gstreamer/ext/gl/gstglbasemixer.c
Matthew Waters 3548dc5af9 glvideomixer: fix race retrieving the GL context from the display
_get_gl_context() can be called concurrently from either propose_allocation() or
decide_allocation().  If it so happens that this happens at the same time,
the check for whether we already had a GL context was outside the lock.  Inside
the lock and loop, the first thing that happens is that we unref the current GL
context (if valid) as if there was a conflict adding it to the display.  If the
timing was unlucky, subsequent use of the GL context would be referencing an
already unreffed GL context object resulting in a critical:

g_object_ref: assertion 'object->ref_count > 0' failed

https://bugzilla.gnome.org/show_bug.cgi?id=766703
2017-12-09 19:32:20 +00:00

789 lines
21 KiB
C

/* Generic video mixer plugin
*
* GStreamer
* Copyright (C) 2015 Matthew Waters <matthew@centricular.com>
*
* 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.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <gst/gst.h>
#include <gst/video/video.h>
#include "gstglbasemixer.h"
#define gst_gl_base_mixer_parent_class parent_class
G_DEFINE_ABSTRACT_TYPE (GstGLBaseMixer, gst_gl_base_mixer,
GST_TYPE_VIDEO_AGGREGATOR);
static gboolean gst_gl_base_mixer_do_bufferpool (GstGLBaseMixer * mix,
GstCaps * outcaps);
#define GST_CAT_DEFAULT gst_gl_base_mixer_debug
GST_DEBUG_CATEGORY (gst_gl_base_mixer_debug);
static void gst_gl_base_mixer_pad_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static void gst_gl_base_mixer_pad_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_gl_base_mixer_set_context (GstElement * element,
GstContext * context);
static GstStateChangeReturn gst_gl_base_mixer_change_state (GstElement *
element, GstStateChange transition);
enum
{
PROP_PAD_0
};
#define GST_GL_BASE_MIXER_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), GST_TYPE_GL_BASE_MIXER, GstGLBaseMixerPrivate))
struct _GstGLBaseMixerPrivate
{
gboolean negotiated;
GstGLContext *other_context;
GstBufferPool *pool;
GstAllocator *allocator;
GstAllocationParams params;
GstQuery *query;
};
G_DEFINE_TYPE (GstGLBaseMixerPad, gst_gl_base_mixer_pad,
GST_TYPE_VIDEO_AGGREGATOR_PAD);
static void
gst_gl_base_mixer_pad_class_init (GstGLBaseMixerPadClass * klass)
{
GObjectClass *gobject_class = (GObjectClass *) klass;
GstVideoAggregatorPadClass *vaggpad_class =
(GstVideoAggregatorPadClass *) klass;
gobject_class->set_property = gst_gl_base_mixer_pad_set_property;
gobject_class->get_property = gst_gl_base_mixer_pad_get_property;
vaggpad_class->set_info = NULL;
vaggpad_class->prepare_frame = NULL;
vaggpad_class->clean_frame = NULL;
}
static void
gst_gl_base_mixer_pad_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
switch (prop_id) {
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_gl_base_mixer_pad_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 gboolean
_negotiated_caps (GstVideoAggregator * vagg, GstCaps * caps)
{
GstGLBaseMixer *mix = GST_GL_BASE_MIXER (vagg);
return gst_gl_base_mixer_do_bufferpool (mix, caps);
}
static gboolean
_default_propose_allocation (GstGLBaseMixer * mix, GstGLBaseMixerPad * pad,
GstQuery * decide_query, GstQuery * query)
{
return TRUE;
}
static gboolean
gst_gl_base_mixer_sink_event (GstAggregator * agg, GstAggregatorPad * bpad,
GstEvent * event)
{
GstGLBaseMixerPad *pad = GST_GL_BASE_MIXER_PAD (bpad);
switch (GST_EVENT_TYPE (event)) {
case GST_EVENT_CAPS:
if (!GST_AGGREGATOR_CLASS (parent_class)->sink_event (agg, bpad, event))
return FALSE;
pad->negotiated = TRUE;
return TRUE;
default:
break;
}
return GST_AGGREGATOR_CLASS (parent_class)->sink_event (agg, bpad, event);
}
static gboolean
_find_local_gl_context (GstGLBaseMixer * mix)
{
GstQuery *query;
GstContext *context;
const GstStructure *s;
if (mix->context)
return TRUE;
query = gst_query_new_context ("gst.gl.local_context");
if (!mix->context && gst_gl_run_query (GST_ELEMENT (mix), query, GST_PAD_SRC)) {
gst_query_parse_context (query, &context);
if (context) {
s = gst_context_get_structure (context);
gst_structure_get (s, "context", GST_GL_TYPE_CONTEXT, &mix->context,
NULL);
}
}
if (!mix->context
&& gst_gl_run_query (GST_ELEMENT (mix), query, GST_PAD_SINK)) {
gst_query_parse_context (query, &context);
if (context) {
s = gst_context_get_structure (context);
gst_structure_get (s, "context", GST_GL_TYPE_CONTEXT, &mix->context,
NULL);
}
}
GST_DEBUG_OBJECT (mix, "found local context %p", mix->context);
gst_query_unref (query);
if (mix->context)
return TRUE;
return FALSE;
}
static gboolean
_get_gl_context (GstGLBaseMixer * mix)
{
GstGLBaseMixerClass *mix_class = GST_GL_BASE_MIXER_GET_CLASS (mix);
GError *error = NULL;
if (!gst_gl_ensure_element_data (mix, &mix->display,
&mix->priv->other_context))
return FALSE;
gst_gl_display_filter_gl_api (mix->display, mix_class->supported_gl_api);
_find_local_gl_context (mix);
GST_OBJECT_LOCK (mix->display);
if (!mix->context) {
do {
if (mix->context) {
gst_object_unref (mix->context);
mix->context = NULL;
}
/* just get a GL context. we don't care */
mix->context =
gst_gl_display_get_gl_context_for_thread (mix->display, NULL);
if (!mix->context) {
if (!gst_gl_display_create_context (mix->display,
mix->priv->other_context, &mix->context, &error)) {
GST_OBJECT_UNLOCK (mix->display);
goto context_error;
}
}
} while (!gst_gl_display_add_context (mix->display, mix->context));
}
GST_OBJECT_UNLOCK (mix->display);
{
GstGLAPI current_gl_api = gst_gl_context_get_gl_api (mix->context);
if ((current_gl_api & mix_class->supported_gl_api) == 0)
goto unsupported_gl_api;
}
return TRUE;
unsupported_gl_api:
{
GstGLAPI gl_api = gst_gl_context_get_gl_api (mix->context);
gchar *gl_api_str = gst_gl_api_to_string (gl_api);
gchar *supported_gl_api_str =
gst_gl_api_to_string (mix_class->supported_gl_api);
GST_ELEMENT_ERROR (mix, RESOURCE, BUSY,
("GL API's not compatible context: %s supported: %s", gl_api_str,
supported_gl_api_str), (NULL));
g_free (supported_gl_api_str);
g_free (gl_api_str);
return FALSE;
}
context_error:
{
GST_ELEMENT_ERROR (mix, RESOURCE, NOT_FOUND, ("%s", error->message),
(NULL));
g_clear_error (&error);
return FALSE;
}
}
static gboolean
gst_gl_base_mixer_sink_query (GstAggregator * agg, GstAggregatorPad * bpad,
GstQuery * query)
{
gboolean ret = FALSE;
GstGLBaseMixer *mix = GST_GL_BASE_MIXER (agg);
GstGLBaseMixerClass *mix_class = GST_GL_BASE_MIXER_GET_CLASS (mix);
GstGLBaseMixerPad *pad = GST_GL_BASE_MIXER_PAD (bpad);
GST_TRACE ("QUERY %" GST_PTR_FORMAT, query);
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_ALLOCATION:
{
GstQuery *decide_query = NULL;
GST_OBJECT_LOCK (mix);
if (G_UNLIKELY (!pad->negotiated)) {
GST_DEBUG_OBJECT (mix,
"not negotiated yet, can't answer ALLOCATION query");
GST_OBJECT_UNLOCK (mix);
return FALSE;
}
if ((decide_query = mix->priv->query))
gst_query_ref (decide_query);
GST_OBJECT_UNLOCK (mix);
if (!_get_gl_context (mix))
return FALSE;
GST_DEBUG_OBJECT (mix,
"calling propose allocation with query %" GST_PTR_FORMAT,
decide_query);
/* pass the query to the propose_allocation vmethod if any */
if (mix_class->propose_allocation)
ret = mix_class->propose_allocation (mix, pad, decide_query, query);
else
ret = FALSE;
if (decide_query)
gst_query_unref (decide_query);
GST_DEBUG_OBJECT (mix, "ALLOCATION ret %d, %" GST_PTR_FORMAT, ret, query);
return ret;
}
case GST_QUERY_CONTEXT:
{
const gchar *context_type;
GstContext *context, *old_context;
ret = gst_gl_handle_context_query ((GstElement *) mix, query,
&mix->display, &mix->priv->other_context);
if (mix->display)
gst_gl_display_filter_gl_api (mix->display,
mix_class->supported_gl_api);
gst_query_parse_context_type (query, &context_type);
if (g_strcmp0 (context_type, "gst.gl.local_context") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("gst.gl.local_context", FALSE);
s = gst_context_writable_structure (context);
gst_structure_set (s, "context", GST_GL_TYPE_CONTEXT, mix->context,
NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
ret = mix->context != NULL;
}
GST_LOG_OBJECT (mix, "context query of type %s %i", context_type, ret);
if (ret)
return ret;
break;
}
default:
break;
}
return GST_AGGREGATOR_CLASS (parent_class)->sink_query (agg, bpad, query);;
}
static void
gst_gl_base_mixer_pad_init (GstGLBaseMixerPad * mixerpad)
{
}
/* GLBaseMixer signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
PROP_0,
PROP_CONTEXT
};
static gboolean gst_gl_base_mixer_src_query (GstAggregator * agg,
GstQuery * query);
static gboolean
gst_gl_base_mixer_src_activate_mode (GstAggregator * aggregator,
GstPadMode mode, gboolean active);
static gboolean gst_gl_base_mixer_stop (GstAggregator * agg);
static gboolean gst_gl_base_mixer_start (GstAggregator * agg);
static void gst_gl_base_mixer_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_gl_base_mixer_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static gboolean gst_gl_base_mixer_decide_allocation (GstGLBaseMixer * mix,
GstQuery * query);
static gboolean gst_gl_base_mixer_set_allocation (GstGLBaseMixer * mix,
GstBufferPool * pool, GstAllocator * allocator,
GstAllocationParams * params, GstQuery * query);
static void
gst_gl_base_mixer_class_init (GstGLBaseMixerClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *element_class;
GstVideoAggregatorClass *videoaggregator_class =
(GstVideoAggregatorClass *) klass;
GstAggregatorClass *agg_class = (GstAggregatorClass *) klass;
GST_DEBUG_CATEGORY_INIT (GST_CAT_DEFAULT, "glmixer", 0, "opengl mixer");
gobject_class = (GObjectClass *) klass;
element_class = GST_ELEMENT_CLASS (klass);
g_type_class_add_private (klass, sizeof (GstGLBaseMixerPrivate));
gobject_class->get_property = gst_gl_base_mixer_get_property;
gobject_class->set_property = gst_gl_base_mixer_set_property;
element_class->set_context =
GST_DEBUG_FUNCPTR (gst_gl_base_mixer_set_context);
element_class->change_state = gst_gl_base_mixer_change_state;
agg_class->sinkpads_type = GST_TYPE_GL_BASE_MIXER_PAD;
agg_class->sink_query = gst_gl_base_mixer_sink_query;
agg_class->sink_event = gst_gl_base_mixer_sink_event;
agg_class->src_query = gst_gl_base_mixer_src_query;
agg_class->src_activate = gst_gl_base_mixer_src_activate_mode;
agg_class->stop = gst_gl_base_mixer_stop;
agg_class->start = gst_gl_base_mixer_start;
videoaggregator_class->negotiated_caps = _negotiated_caps;
klass->propose_allocation = _default_propose_allocation;
g_object_class_install_property (gobject_class, PROP_CONTEXT,
g_param_spec_object ("context",
"OpenGL context",
"Get OpenGL context",
GST_GL_TYPE_CONTEXT, G_PARAM_READABLE | G_PARAM_STATIC_STRINGS));
/* Register the pad class */
g_type_class_ref (GST_TYPE_GL_BASE_MIXER_PAD);
klass->supported_gl_api = GST_GL_API_ANY;
}
static gboolean
_reset_pad (GstAggregator * self, GstAggregatorPad * base_pad,
gpointer user_data)
{
GstGLBaseMixerPad *mix_pad = GST_GL_BASE_MIXER_PAD (base_pad);
mix_pad->negotiated = FALSE;
return TRUE;
}
static void
gst_gl_base_mixer_reset (GstGLBaseMixer * mix)
{
/* clean up collect data */
gst_aggregator_iterate_sinkpads (GST_AGGREGATOR (mix),
(GstAggregatorPadForeachFunc) _reset_pad, NULL);
}
static void
gst_gl_base_mixer_init (GstGLBaseMixer * mix)
{
mix->priv = GST_GL_BASE_MIXER_GET_PRIVATE (mix);
gst_gl_base_mixer_reset (mix);
}
static void
gst_gl_base_mixer_set_context (GstElement * element, GstContext * context)
{
GstGLBaseMixer *mix = GST_GL_BASE_MIXER (element);
GstGLBaseMixerClass *mix_class = GST_GL_BASE_MIXER_GET_CLASS (mix);
gst_gl_handle_set_context (element, context, &mix->display,
&mix->priv->other_context);
if (mix->display)
gst_gl_display_filter_gl_api (mix->display, mix_class->supported_gl_api);
GST_ELEMENT_CLASS (parent_class)->set_context (element, context);
}
static gboolean
gst_gl_base_mixer_activate (GstGLBaseMixer * mix, gboolean active)
{
GstGLBaseMixerClass *mix_class = GST_GL_BASE_MIXER_GET_CLASS (mix);
gboolean result = TRUE;
if (active) {
if (!gst_gl_ensure_element_data (mix, &mix->display,
&mix->priv->other_context))
return FALSE;
gst_gl_display_filter_gl_api (mix->display, mix_class->supported_gl_api);
}
return result;
}
static gboolean
gst_gl_base_mixer_src_activate_mode (GstAggregator * aggregator,
GstPadMode mode, gboolean active)
{
GstGLBaseMixer *mix;
gboolean result = FALSE;
mix = GST_GL_BASE_MIXER (aggregator);
switch (mode) {
case GST_PAD_MODE_PUSH:
case GST_PAD_MODE_PULL:
result = gst_gl_base_mixer_activate (mix, active);
break;
default:
result = TRUE;
break;
}
return result;
}
static gboolean
gst_gl_base_mixer_src_query (GstAggregator * agg, GstQuery * query)
{
gboolean res = FALSE;
GstGLBaseMixer *mix = GST_GL_BASE_MIXER (agg);
GstGLBaseMixerClass *mix_class = GST_GL_BASE_MIXER_GET_CLASS (mix);
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_CONTEXT:
{
const gchar *context_type;
GstContext *context, *old_context;
res = gst_gl_handle_context_query ((GstElement *) mix, query,
&mix->display, &mix->priv->other_context);
if (mix->display)
gst_gl_display_filter_gl_api (mix->display,
mix_class->supported_gl_api);
gst_query_parse_context_type (query, &context_type);
if (g_strcmp0 (context_type, "gst.gl.local_context") == 0) {
GstStructure *s;
gst_query_parse_context (query, &old_context);
if (old_context)
context = gst_context_copy (old_context);
else
context = gst_context_new ("gst.gl.local_context", FALSE);
s = gst_context_writable_structure (context);
gst_structure_set (s, "context", GST_GL_TYPE_CONTEXT, mix->context,
NULL);
gst_query_set_context (query, context);
gst_context_unref (context);
res = mix->context != NULL;
}
GST_LOG_OBJECT (mix, "context query of type %s %i", context_type, res);
if (res)
return res;
break;
}
default:
break;
}
return GST_AGGREGATOR_CLASS (parent_class)->src_query (agg, query);
}
static gboolean
gst_gl_base_mixer_decide_allocation (GstGLBaseMixer * mix, GstQuery * query)
{
GstGLBaseMixerClass *mix_class = GST_GL_BASE_MIXER_GET_CLASS (mix);
if (!_get_gl_context (mix))
return FALSE;
if (mix_class->decide_allocation)
if (!mix_class->decide_allocation (mix, query))
return FALSE;
return TRUE;
}
/* takes ownership of the pool, allocator and query */
static gboolean
gst_gl_base_mixer_set_allocation (GstGLBaseMixer * mix,
GstBufferPool * pool, GstAllocator * allocator,
GstAllocationParams * params, GstQuery * query)
{
GstAllocator *oldalloc;
GstBufferPool *oldpool;
GstQuery *oldquery;
GstGLBaseMixerPrivate *priv = mix->priv;
GST_DEBUG ("storing allocation query");
GST_OBJECT_LOCK (mix);
oldpool = priv->pool;
priv->pool = pool;
oldalloc = priv->allocator;
priv->allocator = allocator;
oldquery = priv->query;
priv->query = query;
if (params)
priv->params = *params;
else
gst_allocation_params_init (&priv->params);
GST_OBJECT_UNLOCK (mix);
if (oldpool) {
GST_DEBUG_OBJECT (mix, "deactivating old pool %p", oldpool);
gst_buffer_pool_set_active (oldpool, FALSE);
gst_object_unref (oldpool);
}
if (oldalloc) {
gst_object_unref (oldalloc);
}
if (oldquery) {
gst_query_unref (oldquery);
}
return TRUE;
}
static gboolean
gst_gl_base_mixer_do_bufferpool (GstGLBaseMixer * mix, GstCaps * outcaps)
{
GstQuery *query;
gboolean result = TRUE;
GstBufferPool *pool = NULL;
GstAllocator *allocator;
GstAllocationParams params;
GstAggregator *agg = GST_AGGREGATOR (mix);
/* find a pool for the negotiated caps now */
GST_DEBUG_OBJECT (mix, "doing allocation query");
query = gst_query_new_allocation (outcaps, TRUE);
if (!gst_pad_peer_query (agg->srcpad, query)) {
/* not a problem, just debug a little */
GST_DEBUG_OBJECT (mix, "peer ALLOCATION query failed");
}
GST_DEBUG_OBJECT (mix, "calling decide_allocation");
result = gst_gl_base_mixer_decide_allocation (mix, query);
GST_DEBUG_OBJECT (mix, "ALLOCATION (%d) params: %" GST_PTR_FORMAT, result,
query);
if (!result)
goto no_decide_allocation;
/* we got configuration from our peer or the decide_allocation method,
* parse them */
if (gst_query_get_n_allocation_params (query) > 0) {
gst_query_parse_nth_allocation_param (query, 0, &allocator, &params);
} else {
allocator = NULL;
gst_allocation_params_init (&params);
}
if (gst_query_get_n_allocation_pools (query) > 0)
gst_query_parse_nth_allocation_pool (query, 0, &pool, NULL, NULL, NULL);
/* now store */
result =
gst_gl_base_mixer_set_allocation (mix, pool, allocator, &params, query);
return result;
/* Errors */
no_decide_allocation:
{
GST_WARNING_OBJECT (mix, "Failed to decide allocation");
gst_query_unref (query);
return result;
}
}
GstBufferPool *
gst_gl_base_mixer_get_buffer_pool (GstGLBaseMixer * mix)
{
GstBufferPool *pool;
GST_OBJECT_LOCK (mix);
pool = mix->priv->pool;
if (pool)
gst_object_ref (pool);
GST_OBJECT_UNLOCK (mix);
return pool;
}
static void
gst_gl_base_mixer_get_property (GObject * object,
guint prop_id, GValue * value, GParamSpec * pspec)
{
GstGLBaseMixer *mixer = GST_GL_BASE_MIXER (object);
switch (prop_id) {
case PROP_CONTEXT:
g_value_set_object (value, mixer->context);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_gl_base_mixer_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 gboolean
gst_gl_base_mixer_start (GstAggregator * agg)
{
return GST_AGGREGATOR_CLASS (parent_class)->start (agg);;
}
static gboolean
gst_gl_base_mixer_stop (GstAggregator * agg)
{
GstGLBaseMixer *mix = GST_GL_BASE_MIXER (agg);
if (mix->priv->query) {
gst_query_unref (mix->priv->query);
mix->priv->query = NULL;
}
if (mix->priv->pool) {
gst_object_unref (mix->priv->pool);
mix->priv->pool = NULL;
}
if (mix->context) {
gst_object_unref (mix->context);
mix->context = NULL;
}
gst_gl_base_mixer_reset (mix);
return TRUE;
}
static GstStateChangeReturn
gst_gl_base_mixer_change_state (GstElement * element, GstStateChange transition)
{
GstGLBaseMixer *mix = GST_GL_BASE_MIXER (element);
GstGLBaseMixerClass *mix_class = GST_GL_BASE_MIXER_GET_CLASS (mix);
GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
GST_DEBUG_OBJECT (mix, "changing state: %s => %s",
gst_element_state_get_name (GST_STATE_TRANSITION_CURRENT (transition)),
gst_element_state_get_name (GST_STATE_TRANSITION_NEXT (transition)));
switch (transition) {
case GST_STATE_CHANGE_NULL_TO_READY:
if (!gst_gl_ensure_element_data (element, &mix->display,
&mix->priv->other_context))
return GST_STATE_CHANGE_FAILURE;
gst_gl_display_filter_gl_api (mix->display, mix_class->supported_gl_api);
break;
default:
break;
}
ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
if (ret == GST_STATE_CHANGE_FAILURE)
return ret;
switch (transition) {
case GST_STATE_CHANGE_READY_TO_NULL:
if (mix->priv->other_context) {
gst_object_unref (mix->priv->other_context);
mix->priv->other_context = NULL;
}
if (mix->display) {
gst_object_unref (mix->display);
mix->display = NULL;
}
break;
default:
break;
}
return ret;
}