gstreamer/libs/gst/base/gstdataqueue.c
Thiago Santos 1681a1b1e0 dataqueue: add gst_data_queue_peek
This function works just like gst_data_queue_pop, but it doesn't
remove the object from the queue.

Useful when inspecting multiple GstDataQueues to decide from which
to pop the element from.

Add: gst_data_queue_peek
2013-04-18 14:45:47 -03:00

752 lines
22 KiB
C

/* GStreamer
* Copyright (C) 2006 Edward Hervey <edward@fluendo.com>
*
* gstdataqueue.c:
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstdataqueue
* @short_description: Threadsafe queueing object
*
* #GstDataQueue is an object that handles threadsafe queueing of objects. It
* also provides size-related functionality. This object should be used for
* any #GstElement that wishes to provide some sort of queueing functionality.
*/
#include <gst/gst.h>
#include "string.h"
#include "gstdataqueue.h"
#include "gstqueuearray.h"
#include "gst/glib-compat-private.h"
GST_DEBUG_CATEGORY_STATIC (data_queue_debug);
#define GST_CAT_DEFAULT (data_queue_debug)
GST_DEBUG_CATEGORY_STATIC (data_queue_dataflow);
/* Queue signals and args */
enum
{
SIGNAL_EMPTY,
SIGNAL_FULL,
LAST_SIGNAL
};
enum
{
PROP_0,
PROP_CUR_LEVEL_VISIBLE,
PROP_CUR_LEVEL_BYTES,
PROP_CUR_LEVEL_TIME
/* FILL ME */
};
struct _GstDataQueuePrivate
{
/* the array of data we're keeping our grubby hands on */
GstQueueArray *queue;
GstDataQueueSize cur_level; /* size of the queue */
GstDataQueueCheckFullFunction checkfull; /* Callback to check if the queue is full */
gpointer *checkdata;
GMutex qlock; /* lock for queue (vs object lock) */
gboolean waiting_add;
GCond item_add; /* signals buffers now available for reading */
gboolean waiting_del;
GCond item_del; /* signals space now available for writing */
gboolean flushing; /* indicates whether conditions where signalled because
* of external flushing */
GstDataQueueFullCallback fullcallback;
GstDataQueueEmptyCallback emptycallback;
};
#define GST_DATA_QUEUE_MUTEX_LOCK(q) G_STMT_START { \
GST_CAT_TRACE (data_queue_dataflow, \
"locking qlock from thread %p", \
g_thread_self ()); \
g_mutex_lock (&q->priv->qlock); \
GST_CAT_TRACE (data_queue_dataflow, \
"locked qlock from thread %p", \
g_thread_self ()); \
} G_STMT_END
#define GST_DATA_QUEUE_MUTEX_LOCK_CHECK(q, label) G_STMT_START { \
GST_DATA_QUEUE_MUTEX_LOCK (q); \
if (q->priv->flushing) \
goto label; \
} G_STMT_END
#define GST_DATA_QUEUE_MUTEX_UNLOCK(q) G_STMT_START { \
GST_CAT_TRACE (data_queue_dataflow, \
"unlocking qlock from thread %p", \
g_thread_self ()); \
g_mutex_unlock (&q->priv->qlock); \
} G_STMT_END
#define STATUS(q, msg) \
GST_CAT_LOG (data_queue_dataflow, \
"queue:%p " msg ": %u visible items, %u " \
"bytes, %"G_GUINT64_FORMAT \
" ns, %u elements", \
queue, \
q->priv->cur_level.visible, \
q->priv->cur_level.bytes, \
q->priv->cur_level.time, \
gst_queue_array_get_length (q->priv->queue))
static void gst_data_queue_finalize (GObject * object);
static void gst_data_queue_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec);
static void gst_data_queue_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec);
static guint gst_data_queue_signals[LAST_SIGNAL] = { 0 };
#define _do_init \
{ \
GST_DEBUG_CATEGORY_INIT (data_queue_debug, "dataqueue", 0, \
"data queue object"); \
GST_DEBUG_CATEGORY_INIT (data_queue_dataflow, "data_queue_dataflow", 0, \
"dataflow inside the data queue object"); \
}
#define parent_class gst_data_queue_parent_class
G_DEFINE_TYPE_WITH_CODE (GstDataQueue, gst_data_queue, G_TYPE_OBJECT, _do_init);
static void
gst_data_queue_class_init (GstDataQueueClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
g_type_class_add_private (klass, sizeof (GstDataQueuePrivate));
gobject_class->set_property = gst_data_queue_set_property;
gobject_class->get_property = gst_data_queue_get_property;
/* signals */
/**
* GstDataQueue::empty:
* @queue: the queue instance
*
* Reports that the queue became empty (empty).
* A queue is empty if the total amount of visible items inside it (num-visible, time,
* size) is lower than the boundary values which can be set through the GObject
* properties.
*/
gst_data_queue_signals[SIGNAL_EMPTY] =
g_signal_new ("empty", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (GstDataQueueClass, empty), NULL, NULL,
g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);
/**
* GstDataQueue::full:
* @queue: the queue instance
*
* Reports that the queue became full (full).
* A queue is full if the total amount of data inside it (num-visible, time,
* size) is higher than the boundary values which can be set through the GObject
* properties.
*/
gst_data_queue_signals[SIGNAL_FULL] =
g_signal_new ("full", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_FIRST,
G_STRUCT_OFFSET (GstDataQueueClass, full), NULL, NULL,
g_cclosure_marshal_VOID__VOID, G_TYPE_NONE, 0);
/* properties */
g_object_class_install_property (gobject_class, PROP_CUR_LEVEL_BYTES,
g_param_spec_uint ("current-level-bytes", "Current level (kB)",
"Current amount of data in the queue (bytes)",
0, G_MAXUINT, 0, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_CUR_LEVEL_VISIBLE,
g_param_spec_uint ("current-level-visible",
"Current level (visible items)",
"Current number of visible items in the queue", 0, G_MAXUINT, 0,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_CUR_LEVEL_TIME,
g_param_spec_uint64 ("current-level-time", "Current level (ns)",
"Current amount of data in the queue (in ns)", 0, G_MAXUINT64, 0,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
gobject_class->finalize = gst_data_queue_finalize;
}
static void
gst_data_queue_init (GstDataQueue * queue)
{
queue->priv =
G_TYPE_INSTANCE_GET_PRIVATE (queue, GST_TYPE_DATA_QUEUE,
GstDataQueuePrivate);
queue->priv->cur_level.visible = 0; /* no content */
queue->priv->cur_level.bytes = 0; /* no content */
queue->priv->cur_level.time = 0; /* no content */
queue->priv->checkfull = NULL;
g_mutex_init (&queue->priv->qlock);
g_cond_init (&queue->priv->item_add);
g_cond_init (&queue->priv->item_del);
queue->priv->queue = gst_queue_array_new (50);
GST_DEBUG ("initialized queue's not_empty & not_full conditions");
}
/**
* gst_data_queue_new:
* @checkfull: the callback used to tell if the element considers the queue full
* or not.
* @fullcallback: the callback which will be called when the queue is considered full.
* @emptycallback: the callback which will be called when the queue is considered empty.
* @checkdata: a #gpointer that will be given in the @checkfull callback.
*
* Creates a new #GstDataQueue. The difference with @gst_data_queue_new is that it will
* not emit the 'full' and 'empty' signals, but instead calling directly @fullcallback
* or @emptycallback.
*
* Returns: a new #GstDataQueue.
*
* Since: 1.2.0
*/
GstDataQueue *
gst_data_queue_new (GstDataQueueCheckFullFunction checkfull,
GstDataQueueFullCallback fullcallback,
GstDataQueueEmptyCallback emptycallback, gpointer checkdata)
{
GstDataQueue *ret;
g_return_val_if_fail (checkfull != NULL, NULL);
ret = g_object_newv (GST_TYPE_DATA_QUEUE, 0, NULL);
ret->priv->checkfull = checkfull;
ret->priv->checkdata = checkdata;
ret->priv->fullcallback = fullcallback;
ret->priv->emptycallback = emptycallback;
return ret;
}
static void
gst_data_queue_cleanup (GstDataQueue * queue)
{
GstDataQueuePrivate *priv = queue->priv;
while (!gst_queue_array_is_empty (priv->queue)) {
GstDataQueueItem *item = gst_queue_array_pop_head (priv->queue);
/* Just call the destroy notify on the item */
item->destroy (item);
}
priv->cur_level.visible = 0;
priv->cur_level.bytes = 0;
priv->cur_level.time = 0;
}
/* called only once, as opposed to dispose */
static void
gst_data_queue_finalize (GObject * object)
{
GstDataQueue *queue = GST_DATA_QUEUE (object);
GstDataQueuePrivate *priv = queue->priv;
GST_DEBUG ("finalizing queue");
gst_data_queue_cleanup (queue);
gst_queue_array_free (priv->queue);
GST_DEBUG ("free mutex");
g_mutex_clear (&priv->qlock);
GST_DEBUG ("done free mutex");
g_cond_clear (&priv->item_add);
g_cond_clear (&priv->item_del);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
static inline void
gst_data_queue_locked_flush (GstDataQueue * queue)
{
GstDataQueuePrivate *priv = queue->priv;
STATUS (queue, "before flushing");
gst_data_queue_cleanup (queue);
STATUS (queue, "after flushing");
/* we deleted something... */
if (priv->waiting_del)
g_cond_signal (&priv->item_del);
}
static inline gboolean
gst_data_queue_locked_is_empty (GstDataQueue * queue)
{
GstDataQueuePrivate *priv = queue->priv;
return (gst_queue_array_get_length (priv->queue) == 0);
}
static inline gboolean
gst_data_queue_locked_is_full (GstDataQueue * queue)
{
GstDataQueuePrivate *priv = queue->priv;
return priv->checkfull (queue, priv->cur_level.visible,
priv->cur_level.bytes, priv->cur_level.time, priv->checkdata);
}
/**
* gst_data_queue_flush:
* @queue: a #GstDataQueue.
*
* Flushes all the contents of the @queue. Any call to #gst_data_queue_push and
* #gst_data_queue_pop will be released.
* MT safe.
*
* Since: 1.2.0
*/
void
gst_data_queue_flush (GstDataQueue * queue)
{
GST_DEBUG ("queue:%p", queue);
GST_DATA_QUEUE_MUTEX_LOCK (queue);
gst_data_queue_locked_flush (queue);
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
}
/**
* gst_data_queue_is_empty:
* @queue: a #GstDataQueue.
*
* Queries if there are any items in the @queue.
* MT safe.
*
* Returns: #TRUE if @queue is empty.
*
* Since: 1.2.0
*/
gboolean
gst_data_queue_is_empty (GstDataQueue * queue)
{
gboolean res;
GST_DATA_QUEUE_MUTEX_LOCK (queue);
res = gst_data_queue_locked_is_empty (queue);
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
return res;
}
/**
* gst_data_queue_is_full:
* @queue: a #GstDataQueue.
*
* Queries if @queue is full. This check will be done using the
* #GstDataQueueCheckFullFunction registered with @queue.
* MT safe.
*
* Returns: #TRUE if @queue is full.
*
* Since: 1.2.0
*/
gboolean
gst_data_queue_is_full (GstDataQueue * queue)
{
gboolean res;
GST_DATA_QUEUE_MUTEX_LOCK (queue);
res = gst_data_queue_locked_is_full (queue);
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
return res;
}
/**
* gst_data_queue_set_flushing:
* @queue: a #GstDataQueue.
* @flushing: a #gboolean stating if the queue will be flushing or not.
*
* Sets the queue to flushing state if @flushing is #TRUE. If set to flushing
* state, any incoming data on the @queue will be discarded. Any call currently
* blocking on #gst_data_queue_push or #gst_data_queue_pop will return straight
* away with a return value of #FALSE. While the @queue is in flushing state,
* all calls to those two functions will return #FALSE.
*
* MT Safe.
*
* Since: 1.2.0
*/
void
gst_data_queue_set_flushing (GstDataQueue * queue, gboolean flushing)
{
GstDataQueuePrivate *priv = queue->priv;
GST_DEBUG ("queue:%p , flushing:%d", queue, flushing);
GST_DATA_QUEUE_MUTEX_LOCK (queue);
priv->flushing = flushing;
if (flushing) {
/* release push/pop functions */
if (priv->waiting_add)
g_cond_signal (&priv->item_add);
if (priv->waiting_del)
g_cond_signal (&priv->item_del);
}
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
}
/**
* gst_data_queue_push:
* @queue: a #GstDataQueue.
* @item: a #GstDataQueueItem.
*
* Pushes a #GstDataQueueItem (or a structure that begins with the same fields)
* on the @queue. If the @queue is full, the call will block until space is
* available, OR the @queue is set to flushing state.
* MT safe.
*
* Note that this function has slightly different semantics than gst_pad_push()
* and gst_pad_push_event(): this function only takes ownership of @item and
* the #GstMiniObject contained in @item if the push was successful. If FALSE
* is returned, the caller is responsible for freeing @item and its contents.
*
* Returns: #TRUE if the @item was successfully pushed on the @queue.
*
* Since: 1.2.0
*/
gboolean
gst_data_queue_push (GstDataQueue * queue, GstDataQueueItem * item)
{
GstDataQueuePrivate *priv = queue->priv;
g_return_val_if_fail (GST_IS_DATA_QUEUE (queue), FALSE);
g_return_val_if_fail (item != NULL, FALSE);
GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);
STATUS (queue, "before pushing");
/* We ALWAYS need to check for queue fillness */
if (gst_data_queue_locked_is_full (queue)) {
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
if (G_LIKELY (priv->fullcallback))
priv->fullcallback (queue, priv->checkdata);
else
g_signal_emit (queue, gst_data_queue_signals[SIGNAL_FULL], 0);
GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);
/* signal might have removed some items */
while (gst_data_queue_locked_is_full (queue)) {
priv->waiting_del = TRUE;
g_cond_wait (&priv->item_del, &priv->qlock);
priv->waiting_del = FALSE;
if (priv->flushing)
goto flushing;
}
}
gst_queue_array_push_tail (priv->queue, item);
if (item->visible)
priv->cur_level.visible++;
priv->cur_level.bytes += item->size;
priv->cur_level.time += item->duration;
STATUS (queue, "after pushing");
if (priv->waiting_add)
g_cond_signal (&priv->item_add);
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
return TRUE;
/* ERRORS */
flushing:
{
GST_DEBUG ("queue:%p, we are flushing", queue);
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
return FALSE;
}
}
static gboolean
_gst_data_queue_wait_non_empty (GstDataQueue * queue)
{
GstDataQueuePrivate *priv = queue->priv;
while (gst_data_queue_locked_is_empty (queue)) {
priv->waiting_add = TRUE;
g_cond_wait (&priv->item_add, &priv->qlock);
priv->waiting_add = FALSE;
if (priv->flushing)
return FALSE;
}
return TRUE;
}
/**
* gst_data_queue_pop:
* @queue: a #GstDataQueue.
* @item: pointer to store the returned #GstDataQueueItem.
*
* Retrieves the first @item available on the @queue. If the queue is currently
* empty, the call will block until at least one item is available, OR the
* @queue is set to the flushing state.
* MT safe.
*
* Returns: #TRUE if an @item was successfully retrieved from the @queue.
*
* Since: 1.2.0
*/
gboolean
gst_data_queue_pop (GstDataQueue * queue, GstDataQueueItem ** item)
{
GstDataQueuePrivate *priv = queue->priv;
g_return_val_if_fail (GST_IS_DATA_QUEUE (queue), FALSE);
g_return_val_if_fail (item != NULL, FALSE);
GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);
STATUS (queue, "before popping");
if (gst_data_queue_locked_is_empty (queue)) {
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
if (G_LIKELY (priv->emptycallback))
priv->emptycallback (queue, priv->checkdata);
else
g_signal_emit (queue, gst_data_queue_signals[SIGNAL_EMPTY], 0);
GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);
if (!_gst_data_queue_wait_non_empty (queue))
goto flushing;
}
/* Get the item from the GQueue */
*item = gst_queue_array_pop_head (priv->queue);
/* update current level counter */
if ((*item)->visible)
priv->cur_level.visible--;
priv->cur_level.bytes -= (*item)->size;
priv->cur_level.time -= (*item)->duration;
STATUS (queue, "after popping");
if (priv->waiting_del)
g_cond_signal (&priv->item_del);
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
return TRUE;
/* ERRORS */
flushing:
{
GST_DEBUG ("queue:%p, we are flushing", queue);
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
return FALSE;
}
}
static gint
is_of_type (gconstpointer a, gconstpointer b)
{
return !G_TYPE_CHECK_INSTANCE_TYPE (a, GPOINTER_TO_SIZE (b));
}
/**
* gst_data_queue_peek:
* @queue: a #GstDataQueue.
* @item: pointer to store the returned #GstDataQueueItem.
*
* Retrieves the first @item available on the @queue without removing it.
* If the queue is currently empty, the call will block until at least
* one item is available, OR the @queue is set to the flushing state.
* MT safe.
*
* Returns: #TRUE if an @item was successfully retrieved from the @queue.
*
* Since: 1.2.0
*/
gboolean
gst_data_queue_peek (GstDataQueue * queue, GstDataQueueItem ** item)
{
GstDataQueuePrivate *priv = queue->priv;
g_return_val_if_fail (GST_IS_DATA_QUEUE (queue), FALSE);
g_return_val_if_fail (item != NULL, FALSE);
GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);
STATUS (queue, "before peeking");
if (gst_data_queue_locked_is_empty (queue)) {
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
if (G_LIKELY (priv->emptycallback))
priv->emptycallback (queue, priv->checkdata);
else
g_signal_emit (queue, gst_data_queue_signals[SIGNAL_EMPTY], 0);
GST_DATA_QUEUE_MUTEX_LOCK_CHECK (queue, flushing);
if (!_gst_data_queue_wait_non_empty (queue))
goto flushing;
}
/* Get the item from the GQueue */
*item = gst_queue_array_peek_head (priv->queue);
STATUS (queue, "after peeking");
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
return TRUE;
/* ERRORS */
flushing:
{
GST_DEBUG ("queue:%p, we are flushing", queue);
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
return FALSE;
}
}
/**
* gst_data_queue_drop_head:
* @queue: The #GstDataQueue to drop an item from.
* @type: The #GType of the item to drop.
*
* Pop and unref the head-most #GstMiniObject with the given #GType.
*
* Returns: TRUE if an element was removed.
*
* Since: 1.2.0
*/
gboolean
gst_data_queue_drop_head (GstDataQueue * queue, GType type)
{
gboolean res = FALSE;
GstDataQueueItem *leak = NULL;
guint idx;
GstDataQueuePrivate *priv = queue->priv;
g_return_val_if_fail (GST_IS_DATA_QUEUE (queue), FALSE);
GST_DEBUG ("queue:%p", queue);
GST_DATA_QUEUE_MUTEX_LOCK (queue);
idx = gst_queue_array_find (priv->queue, is_of_type, GSIZE_TO_POINTER (type));
if (idx == -1)
goto done;
leak = gst_queue_array_drop_element (priv->queue, idx);
if (leak->visible)
priv->cur_level.visible--;
priv->cur_level.bytes -= leak->size;
priv->cur_level.time -= leak->duration;
leak->destroy (leak);
res = TRUE;
done:
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
GST_DEBUG ("queue:%p , res:%d", queue, res);
return res;
}
/**
* gst_data_queue_limits_changed:
* @queue: The #GstDataQueue
*
* Inform the queue that the limits for the fullness check have changed and that
* any blocking gst_data_queue_push() should be unblocked to recheck the limts.
*
* Since: 1.2.0
*/
void
gst_data_queue_limits_changed (GstDataQueue * queue)
{
GstDataQueuePrivate *priv = queue->priv;
g_return_if_fail (GST_IS_DATA_QUEUE (queue));
GST_DATA_QUEUE_MUTEX_LOCK (queue);
if (priv->waiting_del) {
GST_DEBUG ("signal del");
g_cond_signal (&priv->item_del);
}
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
}
/**
* gst_data_queue_get_level:
* @queue: The #GstDataQueue
* @level: the location to store the result
*
* Get the current level of the queue.
*
* Since: 1.2.0
*/
void
gst_data_queue_get_level (GstDataQueue * queue, GstDataQueueSize * level)
{
GstDataQueuePrivate *priv = queue->priv;
memcpy (level, (&priv->cur_level), sizeof (GstDataQueueSize));
}
static void
gst_data_queue_set_property (GObject * object,
guint prop_id, const GValue * value, GParamSpec * pspec)
{
switch (prop_id) {
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_data_queue_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
GstDataQueue *queue = GST_DATA_QUEUE (object);
GstDataQueuePrivate *priv = queue->priv;
GST_DATA_QUEUE_MUTEX_LOCK (queue);
switch (prop_id) {
case PROP_CUR_LEVEL_BYTES:
g_value_set_uint (value, priv->cur_level.bytes);
break;
case PROP_CUR_LEVEL_VISIBLE:
g_value_set_uint (value, priv->cur_level.visible);
break;
case PROP_CUR_LEVEL_TIME:
g_value_set_uint64 (value, priv->cur_level.time);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
GST_DATA_QUEUE_MUTEX_UNLOCK (queue);
}