*
* 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.
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstminiobject
+ * @title: GstMiniObject
* @short_description: Lightweight base class for the GStreamer object hierarchy
*
* #GstMiniObject is a simple structure that can be used to implement refcounted
* object. gst_mini_object_make_writable() will return a writable version of the
* object, which might be a new copy when the refcount was not 1.
*
- * Last reviewed on 2012-03-28 (0.11.3)
+ * Opaque data can be associated with a #GstMiniObject with
+ * gst_mini_object_set_qdata() and gst_mini_object_get_qdata(). The data is
+ * meant to be specific to the particular object and is not automatically copied
+ * with gst_mini_object_copy() or similar methods.
+ *
+ * A weak reference can be added and remove with gst_mini_object_weak_ref()
+ * and gst_mini_object_weak_unref() respectively.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#include "gst/gstinfo.h"
#include <gobject/gvaluecollector.h>
-#ifndef GST_DISABLE_TRACE
-#include "gsttrace.h"
-static GstAllocTrace *_gst_mini_object_trace;
-#endif
-
/* Mutex used for weak referencing */
-G_LOCK_DEFINE_STATIC (weak_refs_mutex);
+G_LOCK_DEFINE_STATIC (qdata_mutex);
+static GQuark weak_ref_quark;
+
+#define SHARE_ONE (1 << 16)
+#define SHARE_TWO (2 << 16)
+#define SHARE_MASK (~(SHARE_ONE - 1))
+#define IS_SHARED(state) (state >= SHARE_TWO)
+#define LOCK_ONE (GST_LOCK_FLAG_LAST)
+#define FLAG_MASK (GST_LOCK_FLAG_LAST - 1)
+#define LOCK_MASK ((SHARE_ONE - 1) - FLAG_MASK)
+#define LOCK_FLAG_MASK (SHARE_ONE - 1)
+
+typedef struct
+{
+ GQuark quark;
+ GstMiniObjectNotify notify;
+ gpointer data;
+ GDestroyNotify destroy;
+} GstQData;
+
+#define QDATA(o,i) ((GstQData *)(o)->qdata)[(i)]
+#define QDATA_QUARK(o,i) (QDATA(o,i).quark)
+#define QDATA_NOTIFY(o,i) (QDATA(o,i).notify)
+#define QDATA_DATA(o,i) (QDATA(o,i).data)
+#define QDATA_DESTROY(o,i) (QDATA(o,i).destroy)
void
_priv_gst_mini_object_initialize (void)
{
-#ifndef GST_DISABLE_TRACE
- _gst_mini_object_trace = _gst_alloc_trace_register ("GstMiniObject", 0);
-#endif
+ weak_ref_quark = g_quark_from_static_string ("GstMiniObjectWeakRefQuark");
}
/**
- * gst_mini_object_init:
- * @mini_object: a #GstMiniObject
+ * gst_mini_object_init: (skip)
+ * @mini_object: a #GstMiniObject
+ * @flags: initial #GstMiniObjectFlags
* @type: the #GType of the mini-object to create
- * @size: the size of the data
- *
- * Initializes a mini-object with the desired type and size.
- *
- * MT safe
+ * @copy_func: (allow-none): the copy function, or %NULL
+ * @dispose_func: (allow-none): the dispose function, or %NULL
+ * @free_func: (allow-none): the free function or %NULL
*
- * Returns: (transfer full): the new mini-object.
+ * Initializes a mini-object with the desired type and copy/dispose/free
+ * functions.
*/
void
-gst_mini_object_init (GstMiniObject * mini_object, GType type)
+gst_mini_object_init (GstMiniObject * mini_object, guint flags, GType type,
+ GstMiniObjectCopyFunction copy_func,
+ GstMiniObjectDisposeFunction dispose_func,
+ GstMiniObjectFreeFunction free_func)
{
mini_object->type = type;
mini_object->refcount = 1;
- mini_object->flags = 0;
- mini_object->n_weak_refs = 0;
- mini_object->weak_refs = NULL;
+ mini_object->lockstate = 0;
+ mini_object->flags = flags;
-#ifndef GST_DISABLE_TRACE
- _gst_alloc_trace_new (_gst_mini_object_trace, mini_object);
-#endif
+ mini_object->copy = copy_func;
+ mini_object->dispose = dispose_func;
+ mini_object->free = free_func;
+
+ mini_object->n_qdata = 0;
+ mini_object->qdata = NULL;
+
+ GST_TRACER_MINI_OBJECT_CREATED (mini_object);
}
/**
- * gst_mini_object_copy:
+ * gst_mini_object_copy: (skip)
* @mini_object: the mini-object to copy
*
* Creates a copy of the mini-object.
}
/**
+ * gst_mini_object_lock:
+ * @object: the mini-object to lock
+ * @flags: #GstLockFlags
+ *
+ * Lock the mini-object with the specified access mode in @flags.
+ *
+ * Returns: %TRUE if @object could be locked.
+ */
+gboolean
+gst_mini_object_lock (GstMiniObject * object, GstLockFlags flags)
+{
+ gint access_mode, state, newstate;
+
+ g_return_val_if_fail (object != NULL, FALSE);
+ g_return_val_if_fail (GST_MINI_OBJECT_IS_LOCKABLE (object), FALSE);
+
+ if (G_UNLIKELY (object->flags & GST_MINI_OBJECT_FLAG_LOCK_READONLY &&
+ flags & GST_LOCK_FLAG_WRITE))
+ return FALSE;
+
+ do {
+ access_mode = flags & FLAG_MASK;
+ newstate = state = g_atomic_int_get (&object->lockstate);
+
+ GST_CAT_TRACE (GST_CAT_LOCKING, "lock %p: state %08x, access_mode %d",
+ object, state, access_mode);
+
+ if (access_mode & GST_LOCK_FLAG_EXCLUSIVE) {
+ /* shared ref */
+ newstate += SHARE_ONE;
+ access_mode &= ~GST_LOCK_FLAG_EXCLUSIVE;
+ }
+
+ /* shared counter > 1 and write access is not allowed */
+ if (((state & GST_LOCK_FLAG_WRITE) != 0
+ || (access_mode & GST_LOCK_FLAG_WRITE) != 0)
+ && IS_SHARED (newstate))
+ goto lock_failed;
+
+ if (access_mode) {
+ if ((state & LOCK_FLAG_MASK) == 0) {
+ /* nothing mapped, set access_mode */
+ newstate |= access_mode;
+ } else {
+ /* access_mode must match */
+ if ((state & access_mode) != access_mode)
+ goto lock_failed;
+ }
+ /* increase refcount */
+ newstate += LOCK_ONE;
+ }
+ } while (!g_atomic_int_compare_and_exchange (&object->lockstate, state,
+ newstate));
+
+ return TRUE;
+
+lock_failed:
+ {
+ GST_CAT_DEBUG (GST_CAT_LOCKING,
+ "lock failed %p: state %08x, access_mode %d", object, state,
+ access_mode);
+ return FALSE;
+ }
+}
+
+/**
+ * gst_mini_object_unlock:
+ * @object: the mini-object to unlock
+ * @flags: #GstLockFlags
+ *
+ * Unlock the mini-object with the specified access mode in @flags.
+ */
+void
+gst_mini_object_unlock (GstMiniObject * object, GstLockFlags flags)
+{
+ gint access_mode, state, newstate;
+
+ g_return_if_fail (object != NULL);
+ g_return_if_fail (GST_MINI_OBJECT_IS_LOCKABLE (object));
+
+ do {
+ access_mode = flags & FLAG_MASK;
+ newstate = state = g_atomic_int_get (&object->lockstate);
+
+ GST_CAT_TRACE (GST_CAT_LOCKING, "unlock %p: state %08x, access_mode %d",
+ object, state, access_mode);
+
+ if (access_mode & GST_LOCK_FLAG_EXCLUSIVE) {
+ /* shared counter */
+ g_return_if_fail (state >= SHARE_ONE);
+ newstate -= SHARE_ONE;
+ access_mode &= ~GST_LOCK_FLAG_EXCLUSIVE;
+ }
+
+ if (access_mode) {
+ g_return_if_fail ((state & access_mode) == access_mode);
+ /* decrease the refcount */
+ newstate -= LOCK_ONE;
+ /* last refcount, unset access_mode */
+ if ((newstate & LOCK_FLAG_MASK) == access_mode)
+ newstate &= ~LOCK_FLAG_MASK;
+ }
+ } while (!g_atomic_int_compare_and_exchange (&object->lockstate, state,
+ newstate));
+}
+
+/**
* gst_mini_object_is_writable:
* @mini_object: the mini-object to check
*
- * Checks if a mini-object is writable. A mini-object is writable
- * if the reference count is one. Modification of a mini-object should
- * only be done after verifying that it is writable.
+ * If @mini_object has the LOCKABLE flag set, check if the current EXCLUSIVE
+ * lock on @object is the only one, this means that changes to the object will
+ * not be visible to any other object.
*
- * MT safe
+ * If the LOCKABLE flag is not set, check if the refcount of @mini_object is
+ * exactly 1, meaning that no other reference exists to the object and that the
+ * object is therefore writable.
*
- * Returns: TRUE if the object is writable.
+ * Modification of a mini-object should only be done after verifying that it
+ * is writable.
+ *
+ * Returns: %TRUE if the object is writable.
*/
gboolean
gst_mini_object_is_writable (const GstMiniObject * mini_object)
{
+ gboolean result;
+
g_return_val_if_fail (mini_object != NULL, FALSE);
- return (GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) == 1);
+ if (GST_MINI_OBJECT_IS_LOCKABLE (mini_object)) {
+ result = !IS_SHARED (g_atomic_int_get (&mini_object->lockstate));
+ } else {
+ result = (GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) == 1);
+ }
+ return result;
}
/**
- * gst_mini_object_make_writable:
+ * gst_mini_object_make_writable: (skip)
* @mini_object: (transfer full): the mini-object to make writable
*
* Checks if a mini-object is writable. If not, a writable copy is made and
}
/**
- * gst_mini_object_ref:
+ * gst_mini_object_ref: (skip)
* @mini_object: the mini-object
*
* Increase the reference count of the mini-object.
*
- * Note that the refcount affects the writeability
+ * Note that the refcount affects the writability
* of @mini-object, see gst_mini_object_is_writable(). It is
* important to note that keeping additional references to
* GstMiniObject instances can potentially increase the number
g_return_val_if_fail (mini_object->refcount > 0, NULL);
*/
+ GST_TRACER_MINI_OBJECT_REFFED (mini_object, mini_object->refcount + 1);
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p ref %d->%d", mini_object,
GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object),
GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) + 1);
return mini_object;
}
+static gint
+find_notify (GstMiniObject * object, GQuark quark, gboolean match_notify,
+ GstMiniObjectNotify notify, gpointer data)
+{
+ guint i;
+
+ for (i = 0; i < object->n_qdata; i++) {
+ if (QDATA_QUARK (object, i) == quark) {
+ /* check if we need to match the callback too */
+ if (!match_notify || (QDATA_NOTIFY (object, i) == notify &&
+ QDATA_DATA (object, i) == data))
+ return i;
+ }
+ }
+ return -1;
+}
+
static void
-weak_refs_notify (GstMiniObject * obj)
+remove_notify (GstMiniObject * object, gint index)
+{
+ /* remove item */
+ if (--object->n_qdata == 0) {
+ /* we don't shrink but free when everything is gone */
+ g_free (object->qdata);
+ object->qdata = NULL;
+ } else if (index != object->n_qdata)
+ QDATA (object, index) = QDATA (object, object->n_qdata);
+}
+
+static void
+set_notify (GstMiniObject * object, gint index, GQuark quark,
+ GstMiniObjectNotify notify, gpointer data, GDestroyNotify destroy)
+{
+ if (index == -1) {
+ /* add item */
+ index = object->n_qdata++;
+ object->qdata =
+ g_realloc (object->qdata, sizeof (GstQData) * object->n_qdata);
+ }
+ QDATA_QUARK (object, index) = quark;
+ QDATA_NOTIFY (object, index) = notify;
+ QDATA_DATA (object, index) = data;
+ QDATA_DESTROY (object, index) = destroy;
+}
+
+static void
+call_finalize_notify (GstMiniObject * obj)
{
guint i;
- for (i = 0; i < obj->n_weak_refs; i++)
- obj->weak_refs[i].notify (obj->weak_refs[i].data, obj);
- g_free (obj->weak_refs);
+ for (i = 0; i < obj->n_qdata; i++) {
+ if (QDATA_QUARK (obj, i) == weak_ref_quark)
+ QDATA_NOTIFY (obj, i) (QDATA_DATA (obj, i), obj);
+ if (QDATA_DESTROY (obj, i))
+ QDATA_DESTROY (obj, i) (QDATA_DATA (obj, i));
+ }
}
/**
- * gst_mini_object_unref:
+ * gst_mini_object_unref: (skip)
* @mini_object: the mini-object
*
* Decreases the reference count of the mini-object, possibly freeing
if (G_UNLIKELY (g_atomic_int_dec_and_test (&mini_object->refcount))) {
gboolean do_free;
+ GST_TRACER_MINI_OBJECT_UNREFFED (mini_object, mini_object->refcount);
if (mini_object->dispose)
do_free = mini_object->dispose (mini_object);
else
/* if the subclass recycled the object (and returned FALSE) we don't
* want to free the instance anymore */
if (G_LIKELY (do_free)) {
- /* The weak reference stack is freed in the notification function */
- if (mini_object->n_weak_refs)
- weak_refs_notify (mini_object);
+ /* there should be no outstanding locks */
+ g_return_if_fail ((g_atomic_int_get (&mini_object->lockstate) & LOCK_MASK)
+ < 4);
-#ifndef GST_DISABLE_TRACE
- _gst_alloc_trace_free (_gst_mini_object_trace, mini_object);
-#endif
+ if (mini_object->n_qdata) {
+ call_finalize_notify (mini_object);
+ g_free (mini_object->qdata);
+ }
+ GST_TRACER_MINI_OBJECT_DESTROYED (mini_object);
if (mini_object->free)
mini_object->free (mini_object);
}
+ } else {
+ GST_TRACER_MINI_OBJECT_UNREFFED (mini_object, mini_object->refcount);
}
}
/**
* gst_mini_object_replace:
- * @olddata: (inout) (transfer full): pointer to a pointer to a mini-object to
- * be replaced
- * @newdata: pointer to new mini-object
+ * @olddata: (inout) (transfer full) (nullable): pointer to a pointer to a
+ * mini-object to be replaced
+ * @newdata: (allow-none): pointer to new mini-object
*
* Atomically modifies a pointer to point to a new mini-object.
* The reference count of @olddata is decreased and the reference count of
* @newdata is increased.
*
- * Either @newdata and the value pointed to by @olddata may be NULL.
+ * Either @newdata and the value pointed to by @olddata may be %NULL.
*
- * Returns: TRUE if @newdata was different from @olddata
+ * Returns: %TRUE if @newdata was different from @olddata
*/
gboolean
gst_mini_object_replace (GstMiniObject ** olddata, GstMiniObject * newdata)
}
/**
- * gst_mini_object_steal:
+ * gst_mini_object_steal: (skip)
* @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
+ * Replace the current #GstMiniObject pointer to by @olddata with %NULL and
* return the old value.
*
* Returns: the #GstMiniObject at @oldata
* 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.
+ * Either @newdata and the value pointed to by @olddata may be %NULL.
*
- * Returns: TRUE if @newdata was different from @olddata
+ * Returns: %TRUE if @newdata was different from @olddata
*/
gboolean
gst_mini_object_take (GstMiniObject ** olddata, GstMiniObject * newdata)
* 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,
- GstMiniObjectWeakNotify notify, gpointer data)
+ GstMiniObjectNotify notify, gpointer data)
{
- guint i;
-
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 (weak_refs_mutex);
-
- if (object->n_weak_refs) {
- /* Don't add the weak reference if it already exists. */
- for (i = 0; i < object->n_weak_refs; i++) {
- if (object->weak_refs[i].notify == notify &&
- object->weak_refs[i].data == data) {
- g_warning ("%s: Attempt to re-add existing weak ref %p(%p) failed.",
- G_STRFUNC, notify, data);
- goto found;
- }
- }
-
- i = object->n_weak_refs++;
- object->weak_refs =
- g_realloc (object->weak_refs, sizeof (object->weak_refs[0]) * i);
- } else {
- object->weak_refs = g_malloc0 (sizeof (object->weak_refs[0]));
- object->n_weak_refs = 1;
- i = 0;
- }
- object->weak_refs[i].notify = notify;
- object->weak_refs[i].data = data;
-found:
- G_UNLOCK (weak_refs_mutex);
+ G_LOCK (qdata_mutex);
+ set_notify (object, -1, weak_ref_quark, notify, data, NULL);
+ G_UNLOCK (qdata_mutex);
}
/**
* @notify: callback to search for
* @data: data to search for
*
- * Removes a weak reference callback to a mini object.
- *
- * Since: 0.10.35
+ * Removes a weak reference callback from a mini object.
*/
void
gst_mini_object_weak_unref (GstMiniObject * object,
- GstMiniObjectWeakNotify notify, gpointer data)
+ GstMiniObjectNotify notify, gpointer data)
{
- gboolean found_one = FALSE;
+ gint i;
g_return_if_fail (object != NULL);
g_return_if_fail (notify != NULL);
- G_LOCK (weak_refs_mutex);
+ 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 (object:%p data:%p)", G_STRFUNC,
+ notify, object, data);
+ }
+ G_UNLOCK (qdata_mutex);
+}
- if (object->n_weak_refs) {
- guint i;
+/**
+ * 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 (retrieved 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);
- for (i = 0; i < object->n_weak_refs; i++)
- if (object->weak_refs[i].notify == notify &&
- object->weak_refs[i].data == data) {
- found_one = TRUE;
- object->n_weak_refs -= 1;
- if (i != object->n_weak_refs)
- object->weak_refs[i] = object->weak_refs[object->n_weak_refs];
+ G_LOCK (qdata_mutex);
+ if ((i = find_notify (object, quark, FALSE, NULL, NULL)) != -1) {
- break;
- }
+ old_data = QDATA_DATA (object, i);
+ old_notify = QDATA_DESTROY (object, i);
+
+ if (data == NULL)
+ remove_notify (object, i);
}
- G_UNLOCK (weak_refs_mutex);
- if (!found_one)
- g_warning ("%s: couldn't find weak ref %p(%p)", G_STRFUNC, notify, data);
+ 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) (nullable): 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) (nullable): 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;
}
projects / platform / upstream / gstreamer.git / blobdiff