*
* 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
* A copy can be made with gst_mini_object_copy().
*
* gst_mini_object_is_writable() will return %TRUE when the refcount of the
- * object is exactly 1, meaning the current caller has the only reference to the
- * 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.
+ * object is exactly 1 and there is no parent or a single parent exists and is
+ * writable itself, meaning the current caller has the only reference to the
+ * 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)
+
+/* For backwards compatibility reasons we use the
+ * guint and gpointer in the GstMiniObject struct in
+ * a rather complicated way to store the parent(s) and qdata.
+ * Originally the were just the number of qdatas and the qdata.
+ *
+ * The guint is used as an atomic state integer with the following
+ * states:
+ * - Locked: 0, basically a spinlock
+ * - No parent, no qdata: 1 (pointer is NULL)
+ * - One parent: 2 (pointer contains the parent)
+ * - Multiple parents or qdata: 3 (pointer contains a PrivData struct)
+ *
+ * Unless we're in state 3, we always have to move to Locking state
+ * atomically and release that again later to the target state whenever
+ * accessing the pointer. When we're in state 3, we will never move to lower
+ * states again
+ *
+ * FIXME 2.0: We should store this directly inside the struct, possibly
+ * keeping space directly allocated for a couple of parents
+ */
+
+enum
+{
+ PRIV_DATA_STATE_LOCKED = 0,
+ PRIV_DATA_STATE_NO_PARENT = 1,
+ PRIV_DATA_STATE_ONE_PARENT = 2,
+ PRIV_DATA_STATE_PARENTS_OR_QDATA = 3,
+};
+
+typedef struct
+{
+ GQuark quark;
+ GstMiniObjectNotify notify;
+ gpointer data;
+ GDestroyNotify destroy;
+} GstQData;
+
+typedef struct
+{
+ /* Atomic spinlock: 1 if locked, 0 otherwise */
+ gint parent_lock;
+ guint n_parents, n_parents_len;
+ GstMiniObject **parents;
+
+ guint n_qdata, n_qdata_len;
+ GstQData *qdata;
+} PrivData;
+
+#define QDATA(q,i) (q->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, gsize size)
+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->size = size;
- 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;
+
+ g_atomic_int_set ((gint *) & mini_object->priv_uint,
+ PRIV_DATA_STATE_NO_PARENT);
+ mini_object->priv_pointer = 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.
*
* MT safe
*
- * Returns: (transfer full): the new mini-object.
+ * Returns: (transfer full) (nullable): the new mini-object if copying is
+ * possible, %NULL otherwise.
*/
GstMiniObject *
gst_mini_object_copy (const GstMiniObject * 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));
+}
+
+/* Locks the priv pointer and sets the priv uint to PRIV_DATA_STATE_LOCKED,
+ * unless the full struct was already stored in the priv pointer.
+ *
+ * Returns the previous state of the priv uint
+ */
+static guint
+lock_priv_pointer (GstMiniObject * object)
+{
+ gint priv_state = g_atomic_int_get ((gint *) & object->priv_uint);
+
+ if (priv_state != PRIV_DATA_STATE_PARENTS_OR_QDATA) {
+ /* As long as the struct was not allocated yet and either someone else
+ * locked it or our priv_state is out of date, try to lock it */
+ while (priv_state != PRIV_DATA_STATE_PARENTS_OR_QDATA &&
+ (priv_state == PRIV_DATA_STATE_LOCKED ||
+ !g_atomic_int_compare_and_exchange ((gint *) & object->priv_uint,
+ priv_state, PRIV_DATA_STATE_LOCKED)))
+ priv_state = g_atomic_int_get ((gint *) & object->priv_uint);
+
+ /* Note that if we got the full struct, we did not store
+ * PRIV_DATA_STATE_LOCKED and did not actually lock the priv pointer */
+ }
+
+ return priv_state;
+}
+
+/**
* 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.
+ *
+ * Modification of a mini-object should only be done after verifying that it
+ * is writable.
*
- * Returns: TRUE if the object is writable.
+ * Returns: %TRUE if the object is writable.
*/
gboolean
gst_mini_object_is_writable (const GstMiniObject * mini_object)
{
+ gboolean result;
+ gint priv_state;
+
g_return_val_if_fail (mini_object != NULL, FALSE);
- return (GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) == 1);
+ /* Let's first check our own writability. If this already fails there's
+ * no point in checking anything else */
+ 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);
+ }
+ if (!result)
+ return result;
+
+ /* We are writable ourselves, but are there parents and are they all
+ * writable too? */
+ priv_state = lock_priv_pointer (GST_MINI_OBJECT_CAST (mini_object));
+
+ /* Now we either have to check the full struct and all the
+ * parents in there, or if there is exactly one parent we
+ * can check that one */
+ if (priv_state == PRIV_DATA_STATE_PARENTS_OR_QDATA) {
+ PrivData *priv_data = mini_object->priv_pointer;
+
+ /* Lock parents */
+ while (!g_atomic_int_compare_and_exchange (&priv_data->parent_lock, 0, 1));
+
+ /* If we have one parent, we're only writable if that parent is writable.
+ * Otherwise if we have multiple parents we are not writable, and if
+ * we have no parent, we are writable */
+ if (priv_data->n_parents == 1)
+ result = gst_mini_object_is_writable (priv_data->parents[0]);
+ else if (priv_data->n_parents == 0)
+ result = TRUE;
+ else
+ result = FALSE;
+
+ /* Unlock again */
+ g_atomic_int_set (&priv_data->parent_lock, 0);
+ } else {
+ if (priv_state == PRIV_DATA_STATE_ONE_PARENT) {
+ result = gst_mini_object_is_writable (mini_object->priv_pointer);
+ } else {
+ g_assert (priv_state == PRIV_DATA_STATE_NO_PARENT);
+ result = TRUE;
+ }
+
+ /* Unlock again */
+ g_atomic_int_set ((gint *) & mini_object->priv_uint, priv_state);
+ }
+
+ 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
GstMiniObject *
gst_mini_object_ref (GstMiniObject * mini_object)
{
+ gint old_refcount, new_refcount;
+
g_return_val_if_fail (mini_object != NULL, NULL);
/* we can't assert that the refcount > 0 since the _free functions
- * increments the refcount from 0 to 1 again to allow resurecting
+ * increments the refcount from 0 to 1 again to allow resurrecting
* the object
g_return_val_if_fail (mini_object->refcount > 0, NULL);
*/
+ old_refcount = g_atomic_int_add (&mini_object->refcount, 1);
+ new_refcount = old_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);
+ old_refcount, new_refcount);
- g_atomic_int_inc (&mini_object->refcount);
+ GST_TRACER_MINI_OBJECT_REFFED (mini_object, new_refcount);
return mini_object;
}
+/* Called with global qdata lock */
+static gint
+find_notify (GstMiniObject * object, GQuark quark, gboolean match_notify,
+ GstMiniObjectNotify notify, gpointer data)
+{
+ guint i;
+ gint priv_state = g_atomic_int_get ((gint *) & object->priv_uint);
+ PrivData *priv_data;
+
+ if (priv_state != PRIV_DATA_STATE_PARENTS_OR_QDATA)
+ return -1;
+
+ priv_data = object->priv_pointer;
+
+ for (i = 0; i < priv_data->n_qdata; i++) {
+ if (QDATA_QUARK (priv_data, i) == quark) {
+ /* check if we need to match the callback too */
+ if (!match_notify || (QDATA_NOTIFY (priv_data, i) == notify &&
+ QDATA_DATA (priv_data, i) == data))
+ return i;
+ }
+ }
+ return -1;
+}
+
+static void
+remove_notify (GstMiniObject * object, gint index)
+{
+ gint priv_state = g_atomic_int_get ((gint *) & object->priv_uint);
+ PrivData *priv_data;
+
+ g_assert (priv_state == PRIV_DATA_STATE_PARENTS_OR_QDATA);
+ priv_data = object->priv_pointer;
+
+ /* remove item */
+ priv_data->n_qdata--;
+ if (priv_data->n_qdata == 0) {
+ /* we don't shrink but free when everything is gone */
+ g_free (priv_data->qdata);
+ priv_data->qdata = NULL;
+ priv_data->n_qdata_len = 0;
+ } else if (index != priv_data->n_qdata) {
+ QDATA (priv_data, index) = QDATA (priv_data, priv_data->n_qdata);
+ }
+}
+
+/* Make sure we allocate the PrivData of this object if not happened yet */
+static void
+ensure_priv_data (GstMiniObject * object)
+{
+ gint priv_state;
+ PrivData *priv_data;
+ GstMiniObject *parent = NULL;
+
+ GST_CAT_DEBUG (GST_CAT_PERFORMANCE,
+ "allocating private data %s miniobject %p",
+ g_type_name (GST_MINI_OBJECT_TYPE (object)), object);
+
+ priv_state = lock_priv_pointer (object);
+ if (priv_state == PRIV_DATA_STATE_PARENTS_OR_QDATA)
+ return;
+
+ /* Now we're either locked, or someone has already allocated the struct
+ * before us and we can just go ahead
+ *
+ * Note: if someone else allocated it in the meantime, we don't have to
+ * unlock as we didn't lock! */
+ if (priv_state != PRIV_DATA_STATE_PARENTS_OR_QDATA) {
+ if (priv_state == PRIV_DATA_STATE_ONE_PARENT)
+ parent = object->priv_pointer;
+
+ object->priv_pointer = priv_data = g_new0 (PrivData, 1);
+
+ if (parent) {
+ priv_data->parents = g_new (GstMiniObject *, 16);
+ priv_data->n_parents_len = 16;
+ priv_data->n_parents = 1;
+ priv_data->parents[0] = parent;
+ }
+
+ /* Unlock */
+ g_atomic_int_set ((gint *) & object->priv_uint,
+ PRIV_DATA_STATE_PARENTS_OR_QDATA);
+ }
+}
+
+static void
+set_notify (GstMiniObject * object, gint index, GQuark quark,
+ GstMiniObjectNotify notify, gpointer data, GDestroyNotify destroy)
+{
+ PrivData *priv_data;
+
+ ensure_priv_data (object);
+ priv_data = object->priv_pointer;
+
+ if (index == -1) {
+ /* add item */
+ index = priv_data->n_qdata++;
+ if (index >= priv_data->n_qdata_len) {
+ priv_data->n_qdata_len *= 2;
+ if (priv_data->n_qdata_len == 0)
+ priv_data->n_qdata_len = 16;
+
+ priv_data->qdata =
+ g_realloc (priv_data->qdata,
+ sizeof (GstQData) * priv_data->n_qdata_len);
+ }
+ }
+
+ QDATA_QUARK (priv_data, index) = quark;
+ QDATA_NOTIFY (priv_data, index) = notify;
+ QDATA_DATA (priv_data, index) = data;
+ QDATA_DESTROY (priv_data, index) = destroy;
+}
+
static void
-weak_refs_notify (GstMiniObject * obj)
+free_priv_data (GstMiniObject * obj)
{
guint i;
+ gint priv_state = g_atomic_int_get ((gint *) & obj->priv_uint);
+ PrivData *priv_data;
+
+ if (priv_state != PRIV_DATA_STATE_PARENTS_OR_QDATA) {
+ if (priv_state == PRIV_DATA_STATE_LOCKED) {
+ g_warning
+ ("%s: object finalizing but has locked private data (object:%p)",
+ G_STRFUNC, obj);
+ } else if (priv_state == PRIV_DATA_STATE_ONE_PARENT) {
+ g_warning
+ ("%s: object finalizing but still has parent (object:%p, parent:%p)",
+ G_STRFUNC, obj, obj->priv_pointer);
+ }
+
+ return;
+ }
- 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);
+ priv_data = obj->priv_pointer;
+
+ for (i = 0; i < priv_data->n_qdata; i++) {
+ if (QDATA_QUARK (priv_data, i) == weak_ref_quark)
+ QDATA_NOTIFY (priv_data, i) (QDATA_DATA (priv_data, i), obj);
+ if (QDATA_DESTROY (priv_data, i))
+ QDATA_DESTROY (priv_data, i) (QDATA_DATA (priv_data, i));
+ }
+ g_free (priv_data->qdata);
+
+ if (priv_data->n_parents)
+ g_warning ("%s: object finalizing but still has %d parents (object:%p)",
+ G_STRFUNC, priv_data->n_parents, obj);
+ g_free (priv_data->parents);
+
+ g_free (priv_data);
}
/**
- * gst_mini_object_unref:
+ * gst_mini_object_unref: (skip)
* @mini_object: the mini-object
*
* Decreases the reference count of the mini-object, possibly freeing
void
gst_mini_object_unref (GstMiniObject * mini_object)
{
+ gint old_refcount, new_refcount;
+
g_return_if_fail (mini_object != NULL);
+ g_return_if_fail (GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) > 0);
+
+ old_refcount = g_atomic_int_add (&mini_object->refcount, -1);
+ new_refcount = old_refcount - 1;
+
+ g_return_if_fail (old_refcount > 0);
GST_CAT_TRACE (GST_CAT_REFCOUNTING, "%p unref %d->%d",
- mini_object,
- GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object),
- GST_MINI_OBJECT_REFCOUNT_VALUE (mini_object) - 1);
+ mini_object, old_refcount, new_refcount);
- g_return_if_fail (mini_object->refcount > 0);
+ GST_TRACER_MINI_OBJECT_UNREFFED (mini_object, new_refcount);
- if (G_UNLIKELY (g_atomic_int_dec_and_test (&mini_object->refcount))) {
+ if (new_refcount == 0) {
gboolean do_free;
if (mini_object->dispose)
/* 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
+ free_priv_data (mini_object);
+
+ GST_TRACER_MINI_OBJECT_DESTROYED (mini_object);
if (mini_object->free)
mini_object->free (mini_object);
}
}
/**
+ * gst_clear_mini_object: (skip)
+ * @object_ptr: a pointer to a #GstMiniObject reference
+ *
+ * Clears a reference to a #GstMiniObject.
+ *
+ * @object_ptr must not be %NULL.
+ *
+ * If the reference is %NULL then this function does nothing.
+ * Otherwise, the reference count of the object is decreased using
+ * gst_mini_object_unref() and the pointer is set to %NULL.
+ *
+ * A macro is also included that allows this function to be used without
+ * pointer casts.
+ *
+ * Since: 1.16
+ **/
+#undef gst_clear_mini_object
+void
+gst_clear_mini_object (GstMiniObject ** object_ptr)
+{
+ g_clear_pointer (object_ptr, gst_mini_object_unref);
+}
+
+/**
* 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
+ * Returns: (nullable): the #GstMiniObject at @oldata
*/
GstMiniObject *
gst_mini_object_steal (GstMiniObject ** olddata)
* 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) {
+/**
+ * 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);
+
+ G_LOCK (qdata_mutex);
+ if ((i = find_notify (object, quark, FALSE, NULL, NULL)) != -1) {
+ PrivData *priv_data = object->priv_pointer;
+
+ old_data = QDATA_DATA (priv_data, i);
+ old_notify = QDATA_DESTROY (priv_data, 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) (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) {
+ PrivData *priv_data = object->priv_pointer;
+ result = QDATA_DATA (priv_data, 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) {
+ PrivData *priv_data = object->priv_pointer;
+ result = QDATA_DATA (priv_data, i);
+ remove_notify (object, i);
+ } else {
+ result = NULL;
+ }
+ G_UNLOCK (qdata_mutex);
+
+ return result;
+}
+
+/**
+ * gst_mini_object_add_parent:
+ * @object: a #GstMiniObject
+ * @parent: a parent #GstMiniObject
+ *
+ * This adds @parent as a parent for @object. Having one ore more parents affects the
+ * writability of @object: if a @parent is not writable, @object is also not
+ * writable, regardless of its refcount. @object is only writable if all
+ * the parents are writable and its own refcount is exactly 1.
+ *
+ * Note: This function does not take ownership of @parent and also does not
+ * take an additional reference. It is the responsibility of the caller to
+ * remove the parent again at a later time.
+ *
+ * Since: 1.16
+ */
+void
+gst_mini_object_add_parent (GstMiniObject * object, GstMiniObject * parent)
+{
+ gint priv_state;
+
+ g_return_if_fail (object != NULL);
+
+ GST_CAT_TRACE (GST_CAT_REFCOUNTING, "adding parent %p to object %p", parent,
+ object);
+
+ priv_state = lock_priv_pointer (object);
+ /* If we already had one parent, we need to allocate the full struct now */
+ if (priv_state == PRIV_DATA_STATE_ONE_PARENT) {
+ /* Unlock again */
+ g_atomic_int_set ((gint *) & object->priv_uint, priv_state);
+
+ ensure_priv_data (object);
+ priv_state = PRIV_DATA_STATE_PARENTS_OR_QDATA;
+ }
+
+ /* Now we either have to add the new parent to the full struct, or add
+ * our one and only parent to the pointer field */
+ if (priv_state == PRIV_DATA_STATE_PARENTS_OR_QDATA) {
+ PrivData *priv_data = object->priv_pointer;
+
+ /* Lock parents */
+ while (!g_atomic_int_compare_and_exchange (&priv_data->parent_lock, 0, 1));
+
+ if (priv_data->n_parents >= priv_data->n_parents_len) {
+ priv_data->n_parents_len *= 2;
+ if (priv_data->n_parents_len == 0)
+ priv_data->n_parents_len = 16;
+
+ priv_data->parents =
+ g_realloc (priv_data->parents,
+ priv_data->n_parents_len * sizeof (GstMiniObject *));
+ }
+ priv_data->parents[priv_data->n_parents] = parent;
+ priv_data->n_parents++;
+
+ /* Unlock again */
+ g_atomic_int_set (&priv_data->parent_lock, 0);
+ } else if (priv_state == PRIV_DATA_STATE_NO_PARENT) {
+ object->priv_pointer = parent;
+
+ /* Unlock again */
+ g_atomic_int_set ((gint *) & object->priv_uint, PRIV_DATA_STATE_ONE_PARENT);
+ } else {
+ g_assert_not_reached ();
+ }
+}
+
+/**
+ * gst_mini_object_remove_parent:
+ * @object: a #GstMiniObject
+ * @parent: a parent #GstMiniObject
+ *
+ * This removes @parent as a parent for @object. See
+ * gst_mini_object_add_parent().
+ *
+ * Since: 1.16
+ */
+void
+gst_mini_object_remove_parent (GstMiniObject * object, GstMiniObject * parent)
+{
+ gint priv_state;
+
+ g_return_if_fail (object != NULL);
+
+ GST_CAT_TRACE (GST_CAT_REFCOUNTING, "removing parent %p from object %p",
+ parent, object);
+
+ priv_state = lock_priv_pointer (object);
+
+ /* Now we either have to add the new parent to the full struct, or add
+ * our one and only parent to the pointer field */
+ if (priv_state == PRIV_DATA_STATE_PARENTS_OR_QDATA) {
+ PrivData *priv_data = object->priv_pointer;
guint i;
- 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];
+ /* Lock parents */
+ while (!g_atomic_int_compare_and_exchange (&priv_data->parent_lock, 0, 1));
+ for (i = 0; i < priv_data->n_parents; i++)
+ if (parent == priv_data->parents[i])
break;
- }
+
+ if (i != priv_data->n_parents) {
+ priv_data->n_parents--;
+ if (priv_data->n_parents != i)
+ priv_data->parents[i] = priv_data->parents[priv_data->n_parents];
+ } else {
+ g_warning ("%s: couldn't find parent %p (object:%p)", G_STRFUNC,
+ object, parent);
+ }
+
+ /* Unlock again */
+ g_atomic_int_set (&priv_data->parent_lock, 0);
+ } else if (priv_state == PRIV_DATA_STATE_ONE_PARENT) {
+ if (object->priv_pointer != parent) {
+ g_warning ("%s: couldn't find parent %p (object:%p)", G_STRFUNC,
+ object, parent);
+ /* Unlock again */
+ g_atomic_int_set ((gint *) & object->priv_uint, priv_state);
+ } else {
+ object->priv_pointer = NULL;
+ /* Unlock again */
+ g_atomic_int_set ((gint *) & object->priv_uint,
+ PRIV_DATA_STATE_NO_PARENT);
+ }
+ } else {
+ /* Unlock again */
+ g_atomic_int_set ((gint *) & object->priv_uint, PRIV_DATA_STATE_NO_PARENT);
}
- G_UNLOCK (weak_refs_mutex);
- if (!found_one)
- g_warning ("%s: couldn't find weak ref %p(%p)", G_STRFUNC, notify, data);
}
projects / platform / upstream / gstreamer.git / blobdiff