,
|
|
GstMessageType types)
|
|
{
|
|
GstMessage *message;
|
|
GTimeVal *timeval, abstimeout;
|
|
gboolean first_round = TRUE;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), NULL);
|
|
g_return_val_if_fail (types != 0, NULL);
|
|
|
|
g_mutex_lock (bus->queue_lock);
|
|
|
|
while (TRUE) {
|
|
GST_LOG_OBJECT (bus, "have %d messages", g_queue_get_length (bus->queue));
|
|
|
|
while ((message = g_queue_pop_head (bus->queue))) {
|
|
GST_DEBUG_OBJECT (bus, "got message %p, %s, type mask is %u",
|
|
message, GST_MESSAGE_TYPE_NAME (message), (guint) types);
|
|
if ((GST_MESSAGE_TYPE (message) & types) != 0) {
|
|
/* exit the loop, we have a message */
|
|
goto beach;
|
|
} else {
|
|
GST_DEBUG_OBJECT (bus, "discarding message, does not match mask");
|
|
gst_message_unref (message);
|
|
message = NULL;
|
|
}
|
|
}
|
|
|
|
/* no need to wait, exit loop */
|
|
if (timeout == 0)
|
|
break;
|
|
|
|
if (timeout == GST_CLOCK_TIME_NONE) {
|
|
/* wait forever */
|
|
timeval = NULL;
|
|
} else if (first_round) {
|
|
glong add = timeout / 1000;
|
|
|
|
if (add == 0)
|
|
/* no need to wait */
|
|
break;
|
|
|
|
/* make timeout absolute */
|
|
g_get_current_time (&abstimeout);
|
|
g_time_val_add (&abstimeout, add);
|
|
timeval = &abstimeout;
|
|
first_round = FALSE;
|
|
GST_DEBUG_OBJECT (bus, "blocking for message, timeout %ld", add);
|
|
} else {
|
|
/* calculated the absolute end time already, no need to do it again */
|
|
GST_DEBUG_OBJECT (bus, "blocking for message, again");
|
|
timeval = &abstimeout; /* fool compiler */
|
|
}
|
|
if (!g_cond_timed_wait (bus->priv->queue_cond, bus->queue_lock, timeval)) {
|
|
GST_INFO_OBJECT (bus, "timed out, breaking loop");
|
|
break;
|
|
} else {
|
|
GST_INFO_OBJECT (bus, "we got woken up, recheck for message");
|
|
}
|
|
}
|
|
|
|
beach:
|
|
|
|
g_mutex_unlock (bus->queue_lock);
|
|
|
|
return message;
|
|
}
|
|
|
|
|
|
/**
|
|
* gst_bus_timed_pop:
|
|
* @bus: a #GstBus to pop
|
|
* @timeout: a timeout
|
|
*
|
|
* Get a message from the bus, waiting up to the specified timeout.
|
|
*
|
|
* If @timeout is 0, this function behaves like gst_bus_pop(). If @timeout is
|
|
* #GST_CLOCK_TIME_NONE, this function will block forever until a message was
|
|
* posted on the bus.
|
|
*
|
|
* Returns: The #GstMessage that is on the bus after the specified timeout
|
|
* or NULL if the bus is empty after the timeout expired.
|
|
* The message is taken from the bus and needs to be unreffed with
|
|
* gst_message_unref() after usage.
|
|
*
|
|
* MT safe.
|
|
*
|
|
* Since: 0.10.12
|
|
*/
|
|
GstMessage *
|
|
gst_bus_timed_pop (GstBus * bus, GstClockTime timeout)
|
|
{
|
|
g_return_val_if_fail (GST_IS_BUS (bus), NULL);
|
|
|
|
return gst_bus_timed_pop_filtered (bus, timeout, GST_MESSAGE_ANY);
|
|
}
|
|
|
|
/**
|
|
* gst_bus_pop_filtered:
|
|
* @bus: a #GstBus to pop
|
|
* @types: message types to take into account
|
|
*
|
|
* Get a message matching @type from the bus. Will discard all messages on
|
|
* the bus that do not match @type and that have been posted before the first
|
|
* message that does match @type. If there is no message matching @type on
|
|
* the bus, all messages will be discarded.
|
|
*
|
|
* Returns: The next #GstMessage matching @type that is on the bus, or NULL if
|
|
* the bus is empty or there is no message matching @type.
|
|
* The message is taken from the bus and needs to be unreffed with
|
|
* gst_message_unref() after usage.
|
|
*
|
|
* MT safe.
|
|
*
|
|
* Since: 0.10.15
|
|
*/
|
|
GstMessage *
|
|
gst_bus_pop_filtered (GstBus * bus, GstMessageType types)
|
|
{
|
|
g_return_val_if_fail (GST_IS_BUS (bus), NULL);
|
|
g_return_val_if_fail (types != 0, NULL);
|
|
|
|
return gst_bus_timed_pop_filtered (bus, 0, types);
|
|
}
|
|
|
|
/**
|
|
* gst_bus_pop:
|
|
* @bus: a #GstBus to pop
|
|
*
|
|
* Get a message from the bus.
|
|
*
|
|
* Returns: The #GstMessage that is on the bus, or NULL if the bus is empty.
|
|
* The message is taken from the bus and needs to be unreffed with
|
|
* gst_message_unref() after usage.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstMessage *
|
|
gst_bus_pop (GstBus * bus)
|
|
{
|
|
g_return_val_if_fail (GST_IS_BUS (bus), NULL);
|
|
|
|
return gst_bus_timed_pop_filtered (bus, 0, GST_MESSAGE_ANY);
|
|
}
|
|
|
|
/**
|
|
* gst_bus_peek:
|
|
* @bus: a #GstBus
|
|
*
|
|
* Peek the message on the top of the bus' queue. The message will remain
|
|
* on the bus' message queue. A reference is returned, and needs to be unreffed
|
|
* by the caller.
|
|
*
|
|
* Returns: The #GstMessage that is on the bus, or NULL if the bus is empty.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
GstMessage *
|
|
gst_bus_peek (GstBus * bus)
|
|
{
|
|
GstMessage *message;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), NULL);
|
|
|
|
g_mutex_lock (bus->queue_lock);
|
|
message = g_queue_peek_head (bus->queue);
|
|
if (message)
|
|
gst_message_ref (message);
|
|
g_mutex_unlock (bus->queue_lock);
|
|
|
|
GST_DEBUG_OBJECT (bus, "peek on bus, got message %p", message);
|
|
|
|
return message;
|
|
}
|
|
|
|
/**
|
|
* gst_bus_set_sync_handler:
|
|
* @bus: a #GstBus to install the handler on
|
|
* @func: The handler function to install
|
|
* @data: User data that will be sent to the handler function.
|
|
*
|
|
* Sets the synchronous handler on the bus. The function will be called
|
|
* every time a new message is posted on the bus. Note that the function
|
|
* will be called in the same thread context as the posting object. This
|
|
* function is usually only called by the creator of the bus. Applications
|
|
* should handle messages asynchronously using the gst_bus watch and poll
|
|
* functions.
|
|
*
|
|
* You cannot replace an existing sync_handler. You can pass NULL to this
|
|
* function, which will clear the existing handler.
|
|
*/
|
|
void
|
|
gst_bus_set_sync_handler (GstBus * bus, GstBusSyncHandler func, gpointer data)
|
|
{
|
|
g_return_if_fail (GST_IS_BUS (bus));
|
|
|
|
GST_OBJECT_LOCK (bus);
|
|
|
|
/* Assert if the user attempts to replace an existing sync_handler,
|
|
* other than to clear it */
|
|
if (func != NULL && bus->sync_handler != NULL)
|
|
goto no_replace;
|
|
|
|
bus->sync_handler = func;
|
|
bus->sync_handler_data = data;
|
|
GST_OBJECT_UNLOCK (bus);
|
|
|
|
return;
|
|
|
|
no_replace:
|
|
{
|
|
GST_OBJECT_UNLOCK (bus);
|
|
g_warning ("cannot replace existing sync handler");
|
|
return;
|
|
}
|
|
}
|
|
|
|
/* GSource for the bus
|
|
*/
|
|
typedef struct
|
|
{
|
|
GSource source;
|
|
GstBus *bus;
|
|
gboolean inited;
|
|
} GstBusSource;
|
|
|
|
static gboolean
|
|
gst_bus_source_prepare (GSource * source, gint * timeout)
|
|
{
|
|
GstBusSource *bsrc = (GstBusSource *) source;
|
|
|
|
/* we do this here now that we know that we're attached to a main context
|
|
* (we don't support detaching a source from a main context and then
|
|
* re-attaching it to a different main context) */
|
|
if (G_UNLIKELY (!bsrc->inited)) {
|
|
gst_bus_set_main_context (bsrc->bus, g_source_get_context (source));
|
|
bsrc->inited = TRUE;
|
|
}
|
|
|
|
*timeout = -1;
|
|
return gst_bus_have_pending (bsrc->bus);
|
|
}
|
|
|
|
static gboolean
|
|
gst_bus_source_check (GSource * source)
|
|
{
|
|
GstBusSource *bsrc = (GstBusSource *) source;
|
|
|
|
return gst_bus_have_pending (bsrc->bus);
|
|
}
|
|
|
|
static gboolean
|
|
gst_bus_source_dispatch (GSource * source, GSourceFunc callback,
|
|
gpointer user_data)
|
|
{
|
|
GstBusFunc handler = (GstBusFunc) callback;
|
|
GstBusSource *bsource = (GstBusSource *) source;
|
|
GstMessage *message;
|
|
gboolean keep;
|
|
GstBus *bus;
|
|
|
|
g_return_val_if_fail (bsource != NULL, FALSE);
|
|
|
|
bus = bsource->bus;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), FALSE);
|
|
|
|
message = gst_bus_pop (bus);
|
|
|
|
/* The message queue might be empty if some other thread or callback set
|
|
* the bus to flushing between check/prepare and dispatch */
|
|
if (G_UNLIKELY (message == NULL))
|
|
return TRUE;
|
|
|
|
if (!handler)
|
|
goto no_handler;
|
|
|
|
GST_DEBUG_OBJECT (bus, "source %p calling dispatch with %p", source, message);
|
|
|
|
keep = handler (bus, message, user_data);
|
|
gst_message_unref (message);
|
|
|
|
GST_DEBUG_OBJECT (bus, "source %p handler returns %d", source, keep);
|
|
|
|
return keep;
|
|
|
|
no_handler:
|
|
{
|
|
g_warning ("GstBus watch dispatched without callback\n"
|
|
"You must call g_source_set_callback().");
|
|
gst_message_unref (message);
|
|
return FALSE;
|
|
}
|
|
}
|
|
|
|
static void
|
|
gst_bus_source_finalize (GSource * source)
|
|
{
|
|
GstBusSource *bsource = (GstBusSource *) source;
|
|
GstBus *bus;
|
|
|
|
bus = bsource->bus;
|
|
|
|
GST_DEBUG_OBJECT (bus, "finalize source %p", source);
|
|
|
|
GST_OBJECT_LOCK (bus);
|
|
if (bus->priv->watch_id == source)
|
|
bus->priv->watch_id = NULL;
|
|
GST_OBJECT_UNLOCK (bus);
|
|
|
|
gst_bus_set_main_context (bsource->bus, NULL);
|
|
gst_object_unref (bsource->bus);
|
|
bsource->bus = NULL;
|
|
}
|
|
|
|
static GSourceFuncs gst_bus_source_funcs = {
|
|
gst_bus_source_prepare,
|
|
gst_bus_source_check,
|
|
gst_bus_source_dispatch,
|
|
gst_bus_source_finalize
|
|
};
|
|
|
|
/**
|
|
* gst_bus_create_watch:
|
|
* @bus: a #GstBus to create the watch for
|
|
*
|
|
* Create watch for this bus. The GSource will be dispatched whenever
|
|
* a message is on the bus. After the GSource is dispatched, the
|
|
* message is popped off the bus and unreffed.
|
|
*
|
|
* Returns: A #GSource that can be added to a mainloop.
|
|
*/
|
|
GSource *
|
|
gst_bus_create_watch (GstBus * bus)
|
|
{
|
|
GstBusSource *source;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), NULL);
|
|
|
|
source = (GstBusSource *) g_source_new (&gst_bus_source_funcs,
|
|
sizeof (GstBusSource));
|
|
source->bus = gst_object_ref (bus);
|
|
source->inited = FALSE;
|
|
|
|
return (GSource *) source;
|
|
}
|
|
|
|
/* must be called with the bus OBJECT LOCK */
|
|
static guint
|
|
gst_bus_add_watch_full_unlocked (GstBus * bus, gint priority,
|
|
GstBusFunc func, gpointer user_data, GDestroyNotify notify)
|
|
{
|
|
guint id;
|
|
GSource *source;
|
|
|
|
if (bus->priv->watch_id) {
|
|
GST_ERROR_OBJECT (bus,
|
|
"Tried to add new watch while one was already there");
|
|
return 0;
|
|
}
|
|
|
|
source = gst_bus_create_watch (bus);
|
|
|
|
if (priority != G_PRIORITY_DEFAULT)
|
|
g_source_set_priority (source, priority);
|
|
|
|
g_source_set_callback (source, (GSourceFunc) func, user_data, notify);
|
|
|
|
id = g_source_attach (source, NULL);
|
|
g_source_unref (source);
|
|
|
|
if (id) {
|
|
bus->priv->watch_id = source;
|
|
}
|
|
|
|
GST_DEBUG_OBJECT (bus, "New source %p with id %u", source, id);
|
|
return id;
|
|
}
|
|
|
|
/**
|
|
* gst_bus_add_watch_full:
|
|
* @bus: a #GstBus to create the watch for.
|
|
* @priority: The priority of the watch.
|
|
* @func: A function to call when a message is received.
|
|
* @user_data: user data passed to @func.
|
|
* @notify: the function to call when the source is removed.
|
|
*
|
|
* Adds a bus watch to the default main context with the given @priority.
|
|
* This function is used to receive asynchronous messages in the main loop.
|
|
* There can only be a single bus watch per bus, you must remove it before you
|
|
* can set a new one.
|
|
*
|
|
* When @func is called, the message belongs to the caller; if you want to
|
|
* keep a copy of it, call gst_message_ref() before leaving @func.
|
|
*
|
|
* The watch can be removed using g_source_remove() or by returning FALSE
|
|
* from @func.
|
|
*
|
|
* Returns: The event source id.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
guint
|
|
gst_bus_add_watch_full (GstBus * bus, gint priority,
|
|
GstBusFunc func, gpointer user_data, GDestroyNotify notify)
|
|
{
|
|
guint id;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), 0);
|
|
|
|
GST_OBJECT_LOCK (bus);
|
|
id = gst_bus_add_watch_full_unlocked (bus, priority, func, user_data, notify);
|
|
GST_OBJECT_UNLOCK (bus);
|
|
|
|
return id;
|
|
}
|
|
|
|
/**
|
|
* gst_bus_add_watch:
|
|
* @bus: a #GstBus to create the watch for
|
|
* @func: A function to call when a message is received.
|
|
* @user_data: user data passed to @func.
|
|
*
|
|
* Adds a bus watch to the default main context with the default priority.
|
|
* This function is used to receive asynchronous messages in the main loop.
|
|
* There can only be a single bus watch per bus, you must remove it before you
|
|
* can set a new one.
|
|
*
|
|
* The watch can be removed using g_source_remove() or by returning FALSE
|
|
* from @func.
|
|
*
|
|
* Returns: The event source id.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
guint
|
|
gst_bus_add_watch (GstBus * bus, GstBusFunc func, gpointer user_data)
|
|
{
|
|
return gst_bus_add_watch_full (bus, G_PRIORITY_DEFAULT, func,
|
|
user_data, NULL);
|
|
}
|
|
|
|
typedef struct
|
|
{
|
|
GMainLoop *loop;
|
|
guint timeout_id;
|
|
gboolean source_running;
|
|
GstMessageType events;
|
|
GstMessage *message;
|
|
} GstBusPollData;
|
|
|
|
static void
|
|
poll_func (GstBus * bus, GstMessage * message, GstBusPollData * poll_data)
|
|
{
|
|
GstMessageType type;
|
|
|
|
if (!g_main_loop_is_running (poll_data->loop)) {
|
|
GST_DEBUG ("mainloop %p not running", poll_data->loop);
|
|
return;
|
|
}
|
|
|
|
type = GST_MESSAGE_TYPE (message);
|
|
|
|
if (type & poll_data->events) {
|
|
g_return_if_fail (poll_data->message == NULL);
|
|
/* keep ref to message */
|
|
poll_data->message = gst_message_ref (message);
|
|
GST_DEBUG ("mainloop %p quit", poll_data->loop);
|
|
g_main_loop_quit (poll_data->loop);
|
|
} else {
|
|
GST_DEBUG ("type %08x does not match %08x", type, poll_data->events);
|
|
}
|
|
}
|
|
|
|
static gboolean
|
|
poll_timeout (GstBusPollData * poll_data)
|
|
{
|
|
GST_DEBUG ("mainloop %p quit", poll_data->loop);
|
|
g_main_loop_quit (poll_data->loop);
|
|
|
|
/* we don't remove the GSource as this would free our poll_data,
|
|
* which we still need */
|
|
return TRUE;
|
|
}
|
|
|
|
static void
|
|
poll_destroy (GstBusPollData * poll_data, gpointer unused)
|
|
{
|
|
poll_data->source_running = FALSE;
|
|
if (!poll_data->timeout_id) {
|
|
g_main_loop_unref (poll_data->loop);
|
|
g_free (poll_data);
|
|
}
|
|
}
|
|
|
|
static void
|
|
poll_destroy_timeout (GstBusPollData * poll_data)
|
|
{
|
|
poll_data->timeout_id = 0;
|
|
if (!poll_data->source_running) {
|
|
g_main_loop_unref (poll_data->loop);
|
|
g_free (poll_data);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_bus_poll:
|
|
* @bus: a #GstBus
|
|
* @events: a mask of #GstMessageType, representing the set of message types to
|
|
* poll for.
|
|
* @timeout: the poll timeout, as a #GstClockTimeDiff, or -1 to poll
|
|
* indefinitely.
|
|
*
|
|
* Poll the bus for messages. Will block while waiting for messages to come.
|
|
* You can specify a maximum time to poll with the @timeout parameter. If
|
|
* @timeout is negative, this function will block indefinitely.
|
|
*
|
|
* All messages not in @events will be popped off the bus and will be ignored.
|
|
*
|
|
* Because poll is implemented using the "message" signal enabled by
|
|
* gst_bus_add_signal_watch(), calling gst_bus_poll() will cause the "message"
|
|
* signal to be emitted for every message that poll sees. Thus a "message"
|
|
* signal handler will see the same messages that this function sees -- neither
|
|
* will steal messages from the other.
|
|
*
|
|
* This function will run a main loop from the default main context when
|
|
* polling.
|
|
*
|
|
* You should never use this function, since it is pure evil. This is
|
|
* especially true for GUI applications based on Gtk+ or Qt, but also for any
|
|
* other non-trivial application that uses the GLib main loop. As this function
|
|
* runs a GLib main loop, any callback attached to the default GLib main
|
|
* context may be invoked. This could be timeouts, GUI events, I/O events etc.;
|
|
* even if gst_bus_poll() is called with a 0 timeout. Any of these callbacks
|
|
* may do things you do not expect, e.g. destroy the main application window or
|
|
* some other resource; change other application state; display a dialog and
|
|
* run another main loop until the user clicks it away. In short, using this
|
|
* function may add a lot of complexity to your code through unexpected
|
|
* re-entrancy and unexpected changes to your application's state.
|
|
*
|
|
* For 0 timeouts use gst_bus_pop_filtered() instead of this function; for
|
|
* other short timeouts use gst_bus_timed_pop_filtered(); everything else is
|
|
* better handled by setting up an asynchronous bus watch and doing things
|
|
* from there.
|
|
*
|
|
* Returns: The message that was received, or NULL if the poll timed out.
|
|
* The message is taken from the bus and needs to be unreffed with
|
|
* gst_message_unref() after usage.
|
|
*/
|
|
GstMessage *
|
|
gst_bus_poll (GstBus * bus, GstMessageType events, GstClockTimeDiff timeout)
|
|
{
|
|
GstBusPollData *poll_data;
|
|
GstMessage *ret;
|
|
gulong id;
|
|
|
|
poll_data = g_new0 (GstBusPollData, 1);
|
|
poll_data->source_running = TRUE;
|
|
poll_data->loop = g_main_loop_new (NULL, FALSE);
|
|
poll_data->events = events;
|
|
poll_data->message = NULL;
|
|
|
|
if (timeout >= 0)
|
|
poll_data->timeout_id = g_timeout_add_full (G_PRIORITY_DEFAULT_IDLE,
|
|
timeout / GST_MSECOND, (GSourceFunc) poll_timeout, poll_data,
|
|
(GDestroyNotify) poll_destroy_timeout);
|
|
else
|
|
poll_data->timeout_id = 0;
|
|
|
|
id = g_signal_connect_data (bus, "message", G_CALLBACK (poll_func), poll_data,
|
|
(GClosureNotify) poll_destroy, 0);
|
|
|
|
/* these can be nested, so it's ok */
|
|
gst_bus_add_signal_watch (bus);
|
|
|
|
GST_DEBUG ("running mainloop %p", poll_data->loop);
|
|
g_main_loop_run (poll_data->loop);
|
|
GST_DEBUG ("mainloop stopped %p", poll_data->loop);
|
|
|
|
gst_bus_remove_signal_watch (bus);
|
|
|
|
/* holds a ref */
|
|
ret = poll_data->message;
|
|
|
|
if (poll_data->timeout_id)
|
|
g_source_remove (poll_data->timeout_id);
|
|
|
|
/* poll_data will be freed now */
|
|
g_signal_handler_disconnect (bus, id);
|
|
|
|
GST_DEBUG_OBJECT (bus, "finished poll with message %p", ret);
|
|
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* gst_bus_async_signal_func:
|
|
* @bus: a #GstBus
|
|
* @message: the #GstMessage received
|
|
* @data: user data
|
|
*
|
|
* A helper #GstBusFunc that can be used to convert all asynchronous messages
|
|
* into signals.
|
|
*
|
|
* Returns: TRUE
|
|
*/
|
|
gboolean
|
|
gst_bus_async_signal_func (GstBus * bus, GstMessage * message, gpointer data)
|
|
{
|
|
GQuark detail = 0;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), TRUE);
|
|
g_return_val_if_fail (message != NULL, TRUE);
|
|
|
|
detail = gst_message_type_to_quark (GST_MESSAGE_TYPE (message));
|
|
|
|
g_signal_emit (bus, gst_bus_signals[ASYNC_MESSAGE], detail, message);
|
|
|
|
/* we never remove this source based on signal emission return values */
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* gst_bus_sync_signal_handler:
|
|
* @bus: a #GstBus
|
|
* @message: the #GstMessage received
|
|
* @data: user data
|
|
*
|
|
* A helper GstBusSyncHandler that can be used to convert all synchronous
|
|
* messages into signals.
|
|
*
|
|
* Returns: GST_BUS_PASS
|
|
*/
|
|
GstBusSyncReply
|
|
gst_bus_sync_signal_handler (GstBus * bus, GstMessage * message, gpointer data)
|
|
{
|
|
GQuark detail = 0;
|
|
|
|
g_return_val_if_fail (GST_IS_BUS (bus), GST_BUS_DROP);
|
|
g_return_val_if_fail (message != NULL, GST_BUS_DROP);
|
|
|
|
detail = gst_message_type_to_quark (GST_MESSAGE_TYPE (message));
|
|
|
|
g_signal_emit (bus, gst_bus_signals[SYNC_MESSAGE], detail, message);
|
|
|
|
return GST_BUS_PASS;
|
|
}
|
|
|
|
/**
|
|
* gst_bus_enable_sync_message_emission:
|
|
* @bus: a #GstBus on which you want to receive the "sync-message" signal
|
|
*
|
|
* Instructs GStreamer to emit the "sync-message" signal after running the bus's
|
|
* sync handler. This function is here so that code can ensure that they can
|
|
* synchronously receive messages without having to affect what the bin's sync
|
|
* handler is.
|
|
*
|
|
* This function may be called multiple times. To clean up, the caller is
|
|
* responsible for calling gst_bus_disable_sync_message_emission() as many times
|
|
* as this function is called.
|
|
*
|
|
* While this function looks similar to gst_bus_add_signal_watch(), it is not
|
|
* exactly the same -- this function enables <emphasis>synchronous</emphasis> emission of
|
|
* signals when messages arrive; gst_bus_add_signal_watch() adds an idle callback
|
|
* to pop messages off the bus <emphasis>asynchronously</emphasis>. The sync-message signal
|
|
* comes from the thread of whatever object posted the message; the "message"
|
|
* signal is marshalled to the main thread via the main loop.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
void
|
|
gst_bus_enable_sync_message_emission (GstBus * bus)
|
|
{
|
|
g_return_if_fail (GST_IS_BUS (bus));
|
|
|
|
GST_OBJECT_LOCK (bus);
|
|
bus->priv->num_sync_message_emitters++;
|
|
GST_OBJECT_UNLOCK (bus);
|
|
}
|
|
|
|
/**
|
|
* gst_bus_disable_sync_message_emission:
|
|
* @bus: a #GstBus on which you previously called
|
|
* gst_bus_enable_sync_message_emission()
|
|
*
|
|
* Instructs GStreamer to stop emitting the "sync-message" signal for this bus.
|
|
* See gst_bus_enable_sync_message_emission() for more information.
|
|
*
|
|
* In the event that multiple pieces of code have called
|
|
* gst_bus_enable_sync_message_emission(), the sync-message emissions will only
|
|
* be stopped after all calls to gst_bus_enable_sync_message_emission() were
|
|
* "cancelled" by calling this function. In this way the semantics are exactly
|
|
* the same as gst_object_ref() that which calls enable should also call
|
|
* disable.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
void
|
|
gst_bus_disable_sync_message_emission (GstBus * bus)
|
|
{
|
|
g_return_if_fail (GST_IS_BUS (bus));
|
|
g_return_if_fail (bus->num_signal_watchers == 0);
|
|
|
|
GST_OBJECT_LOCK (bus);
|
|
bus->priv->num_sync_message_emitters--;
|
|
GST_OBJECT_UNLOCK (bus);
|
|
}
|
|
|
|
/**
|
|
* gst_bus_add_signal_watch_full:
|
|
* @bus: a #GstBus on which you want to receive the "message" signal
|
|
* @priority: The priority of the watch.
|
|
*
|
|
* Adds a bus signal watch to the default main context with the given priority.
|
|
* After calling this statement, the bus will emit the "message" signal for each
|
|
* message posted on the bus when the main loop is running.
|
|
*
|
|
* 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.
|
|
*
|
|
* There can only be a single bus watch per bus, you most remove all signal watch
|
|
* before you can set another type of watch.
|
|
*
|
|
* MT safe.
|
|
*/
|
|
void
|
|
gst_bus_add_signal_watch_full (GstBus * bus, gint priority)
|
|
{
|
|
g_return_if_fail (GST_IS_BUS (bus));
|
|
|
|
/* I know the callees don't take this lock, so go ahead and abuse it */
|
|
GST_OBJECT_LOCK (bus);
|
|
|
|
if (bus->num_signal_watchers > 0)
|
|
goto done;
|
|
|
|
/* this should not fail because the counter above takes care of it */
|
|
g_assert (bus->signal_watch_id == 0);
|
|
|
|
bus->signal_watch_id =
|
|
gst_bus_add_watch_full_unlocked (bus, priority, gst_bus_async_signal_func,
|
|
NULL, NULL);
|
|
|
|
if (G_UNLIKELY (bus->signal_watch_id == 0))
|
|
goto add_failed;
|
|
|
|
done:
|
|
|
|
bus->num_signal_watchers++;
|
|
|
|
GST_OBJECT_UNLOCK (bus);
|
|
return;
|
|
|
|
/* ERRORS */
|
|
add_failed:
|
|
{
|
|
g_critical ("Could not add signal watch to bus %s", GST_OBJECT_NAME (bus));
|
|
GST_OBJECT_UNLOCK (bus);
|
|
return;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* gst_bus_add_signal_watch:
|
|
* @bus: a #GstBus on which you want to receive 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.
|
|
*
|
|
* 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.
|
|
*/
|
|
void
|
|
gst_bus_add_signal_watch (GstBus * bus)
|
|
{
|
|
gst_bus_add_signal_watch_full (bus, G_PRIORITY_DEFAULT);
|
|
}
|
|
|
|
/**
|
|
* 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)
|
|
{
|
|
guint id = 0;
|
|
|
|
g_return_if_fail (GST_IS_BUS (bus));
|
|
|
|
/* I know the callees don't take this lock, so go ahead and abuse it */
|
|
GST_OBJECT_LOCK (bus);
|
|
|
|
if (bus->num_signal_watchers == 0)
|
|
goto error;
|
|
|
|
bus->num_signal_watchers--;
|
|
|
|
if (bus->num_signal_watchers > 0)
|
|
goto done;
|
|
|
|
id = bus->signal_watch_id;
|
|
bus->signal_watch_id = 0;
|
|
|
|
GST_DEBUG_OBJECT (bus, "removing signal watch %u", id);
|
|
|
|
done:
|
|
GST_OBJECT_UNLOCK (bus);
|
|
|
|
if (id)
|
|
g_source_remove (id);
|
|
|
|
return;
|
|
|
|
/* ERRORS */
|
|
error:
|
|
{
|
|
g_critical ("Bus %s has no signal watches attached", GST_OBJECT_NAME (bus));
|
|
GST_OBJECT_UNLOCK (bus);
|
|
return;
|
|
}
|
|
}
|