gstreamer/gst/gstiterator.c
Wim Taymans 767d9e4681 More MT fixes, added design document describing refcounting policies used in GStreamer and locking involved.
Original commit message from CVS:
* docs/design/part-MT-refcounting.txt:
* docs/design/part-conventions.txt:
* gst/gstbin.c: (gst_bin_set_index), (gst_bin_set_clock),
(gst_bin_add_func), (gst_bin_remove_func),
(gst_bin_iterate_elements), (gst_bin_change_state),
(gst_bin_dispose), (gst_bin_get_by_name_recurse_up):
* gst/gstcaps.c:
* gst/gstelement.c: (gst_element_add_pad),
(gst_element_remove_pad), (pad_compare_name),
(gst_element_get_static_pad), (gst_element_get_request_pad),
(gst_element_get_pad), (gst_element_iterate_pads),
(gst_element_class_get_pad_template_list),
(gst_element_class_get_pad_template), (gst_element_get_random_pad),
(gst_element_get_event_masks), (gst_element_send_event),
(gst_element_seek), (gst_element_get_query_types),
(gst_element_query), (gst_element_get_formats),
(gst_element_convert), (gst_element_post_message),
(gst_element_set_locked_state), (gst_element_get_state),
(gst_element_set_state), (gst_element_pads_activate),
(gst_element_dispose), (gst_element_set_manager_func),
(gst_element_get_manager):
* gst/gstelement.h:
* gst/gstiterator.c: (gst_iterator_new), (gst_list_iterator_next),
(gst_list_iterator_resync), (gst_list_iterator_free),
(gst_iterator_new_list):
* gst/gstiterator.h:
* gst/gstmessage.c: (_gst_message_copy):
* gst/gstobject.c: (gst_object_class_init), (gst_object_init),
(gst_object_ref), (gst_object_unref), (gst_object_sink),
(gst_object_replace), (gst_object_dispose),
(gst_object_dispatch_properties_changed), (gst_object_set_name),
(gst_object_set_parent), (gst_object_get_parent),
(gst_object_unparent), (gst_object_check_uniqueness),
(gst_object_get_path_string):
* gst/gstobject.h:
* gst/gstpad.c: (gst_pad_dispose), (gst_pad_set_active),
(gst_pad_is_active), (gst_pad_set_blocked_async),
(gst_pad_is_blocked), (gst_pad_unlink), (gst_pad_is_linked),
(gst_pad_link_prepare_filtered), (gst_pad_link_filtered),
(gst_pad_get_real_parent), (gst_pad_relink_filtered),
(gst_pad_get_peer), (gst_pad_realize), (gst_pad_get_allowed_caps),
(gst_pad_alloc_buffer), (gst_pad_push), (gst_pad_pull),
(gst_pad_pull_range), (gst_pad_push_event):
* gst/gstpad.h:
* gst/gstpipeline.c: (gst_pipeline_init), (gst_pipeline_dispose),
(is_eos), (pipeline_bus_handler):
* gst/gstutils.c: (gst_element_get_compatible_pad_filtered),
(gst_element_link_pads_filtered), (gst_element_unlink):
* gst/parse/grammar.y:
* tools/gst-compprep.c: (main):
* tools/gst-inspect.c: (print_pad_info):
* tools/gst-launch.c: (main):
* tools/gst-xmlinspect.c: (print_element_info):
More MT fixes, added design document describing refcounting
policies used in GStreamer and locking involved.
Fixed unsafe ghostpad dereffing.
Removed old unsafe methods.
2004-12-13 11:33:55 +00:00

333 lines
7.7 KiB
C

/* GStreamer
* Copyright (C) 2004 Wim Taymans <wim@fluendo.com>
*
* gstiterator.h: Base class for iterating lists.
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "gst_private.h"
#include <gst/gstiterator.h>
static void
gst_iterator_init (GstIterator * it,
GMutex * lock,
guint32 * master_cookie,
GstIteratorNextFunction next,
GstIteratorResyncFunction resync, GstIteratorFreeFunction free)
{
it->lock = lock;
it->master_cookie = master_cookie;
it->cookie = *master_cookie;
it->next = next;
it->resync = resync;
it->free = free;
}
GstIterator *
gst_iterator_new (guint size,
GMutex * lock,
guint32 * master_cookie,
GstIteratorNextFunction next,
GstIteratorResyncFunction resync, GstIteratorFreeFunction free)
{
GstIterator *result;
g_return_val_if_fail (size >= sizeof (GstIterator), NULL);
g_return_val_if_fail (master_cookie != NULL, NULL);
g_return_val_if_fail (next != NULL, NULL);
g_return_val_if_fail (resync != NULL, NULL);
g_return_val_if_fail (free != NULL, NULL);
result = g_malloc (size);
gst_iterator_init (result, lock, master_cookie, next, resync, free);
return result;
}
/*
* list iterator
*/
typedef struct _GstListIterator
{
GstIterator iterator;
gpointer owner;
GList **orig;
GList *list; /* pointer in list */
GstIteratorRefFunction reffunc;
GstIteratorUnrefFunction unreffunc;
GstIteratorDisposeFunction freefunc;
} GstListIterator;
static GstIteratorResult
gst_list_iterator_next (GstListIterator * it, gpointer * elem)
{
if (it->list == NULL)
return GST_ITERATOR_DONE;
*elem = it->list->data;
if (it->reffunc) {
it->reffunc (*elem);
}
it->list = g_list_next (it->list);
return GST_ITERATOR_OK;
}
static void
gst_list_iterator_resync (GstListIterator * it)
{
it->list = *it->orig;
}
static void
gst_list_iterator_free (GstListIterator * it)
{
if (it->freefunc) {
it->freefunc (it->owner);
}
g_free (it);
}
GstIterator *
gst_iterator_new_list (GMutex * lock,
guint32 * master_cookie,
GList ** list,
gpointer owner,
GstIteratorRefFunction ref,
GstIteratorUnrefFunction unref, GstIteratorDisposeFunction free)
{
GstListIterator *result;
/* no need to lock, nothing can change here */
result = (GstListIterator *) gst_iterator_new (sizeof (GstListIterator),
lock,
master_cookie,
(GstIteratorNextFunction) gst_list_iterator_next,
(GstIteratorResyncFunction) gst_list_iterator_resync,
(GstIteratorFreeFunction) gst_list_iterator_free);
result->owner = owner;
result->orig = list;
result->list = *list;
result->reffunc = ref;
result->unreffunc = unref;
result->freefunc = free;
return GST_ITERATOR (result);
}
GstIteratorResult
gst_iterator_next (GstIterator * it, gpointer * elem)
{
GstIteratorResult result;
g_return_val_if_fail (it != NULL, GST_ITERATOR_ERROR);
g_return_val_if_fail (elem != NULL, GST_ITERATOR_ERROR);
if (it->lock)
g_mutex_lock (it->lock);
if (*it->master_cookie != it->cookie) {
result = GST_ITERATOR_RESYNC;
goto done;
}
result = it->next (it, elem);
done:
if (it->lock)
g_mutex_unlock (it->lock);
return result;
}
void
gst_iterator_resync (GstIterator * it)
{
g_return_if_fail (it != NULL);
if (it->lock)
g_mutex_lock (it->lock);
it->resync (it);
it->cookie = *it->master_cookie;
if (it->lock)
g_mutex_unlock (it->lock);
}
void
gst_iterator_free (GstIterator * it)
{
g_return_if_fail (it != NULL);
it->free (it);
}
typedef struct _GstIteratorFilter
{
GstIterator iterator;
GstIterator *slave;
GCompareFunc func;
gpointer user_data;
gboolean compare;
gboolean first;
gboolean found;
} GstIteratorFilter;
static GstIteratorResult
filter_next (GstIteratorFilter * it, gpointer * elem)
{
GstIteratorResult result;
gboolean done = FALSE;
*elem = NULL;
if (it->found)
return GST_ITERATOR_DONE;
while (!done) {
gpointer item;
result = gst_iterator_next (it->slave, &item);
switch (result) {
case GST_ITERATOR_OK:
if (GST_ITERATOR (it)->lock)
g_mutex_unlock (GST_ITERATOR (it)->lock);
if (it->compare) {
if (it->func (item, it->user_data) == 0) {
*elem = item;
done = TRUE;
if (it->first)
it->found = TRUE;
}
} else {
it->func (item, it->user_data);
}
if (GST_ITERATOR (it)->lock)
g_mutex_lock (GST_ITERATOR (it)->lock);
break;
case GST_ITERATOR_RESYNC:
case GST_ITERATOR_DONE:
done = TRUE;
break;
default:
g_assert_not_reached ();
break;
}
}
return result;
}
static void
filter_resync (GstIteratorFilter * it)
{
gst_iterator_resync (it->slave);
it->found = FALSE;
}
static void
filter_uninit (GstIteratorFilter * it)
{
it->slave->lock = GST_ITERATOR (it)->lock;
}
static void
filter_free (GstIteratorFilter * it)
{
filter_uninit (it);
gst_iterator_free (it->slave);
g_free (it);
}
GstIterator *
gst_iterator_filter (GstIterator * it, gpointer user_data, GCompareFunc func)
{
GstIteratorFilter *result;
g_return_val_if_fail (it != NULL, NULL);
g_return_val_if_fail (func != NULL, NULL);
result = (GstIteratorFilter *) gst_iterator_new (sizeof (GstIteratorFilter),
it->lock, it->master_cookie,
(GstIteratorNextFunction) filter_next,
(GstIteratorResyncFunction) filter_resync,
(GstIteratorFreeFunction) filter_free);
it->lock = NULL;
result->func = func;
result->user_data = user_data;
result->slave = it;
result->compare = TRUE;
result->first = FALSE;
result->found = FALSE;
return GST_ITERATOR (result);
}
void
gst_iterator_foreach (GstIterator * it, GFunc function, gpointer user_data)
{
GstIteratorFilter filter;
gpointer dummy;
g_return_if_fail (it != NULL);
g_return_if_fail (function != NULL);
gst_iterator_init (GST_ITERATOR (&filter),
it->lock, it->master_cookie,
(GstIteratorNextFunction) filter_next,
(GstIteratorResyncFunction) filter_resync,
(GstIteratorFreeFunction) filter_uninit);
it->lock = NULL;
filter.func = (GCompareFunc) function;
filter.user_data = user_data;
filter.slave = it;
filter.compare = FALSE;
filter.first = FALSE;
filter.found = FALSE;
gst_iterator_next (GST_ITERATOR (&filter), &dummy);
gst_iterator_free (GST_ITERATOR (&filter));
}
gpointer
gst_iterator_find_custom (GstIterator * it, gpointer user_data,
GCompareFunc func)
{
GstIteratorFilter filter;
gpointer result = NULL;
g_return_val_if_fail (it != NULL, NULL);
g_return_val_if_fail (func != NULL, NULL);
gst_iterator_init (GST_ITERATOR (&filter),
it->lock, it->master_cookie,
(GstIteratorNextFunction) filter_next,
(GstIteratorResyncFunction) filter_resync,
(GstIteratorFreeFunction) filter_uninit);
it->lock = NULL;
filter.func = func;
filter.user_data = user_data;
filter.slave = it;
filter.compare = TRUE;
filter.first = TRUE;
filter.found = FALSE;
gst_iterator_next (GST_ITERATOR (&filter), &result);
gst_iterator_free (GST_ITERATOR (&filter));
return result;
}