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Move the locking methods from GstMemory to GstMiniObject. Add a miniobject flag to enable LOCKABLE objects. LOCKABLE objects can use the lock/unlock API to control the access to the object. Add a minobject flag that allows you to lock an object in readonly mode. Modify the _is_writable() method to check the shared counter for LOCKABLE objects. This allows us to control writability separately from the refcount for LOCKABLE objects.
750 lines
21 KiB
C
750 lines
21 KiB
C
/* GStreamer
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* Copyright (C) 2005 David Schleef <ds@schleef.org>
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*
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* gstminiobject.h: Header for GstMiniObject
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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/**
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* SECTION:gstminiobject
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* @short_description: Lightweight base class for the GStreamer object hierarchy
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*
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* #GstMiniObject is a simple structure that can be used to implement refcounted
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* types.
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*
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* Subclasses will include #GstMiniObject as the first member in their structure
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* and then call gst_mini_object_init() to initialize the #GstMiniObject fields.
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*
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* gst_mini_object_ref() and gst_mini_object_unref() increment and decrement the
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* refcount respectively. When the refcount of a mini-object reaches 0, the
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* dispose function is called first and when this returns %TRUE, the free
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* function of the miniobject is called.
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*
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* A copy can be made with gst_mini_object_copy().
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*
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* gst_mini_object_is_writable() will return %TRUE when the refcount of the
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* object is exactly 1, meaning the current caller has the only reference to the
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* object. gst_mini_object_make_writable() will return a writable version of the
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* object, which might be a new copy when the refcount was not 1.
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*
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* Opaque data can be associated with a #GstMiniObject with
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* gst_mini_object_set_qdata() and gst_mini_object_get_qdata(). The data is
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* meant to be specific to the particular object and is not automatically copied
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* with gst_mini_object_copy() or similar methods.
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*
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* A weak reference can be added and remove with gst_mini_object_weak_ref()
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* and gst_mini_object_weak_unref() respectively.
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*
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* Last reviewed on 2012-06-15 (0.11.93)
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*/
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#ifdef HAVE_CONFIG_H
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#include "config.h"
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#endif
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#include "gst/gst_private.h"
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#include "gst/gstminiobject.h"
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#include "gst/gstinfo.h"
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#include <gobject/gvaluecollector.h>
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#ifndef GST_DISABLE_TRACE
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#include "gsttrace.h"
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static GstAllocTrace *_gst_mini_object_trace;
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#endif
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/* Mutex used for weak referencing */
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G_LOCK_DEFINE_STATIC (qdata_mutex);
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static GQuark weak_ref_quark;
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#define SHARE_ONE (1 << 16)
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#define SHARE_MASK (~(SHARE_ONE - 1))
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#define LOCK_ONE (GST_LOCK_FLAG_LAST)
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#define FLAG_MASK (GST_LOCK_FLAG_LAST - 1)
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#define LOCK_MASK ((SHARE_ONE - 1) - FLAG_MASK)
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#define LOCK_FLAG_MASK (SHARE_ONE - 1)
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typedef struct
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{
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GQuark quark;
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GstMiniObjectNotify notify;
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gpointer data;
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GDestroyNotify destroy;
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} GstQData;
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#define QDATA(o,i) ((GstQData *)(o)->qdata)[(i)]
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#define QDATA_QUARK(o,i) (QDATA(o,i).quark)
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#define QDATA_NOTIFY(o,i) (QDATA(o,i).notify)
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#define QDATA_DATA(o,i) (QDATA(o,i).data)
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#define QDATA_DESTROY(o,i) (QDATA(o,i).destroy)
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void
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_priv_gst_mini_object_initialize (void)
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{
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weak_ref_quark = g_quark_from_static_string ("GstMiniObjectWeakRefQuark");
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#ifndef GST_DISABLE_TRACE
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_gst_mini_object_trace = _gst_alloc_trace_register ("GstMiniObject", 0);
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#endif
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}
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/**
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* gst_mini_object_init: (skip)
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* @mini_object: a #GstMiniObject
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* @type: the #GType of the mini-object to create
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* @copy_func: the copy function, or NULL
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* @dispose_func: the dispose function, or NULL
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* @free_func: the free function or NULL
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*
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* Initializes a mini-object with the desired type and copy/dispose/free
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* functions.
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*
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* MT safe
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*
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* Returns: (transfer full): the new mini-object.
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*/
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void
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gst_mini_object_init (GstMiniObject * mini_object, guint flags, GType type,
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GstMiniObjectCopyFunction copy_func,
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GstMiniObjectDisposeFunction dispose_func,
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GstMiniObjectFreeFunction free_func)
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{
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mini_object->type = type;
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mini_object->refcount = 1;
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mini_object->lockstate =
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(flags & GST_MINI_OBJECT_FLAG_LOCK_READONLY ? GST_LOCK_FLAG_READ : 0);
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mini_object->flags = flags;
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mini_object->copy = copy_func;
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mini_object->dispose = dispose_func;
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mini_object->free = free_func;
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mini_object->n_qdata = 0;
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mini_object->qdata = NULL;
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#ifndef GST_DISABLE_TRACE
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_gst_alloc_trace_new (_gst_mini_object_trace, mini_object);
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#endif
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}
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/**
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* gst_mini_object_copy:
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* @mini_object: the mini-object to copy
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*
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* Creates a copy of the mini-object.
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*
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* MT safe
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*
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* Returns: (transfer full): the new mini-object.
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*/
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GstMiniObject *
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gst_mini_object_copy (const GstMiniObject * mini_object)
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{
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GstMiniObject *copy;
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g_return_val_if_fail (mini_object != NULL, NULL);
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if (mini_object->copy)
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copy = mini_object->copy (mini_object);
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else
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copy = NULL;
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return copy;
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}
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/**
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* gst_mini_object_lock:
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* @object: the mini-object to lock
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* @flags: #GstLockFlags
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*
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* Lock the mini-object with the specified access mode in @flags.
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*
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* Returns: %TRUE if @object could be locked.
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*/
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gboolean
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gst_mini_object_lock (GstMiniObject * object, GstLockFlags flags)
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{
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gint access_mode, state, newstate;
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g_return_val_if_fail (object != NULL, FALSE);
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g_return_val_if_fail (GST_MINI_OBJECT_IS_LOCKABLE (object), FALSE);
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access_mode = flags & FLAG_MASK;
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do {
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newstate = state = g_atomic_int_get (&object->lockstate);
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GST_CAT_TRACE (GST_CAT_LOCKING, "lock %p: state %08x, access_mode %d",
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object, state, access_mode);
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if (access_mode & GST_LOCK_FLAG_EXCLUSIVE) {
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/* shared ref */
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newstate += SHARE_ONE;
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access_mode &= ~GST_LOCK_FLAG_EXCLUSIVE;
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}
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if (access_mode) {
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if ((state & LOCK_FLAG_MASK) == 0) {
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/* shared counter > 1 and write access */
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if (state > SHARE_ONE && access_mode & GST_LOCK_FLAG_WRITE)
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goto lock_failed;
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/* nothing mapped, set access_mode */
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newstate |= access_mode;
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} else {
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/* access_mode must match */
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if ((state & access_mode) != access_mode)
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goto lock_failed;
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}
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/* increase refcount */
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newstate += LOCK_ONE;
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}
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} while (!g_atomic_int_compare_and_exchange (&object->lockstate, state,
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newstate));
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return TRUE;
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lock_failed:
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{
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GST_CAT_DEBUG (GST_CAT_LOCKING,
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"lock failed %p: state %08x, access_mode %d", object, state,
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access_mode);
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return FALSE;
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}
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}
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/**
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* gst_mini_object_unlock:
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* @object: the mini-object to unlock
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* @flags: #GstLockFlags
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*
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* Unlock the mini-object with the specified access mode in @flags.
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*/
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void
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gst_mini_object_unlock (GstMiniObject * object, GstLockFlags flags)
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{
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gint access_mode, state, newstate;
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g_return_if_fail (object != NULL);
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g_return_if_fail (GST_MINI_OBJECT_IS_LOCKABLE (object));
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access_mode = flags & FLAG_MASK;
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do {
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newstate = state = g_atomic_int_get (&object->lockstate);
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GST_CAT_TRACE (GST_CAT_LOCKING, "unlock %p: state %08x, access_mode %d",
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object, state, access_mode);
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if (access_mode & GST_LOCK_FLAG_EXCLUSIVE) {
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/* shared counter */
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g_return_if_fail (state >= SHARE_ONE);
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newstate -= SHARE_ONE;
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access_mode &= ~GST_LOCK_FLAG_EXCLUSIVE;
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}
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if (access_mode) {
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g_return_if_fail ((state & access_mode) == access_mode);
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/* decrease the refcount */
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newstate -= LOCK_ONE;
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/* last refcount, unset access_mode */
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if ((newstate & LOCK_FLAG_MASK) == access_mode)
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newstate &= ~LOCK_FLAG_MASK;
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}
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} while (!g_atomic_int_compare_and_exchange (&object->lockstate, state,
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newstate));
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}
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/**
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* gst_mini_object_is_writable:
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* @mini_object: the mini-object to check
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*
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* If @mini_object has the LOCKABLE flag set, check if the current EXCLUSIVE
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* lock on @object is the only one, this means that changes to the object will
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* not be visible to any other object.
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*
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* If the LOCKABLE flag is not set, check if the refcount of @mini_object is
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* exactly 1, meaning that no other reference exists to the object and that the
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* object is therefore writable.
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*
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* Modification of a mini-object should only be done after verifying that it
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* is writable.
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*
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* Returns: TRUE if the object is writable.
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*/
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gboolean
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gst_mini_object_is_writable (const GstMiniObject * mini_object)
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{
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gboolean result;
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g_return_val_if_fail (mini_object != NULL, FALSE);
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if (GST_MINI_OBJECT_IS_LOCKABLE (mini_object)) {
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result = (g_atomic_int_get (&mini_object->lockstate) & SHARE_MASK) < 2;
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} else {
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result = (GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) == 1);
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}
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return result;
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}
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/**
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* gst_mini_object_make_writable:
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* @mini_object: (transfer full): the mini-object to make writable
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*
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* Checks if a mini-object is writable. If not, a writable copy is made and
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* returned. This gives away the reference to the original mini object,
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* and returns a reference to the new object.
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*
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* MT safe
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*
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* Returns: (transfer full): a mini-object (possibly the same pointer) that
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* is writable.
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*/
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GstMiniObject *
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gst_mini_object_make_writable (GstMiniObject * mini_object)
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{
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GstMiniObject *ret;
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g_return_val_if_fail (mini_object != NULL, NULL);
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if (gst_mini_object_is_writable (mini_object)) {
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ret = mini_object;
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} else {
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ret = gst_mini_object_copy (mini_object);
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GST_CAT_DEBUG (GST_CAT_PERFORMANCE, "copy %s miniobject %p -> %p",
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g_type_name (GST_MINI_OBJECT_TYPE (mini_object)), mini_object, ret);
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gst_mini_object_unref (mini_object);
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}
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return ret;
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}
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/**
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* gst_mini_object_ref:
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* @mini_object: the mini-object
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*
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* Increase the reference count of the mini-object.
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*
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* Note that the refcount affects the writeability
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* of @mini-object, see gst_mini_object_is_writable(). It is
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* important to note that keeping additional references to
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* GstMiniObject instances can potentially increase the number
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* of memcpy operations in a pipeline, especially if the miniobject
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* is a #GstBuffer.
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*
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* Returns: (transfer full): the mini-object.
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*/
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GstMiniObject *
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gst_mini_object_ref (GstMiniObject * mini_object)
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{
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g_return_val_if_fail (mini_object != NULL, NULL);
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/* we can't assert that the refcount > 0 since the _free functions
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* increments the refcount from 0 to 1 again to allow resurecting
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* the object
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g_return_val_if_fail (mini_object->refcount > 0, NULL);
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*/
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GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p ref %d->%d", mini_object,
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GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object),
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GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) + 1);
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g_atomic_int_inc (&mini_object->refcount);
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return mini_object;
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}
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static gint
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find_notify (GstMiniObject * object, GQuark quark, gboolean match_notify,
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GstMiniObjectNotify notify, gpointer data)
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{
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guint i;
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for (i = 0; i < object->n_qdata; i++) {
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if (QDATA_QUARK (object, i) == quark) {
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/* check if we need to match the callback too */
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if (!match_notify || (QDATA_NOTIFY (object, i) == notify &&
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QDATA_DATA (object, i) == data))
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return i;
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}
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}
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return -1;
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}
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static void
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remove_notify (GstMiniObject * object, gint index)
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{
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/* remove item */
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if (--object->n_qdata == 0) {
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/* we don't shrink but free when everything is gone */
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g_free (object->qdata);
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object->qdata = NULL;
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} else if (index != object->n_qdata)
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QDATA (object, index) = QDATA (object, object->n_qdata);
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}
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static void
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set_notify (GstMiniObject * object, gint index, GQuark quark,
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GstMiniObjectNotify notify, gpointer data, GDestroyNotify destroy)
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{
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if (index == -1) {
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/* add item */
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index = object->n_qdata++;
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object->qdata =
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g_realloc (object->qdata, sizeof (GstQData) * object->n_qdata);
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}
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QDATA_QUARK (object, index) = quark;
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QDATA_NOTIFY (object, index) = notify;
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QDATA_DATA (object, index) = data;
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QDATA_DESTROY (object, index) = destroy;
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}
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static void
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call_finalize_notify (GstMiniObject * obj)
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{
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guint i;
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for (i = 0; i < obj->n_qdata; i++) {
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if (QDATA_QUARK (obj, i) == weak_ref_quark)
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QDATA_NOTIFY (obj, i) (QDATA_DATA (obj, i), obj);
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if (QDATA_DESTROY (obj, i))
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QDATA_DESTROY (obj, i) (QDATA_DATA (obj, i));
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}
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}
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/**
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* gst_mini_object_unref:
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* @mini_object: the mini-object
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*
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* Decreases the reference count of the mini-object, possibly freeing
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* the mini-object.
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*/
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void
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gst_mini_object_unref (GstMiniObject * mini_object)
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{
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g_return_if_fail (mini_object != NULL);
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GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p unref %d->%d",
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mini_object,
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GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object),
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GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) - 1);
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g_return_if_fail (mini_object->refcount > 0);
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if (G_UNLIKELY (g_atomic_int_dec_and_test (&mini_object->refcount))) {
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gboolean do_free;
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if (mini_object->dispose)
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do_free = mini_object->dispose (mini_object);
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else
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do_free = TRUE;
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/* if the subclass recycled the object (and returned FALSE) we don't
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* want to free the instance anymore */
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if (G_LIKELY (do_free)) {
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/* there should be no outstanding locks */
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g_return_if_fail ((g_atomic_int_get (&mini_object->lockstate) & LOCK_MASK)
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< 4);
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if (mini_object->n_qdata) {
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call_finalize_notify (mini_object);
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g_free (mini_object->qdata);
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}
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#ifndef GST_DISABLE_TRACE
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_gst_alloc_trace_free (_gst_mini_object_trace, mini_object);
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#endif
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if (mini_object->free)
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mini_object->free (mini_object);
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}
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}
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}
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/**
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* gst_mini_object_replace:
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* @olddata: (inout) (transfer full): pointer to a pointer to a mini-object to
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* be replaced
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* @newdata: pointer to new mini-object
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*
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* Atomically modifies a pointer to point to a new mini-object.
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* The reference count of @olddata is decreased and the reference count of
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* @newdata is increased.
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*
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* Either @newdata and the value pointed to by @olddata may be NULL.
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*
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* Returns: TRUE if @newdata was different from @olddata
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*/
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gboolean
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gst_mini_object_replace (GstMiniObject ** olddata, GstMiniObject * newdata)
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{
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GstMiniObject *olddata_val;
|
|
|
|
g_return_val_if_fail (olddata != NULL, FALSE);
|
|
|
|
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "replace %p (%d) with %p (%d)",
|
|
*olddata, *olddata ? (*olddata)->refcount : 0,
|
|
newdata, newdata ? newdata->refcount : 0);
|
|
|
|
olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
|
|
|
|
if (G_UNLIKELY (olddata_val == newdata))
|
|
return FALSE;
|
|
|
|
if (newdata)
|
|
gst_mini_object_ref (newdata);
|
|
|
|
while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
|
|
olddata, olddata_val, newdata))) {
|
|
olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
|
|
if (G_UNLIKELY (olddata_val == newdata))
|
|
break;
|
|
}
|
|
|
|
if (olddata_val)
|
|
gst_mini_object_unref (olddata_val);
|
|
|
|
return olddata_val != newdata;
|
|
}
|
|
|
|
/**
|
|
* gst_mini_object_steal:
|
|
* @olddata: (inout) (transfer full): pointer to a pointer to a mini-object to
|
|
* be stolen
|
|
*
|
|
* Replace the current #GstMiniObject pointer to by @olddata with NULL and
|
|
* return the old value.
|
|
*
|
|
* Returns: the #GstMiniObject at @oldata
|
|
*/
|
|
GstMiniObject *
|
|
gst_mini_object_steal (GstMiniObject ** olddata)
|
|
{
|
|
GstMiniObject *olddata_val;
|
|
|
|
g_return_val_if_fail (olddata != NULL, NULL);
|
|
|
|
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "steal %p (%d)",
|
|
*olddata, *olddata ? (*olddata)->refcount : 0);
|
|
|
|
do {
|
|
olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
|
|
if (olddata_val == NULL)
|
|
break;
|
|
} while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
|
|
olddata, olddata_val, NULL)));
|
|
|
|
return olddata_val;
|
|
}
|
|
|
|
/**
|
|
* gst_mini_object_take:
|
|
* @olddata: (inout) (transfer full): pointer to a pointer to a mini-object to
|
|
* be replaced
|
|
* @newdata: pointer to new mini-object
|
|
*
|
|
* Modifies a pointer to point to a new mini-object. The modification
|
|
* is done atomically. This version is similar to gst_mini_object_replace()
|
|
* except that it does not increase the refcount of @newdata and thus
|
|
* takes ownership of @newdata.
|
|
*
|
|
* Either @newdata and the value pointed to by @olddata may be NULL.
|
|
*
|
|
* Returns: TRUE if @newdata was different from @olddata
|
|
*/
|
|
gboolean
|
|
gst_mini_object_take (GstMiniObject ** olddata, GstMiniObject * newdata)
|
|
{
|
|
GstMiniObject *olddata_val;
|
|
|
|
g_return_val_if_fail (olddata != NULL, FALSE);
|
|
|
|
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "take %p (%d) with %p (%d)",
|
|
*olddata, *olddata ? (*olddata)->refcount : 0,
|
|
newdata, newdata ? newdata->refcount : 0);
|
|
|
|
do {
|
|
olddata_val = g_atomic_pointer_get ((gpointer *) olddata);
|
|
if (G_UNLIKELY (olddata_val == newdata))
|
|
break;
|
|
} while (G_UNLIKELY (!g_atomic_pointer_compare_and_exchange ((gpointer *)
|
|
olddata, olddata_val, newdata)));
|
|
|
|
if (olddata_val)
|
|
gst_mini_object_unref (olddata_val);
|
|
|
|
return olddata_val != newdata;
|
|
}
|
|
|
|
/**
|
|
* gst_mini_object_weak_ref: (skip)
|
|
* @object: #GstMiniObject to reference weakly
|
|
* @notify: callback to invoke before the mini object is freed
|
|
* @data: extra data to pass to notify
|
|
*
|
|
* Adds a weak reference callback to a mini object. Weak references are
|
|
* used for notification when a mini object is finalized. They are called
|
|
* "weak references" because they allow you to safely hold a pointer
|
|
* to the mini object without calling gst_mini_object_ref()
|
|
* (gst_mini_object_ref() adds a strong reference, that is, forces the object
|
|
* to stay alive).
|
|
*
|
|
* Since: 0.10.35
|
|
*/
|
|
void
|
|
gst_mini_object_weak_ref (GstMiniObject * object,
|
|
GstMiniObjectNotify notify, gpointer data)
|
|
{
|
|
g_return_if_fail (object != NULL);
|
|
g_return_if_fail (notify != NULL);
|
|
g_return_if_fail (GST_MINI_OBJECT_REFCOUNT_VALUE (object) >= 1);
|
|
|
|
G_LOCK (qdata_mutex);
|
|
set_notify (object, -1, weak_ref_quark, notify, data, NULL);
|
|
G_UNLOCK (qdata_mutex);
|
|
}
|
|
|
|
/**
|
|
* gst_mini_object_weak_unref: (skip)
|
|
* @object: #GstMiniObject to remove a weak reference from
|
|
* @notify: callback to search for
|
|
* @data: data to search for
|
|
*
|
|
* Removes a weak reference callback from a mini object.
|
|
*
|
|
* Since: 0.10.35
|
|
*/
|
|
void
|
|
gst_mini_object_weak_unref (GstMiniObject * object,
|
|
GstMiniObjectNotify notify, gpointer data)
|
|
{
|
|
gint i;
|
|
|
|
g_return_if_fail (object != NULL);
|
|
g_return_if_fail (notify != NULL);
|
|
|
|
G_LOCK (qdata_mutex);
|
|
if ((i = find_notify (object, weak_ref_quark, TRUE, notify, data)) != -1) {
|
|
remove_notify (object, i);
|
|
} else {
|
|
g_warning ("%s: couldn't find weak ref %p(%p)", G_STRFUNC, notify, data);
|
|
}
|
|
G_UNLOCK (qdata_mutex);
|
|
}
|
|
|
|
/**
|
|
* gst_mini_object_set_qdata:
|
|
* @object: a #GstMiniObject
|
|
* @quark: A #GQuark, naming the user data pointer
|
|
* @data: An opaque user data pointer
|
|
* @destroy: Function to invoke with @data as argument, when @data
|
|
* needs to be freed
|
|
*
|
|
* This sets an opaque, named pointer on a miniobject.
|
|
* The name is specified through a #GQuark (retrived e.g. via
|
|
* g_quark_from_static_string()), and the pointer
|
|
* can be gotten back from the @object with gst_mini_object_get_qdata()
|
|
* until the @object is disposed.
|
|
* Setting a previously set user data pointer, overrides (frees)
|
|
* the old pointer set, using #NULL as pointer essentially
|
|
* removes the data stored.
|
|
*
|
|
* @destroy may be specified which is called with @data as argument
|
|
* when the @object is disposed, or the data is being overwritten by
|
|
* a call to gst_mini_object_set_qdata() with the same @quark.
|
|
*/
|
|
void
|
|
gst_mini_object_set_qdata (GstMiniObject * object, GQuark quark,
|
|
gpointer data, GDestroyNotify destroy)
|
|
{
|
|
gint i;
|
|
gpointer old_data = NULL;
|
|
GDestroyNotify old_notify = NULL;
|
|
|
|
g_return_if_fail (object != NULL);
|
|
g_return_if_fail (quark > 0);
|
|
|
|
G_LOCK (qdata_mutex);
|
|
if ((i = find_notify (object, quark, FALSE, NULL, NULL)) != -1) {
|
|
|
|
old_data = QDATA_DATA (object, i);
|
|
old_notify = QDATA_DESTROY (object, i);
|
|
|
|
if (data == NULL)
|
|
remove_notify (object, i);
|
|
}
|
|
if (data != NULL)
|
|
set_notify (object, i, quark, NULL, data, destroy);
|
|
G_UNLOCK (qdata_mutex);
|
|
|
|
if (old_notify)
|
|
old_notify (old_data);
|
|
}
|
|
|
|
/**
|
|
* gst_mini_object_get_qdata:
|
|
* @object: The GstMiniObject to get a stored user data pointer from
|
|
* @quark: A #GQuark, naming the user data pointer
|
|
*
|
|
* This function gets back user data pointers stored via
|
|
* gst_mini_object_set_qdata().
|
|
*
|
|
* Returns: (transfer none): The user data pointer set, or %NULL
|
|
*/
|
|
gpointer
|
|
gst_mini_object_get_qdata (GstMiniObject * object, GQuark quark)
|
|
{
|
|
guint i;
|
|
gpointer result;
|
|
|
|
g_return_val_if_fail (object != NULL, NULL);
|
|
g_return_val_if_fail (quark > 0, NULL);
|
|
|
|
G_LOCK (qdata_mutex);
|
|
if ((i = find_notify (object, quark, FALSE, NULL, NULL)) != -1)
|
|
result = QDATA_DATA (object, i);
|
|
else
|
|
result = NULL;
|
|
G_UNLOCK (qdata_mutex);
|
|
|
|
return result;
|
|
}
|
|
|
|
/**
|
|
* gst_mini_object_steal_qdata:
|
|
* @object: The GstMiniObject to get a stored user data pointer from
|
|
* @quark: A #GQuark, naming the user data pointer
|
|
*
|
|
* This function gets back user data pointers stored via gst_mini_object_set_qdata()
|
|
* and removes the data from @object without invoking its destroy() function (if
|
|
* any was set).
|
|
*
|
|
* Returns: (transfer full): The user data pointer set, or %NULL
|
|
*/
|
|
gpointer
|
|
gst_mini_object_steal_qdata (GstMiniObject * object, GQuark quark)
|
|
{
|
|
guint i;
|
|
gpointer result;
|
|
|
|
g_return_val_if_fail (object != NULL, NULL);
|
|
g_return_val_if_fail (quark > 0, NULL);
|
|
|
|
G_LOCK (qdata_mutex);
|
|
if ((i = find_notify (object, quark, FALSE, NULL, NULL)) != -1) {
|
|
result = QDATA_DATA (object, i);
|
|
remove_notify (object, i);
|
|
} else {
|
|
result = NULL;
|
|
}
|
|
G_UNLOCK (qdata_mutex);
|
|
|
|
return result;
|
|
}
|