gstreamer/gst/gstbin.h
Sebastian Dröge 8177173db0 element: Add gst_element_call_async()
This calls a function from another thread, asynchronously. This is to be
used for cases when a state change has to be performed from a streaming
thread, directly via gst_element_set_state() or indirectly e.g. via SEEK
events.

Calling those functions directly from the streaming thread will cause
deadlocks in many situations, as they might involve waiting for the
streaming thread to shut down from this very streaming thread.

This is mostly a convenience function around a GThreadPool and is for example
used by GstBin to continue asynchronous state changes.

https://bugzilla.gnome.org/show_bug.cgi?id=760532
2016-04-27 18:51:33 +03:00

208 lines
6.5 KiB
C

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
*
* gstbin.h: Header for GstBin container object
*
* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_BIN_H__
#define __GST_BIN_H__
#include <gst/gstelement.h>
#include <gst/gstiterator.h>
#include <gst/gstbus.h>
G_BEGIN_DECLS
#define GST_TYPE_BIN (gst_bin_get_type ())
#define GST_IS_BIN(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_BIN))
#define GST_IS_BIN_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_BIN))
#define GST_BIN_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_BIN, GstBinClass))
#define GST_BIN(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_BIN, GstBin))
#define GST_BIN_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_BIN, GstBinClass))
#define GST_BIN_CAST(obj) ((GstBin*)(obj))
/**
* GstBinFlags:
* @GST_BIN_FLAG_NO_RESYNC: don't resync a state change when elements are
* added or linked in the bin (Since 1.0.5)
* @GST_BIN_FLAG_LAST: the last enum in the series of flags for bins.
* Derived classes can use this as first value in a list of flags.
*
* GstBinFlags are a set of flags specific to bins. Most are set/used
* internally. They can be checked using the GST_OBJECT_FLAG_IS_SET () macro,
* and (un)set using GST_OBJECT_FLAG_SET () and GST_OBJECT_FLAG_UNSET ().
*/
typedef enum {
GST_BIN_FLAG_NO_RESYNC = (GST_ELEMENT_FLAG_LAST << 0),
/* padding */
GST_BIN_FLAG_LAST = (GST_ELEMENT_FLAG_LAST << 5)
} GstBinFlags;
/**
* GST_BIN_IS_NO_RESYNC:
* @bin: A #GstBin
*
* Check if @bin will resync its state change when elements are added and
* removed.
*
* Since: 1.0.5
*/
#define GST_BIN_IS_NO_RESYNC(bin) (GST_OBJECT_FLAG_IS_SET(bin,GST_BIN_FLAG_NO_RESYNC))
typedef struct _GstBin GstBin;
typedef struct _GstBinClass GstBinClass;
typedef struct _GstBinPrivate GstBinPrivate;
/**
* GST_BIN_NUMCHILDREN:
* @bin: a #GstBin
*
* Gets the number of children in a bin.
*/
#define GST_BIN_NUMCHILDREN(bin) (GST_BIN_CAST(bin)->numchildren)
/**
* GST_BIN_CHILDREN:
* @bin: a #GstBin
*
* Gets the list with children in a bin.
*/
#define GST_BIN_CHILDREN(bin) (GST_BIN_CAST(bin)->children)
/**
* GST_BIN_CHILDREN_COOKIE:
* @bin: a #GstBin
*
* Gets the children cookie that watches the children list.
*/
#define GST_BIN_CHILDREN_COOKIE(bin) (GST_BIN_CAST(bin)->children_cookie)
/**
* GstBin:
* @numchildren: the number of children in this bin
* @children: (element-type Gst.Element): the list of children in this bin
* @children_cookie: updated whenever @children changes
* @child_bus: internal bus for handling child messages
* @messages: (element-type Gst.Message): queued and cached messages
* @polling: the bin is currently calculating its state
* @state_dirty: the bin needs to recalculate its state (deprecated)
* @clock_dirty: the bin needs to select a new clock
* @provided_clock: the last clock selected
* @clock_provider: the element that provided @provided_clock
*
* The GstBin base class. Subclasses can access these fields provided
* the LOCK is taken.
*/
struct _GstBin {
GstElement element;
/*< public >*/ /* with LOCK */
/* our children, subclass are supposed to update these
* fields to reflect their state with _iterate_*() */
gint numchildren;
GList *children;
guint32 children_cookie;
GstBus *child_bus;
GList *messages;
gboolean polling;
gboolean state_dirty;
gboolean clock_dirty;
GstClock *provided_clock;
GstElement *clock_provider;
/*< private >*/
GstBinPrivate *priv;
gpointer _gst_reserved[GST_PADDING];
};
/**
* GstBinClass:
* @parent_class: bin parent class
* @add_element: method to add an element to a bin
* @remove_element: method to remove an element from a bin
* @handle_message: method to handle a message from the children
*
* Subclasses can override the @add_element and @remove_element to
* update the list of children in the bin.
*
* The @handle_message method can be overridden to implement custom
* message handling. @handle_message takes ownership of the message, just like
* #gst_element_post_message.
*/
struct _GstBinClass {
GstElementClass parent_class;
/*< private >*/
GThreadPool *pool; /* deprecated */
/* signals */
void (*element_added) (GstBin *bin, GstElement *child);
void (*element_removed) (GstBin *bin, GstElement *child);
/*< public >*/
/* virtual methods for subclasses */
gboolean (*add_element) (GstBin *bin, GstElement *element);
gboolean (*remove_element) (GstBin *bin, GstElement *element);
void (*handle_message) (GstBin *bin, GstMessage *message);
/*< private >*/
/* signal */
gboolean (*do_latency) (GstBin *bin);
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GType gst_bin_get_type (void);
GstElement* gst_bin_new (const gchar *name);
/* add and remove elements from the bin */
gboolean gst_bin_add (GstBin *bin, GstElement *element);
gboolean gst_bin_remove (GstBin *bin, GstElement *element);
/* retrieve a single child */
GstElement* gst_bin_get_by_name (GstBin *bin, const gchar *name);
GstElement* gst_bin_get_by_name_recurse_up (GstBin *bin, const gchar *name);
GstElement* gst_bin_get_by_interface (GstBin *bin, GType iface);
/* retrieve multiple children */
GstIterator* gst_bin_iterate_elements (GstBin *bin);
GstIterator* gst_bin_iterate_sorted (GstBin *bin);
GstIterator* gst_bin_iterate_recurse (GstBin *bin);
GstIterator* gst_bin_iterate_sinks (GstBin *bin);
GstIterator* gst_bin_iterate_sources (GstBin *bin);
GstIterator* gst_bin_iterate_all_by_interface (GstBin *bin, GType iface);
/* latency */
gboolean gst_bin_recalculate_latency (GstBin * bin);
#ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstBin, gst_object_unref)
#endif
G_END_DECLS
#endif /* __GST_BIN_H__ */