gstreamer/gst-libs/gst/gl/gstgldisplay.c
Matthew Waters bcce615263 gl: add a scary note about initializing thread support for the winsys
We cannot do it as the winsys may crash if we initialize too late.

Example, GLX contexts with Intel drivers:
Intel requires the X Display to be the same in order to share GL
resources across GL contexts.  These GL contexts are generally
accessed from different threads.  Without winsys support it is
nearly impossible to guarentee that concurrent access will not
occur.  This concurrent access could result in crashes or abortion
by the winsys (xcb).

https://bugzilla.gnome.org/show_bug.cgi?id=731525
2017-12-09 19:31:43 +00:00

244 lines
6.9 KiB
C

/*
* GStreamer
* Copyright (C) 2007 David A. Schleef <ds@schleef.org>
* Copyright (C) 2008 Julien Isorce <julien.isorce@gmail.com>
* Copyright (C) 2008 Filippo Argiolas <filippo.argiolas@gmail.com>
* Copyright (C) 2013 Matthew Waters <ystreet00@gmail.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.
*/
/**
* SECTION:gstgldisplay
* @short_description: window system display connection abstraction
* @title: GstGLDisplay
* @see_also: #GstContext, #GstGLContext, #GstGLWindow
*
* #GstGLDisplay represents a connection to the underlying windowing system.
* Elements are required to make use of #GstContext to share and propogate
* a #GstGLDisplay.
*
* <note>Certain window systems require a special function to be called to
* initialize threading support. As this GStreamer GL library does not preclude
* concurrent access to the windowing system, it is strongly advised that
* applications ensure that threading support has been initialized before any
* other toolkit/library functionality is accessed. Failure to do so could
* result in sudden application abortion during execution. The most notably
* example of such a function is X11's XInitThreads().</note>
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "gl.h"
#include "gstgldisplay.h"
#if GST_GL_HAVE_WINDOW_X11
#include <gst/gl/x11/gstgldisplay_x11.h>
#endif
#if GST_GL_HAVE_PLATFORM_EGL
#include <gst/gl/egl/gstgldisplay_egl.h>
#include <gst/gl/egl/gsteglimagememory.h>
#endif
GST_DEBUG_CATEGORY_STATIC (gst_context);
GST_DEBUG_CATEGORY_STATIC (gst_gl_display_debug);
#define GST_CAT_DEFAULT gst_gl_display_debug
#define DEBUG_INIT \
GST_DEBUG_CATEGORY_INIT (gst_gl_display_debug, "gldisplay", 0, "opengl display"); \
GST_DEBUG_CATEGORY_GET (gst_context, "GST_CONTEXT");
G_DEFINE_TYPE_WITH_CODE (GstGLDisplay, gst_gl_display, GST_TYPE_OBJECT,
DEBUG_INIT);
#define GST_GL_DISPLAY_GET_PRIVATE(o) \
(G_TYPE_INSTANCE_GET_PRIVATE((o), GST_TYPE_GL_DISPLAY, GstGLDisplayPrivate))
static void gst_gl_display_finalize (GObject * object);
static guintptr gst_gl_display_default_get_handle (GstGLDisplay * display);
struct _GstGLDisplayPrivate
{
gint dummy;
};
static void
gst_gl_display_class_init (GstGLDisplayClass * klass)
{
g_type_class_add_private (klass, sizeof (GstGLDisplayPrivate));
klass->get_handle = gst_gl_display_default_get_handle;
G_OBJECT_CLASS (klass)->finalize = gst_gl_display_finalize;
}
static void
gst_gl_display_init (GstGLDisplay * display)
{
display->priv = GST_GL_DISPLAY_GET_PRIVATE (display);
display->type = GST_GL_DISPLAY_TYPE_ANY;
GST_TRACE ("init %p", display);
gst_gl_memory_init ();
#if GST_GL_HAVE_PLATFORM_EGL
gst_egl_image_memory_init ();
#endif
}
static void
gst_gl_display_finalize (GObject * object)
{
GST_TRACE ("finalize %p", object);
G_OBJECT_CLASS (gst_gl_display_parent_class)->finalize (object);
}
/**
* gst_gl_display_new:
*
* Returns: (transfer full): a new #GstGLDisplay
*/
GstGLDisplay *
gst_gl_display_new (void)
{
GstGLDisplay *display = NULL;
const gchar *user_choice, *platform_choice;
static volatile gsize _init = 0;
if (g_once_init_enter (&_init)) {
GST_DEBUG_CATEGORY_INIT (gst_gl_display_debug, "gldisplay", 0,
"gldisplay element");
g_once_init_leave (&_init, 1);
}
user_choice = g_getenv ("GST_GL_WINDOW");
platform_choice = g_getenv ("GST_GL_PLATFORM");
GST_INFO ("creating a display, user choice:%s (platform: %s)",
GST_STR_NULL (user_choice), GST_STR_NULL (platform_choice));
#if GST_GL_HAVE_WINDOW_COCOA
if (!display && (!user_choice || g_strstr_len (user_choice, 5, "cocoa")))
display = g_object_new (GST_TYPE_GL_DISPLAY, NULL);
#endif
#if GST_GL_HAVE_WINDOW_X11
if (!display && (!user_choice || g_strstr_len (user_choice, 3, "x11")))
display = GST_GL_DISPLAY (gst_gl_display_x11_new (NULL));
#endif
#if GST_GL_HAVE_WINDOW_WAYLAND
if (!display && (!user_choice || g_strstr_len (user_choice, 7, "wayland")))
display = g_object_new (GST_TYPE_GL_DISPLAY, NULL);
#endif
#if GST_GL_HAVE_PLATFORM_EGL
if (!display && (!platform_choice
|| g_strstr_len (platform_choice, 3, "egl")))
display = GST_GL_DISPLAY (gst_gl_display_egl_new ());
#endif
if (!display) {
/* subclass returned a NULL window */
GST_WARNING ("Could not create display. user specified %s "
"(platform: %s), creating dummy",
GST_STR_NULL (user_choice), GST_STR_NULL (platform_choice));
return g_object_new (GST_TYPE_GL_DISPLAY, NULL);
}
return display;
}
guintptr
gst_gl_display_get_handle (GstGLDisplay * display)
{
GstGLDisplayClass *klass;
g_return_val_if_fail (GST_IS_GL_DISPLAY (display), 0);
klass = GST_GL_DISPLAY_GET_CLASS (display);
g_return_val_if_fail (klass->get_handle != NULL, 0);
return klass->get_handle (display);
}
static guintptr
gst_gl_display_default_get_handle (GstGLDisplay * display)
{
return 0;
}
/**
* gst_gl_display_get_handle_type:
* @display: a #GstGLDisplay
*
* Returns: the #GstGLDisplayType of @display
*/
GstGLDisplayType
gst_gl_display_get_handle_type (GstGLDisplay * display)
{
g_return_val_if_fail (GST_IS_GL_DISPLAY (display), GST_GL_DISPLAY_TYPE_NONE);
return display->type;
}
/**
* gst_context_set_gl_display:
* @context: a #GstContext
* @display: resulting #GstGLDisplay
*
* Sets @display on @context
*/
void
gst_context_set_gl_display (GstContext * context, GstGLDisplay * display)
{
GstStructure *s;
g_return_if_fail (context != NULL);
GST_CAT_LOG (gst_context, "setting GstGLDisplay(%p) on context(%p)", display,
context);
s = gst_context_writable_structure (context);
gst_structure_set (s, GST_GL_DISPLAY_CONTEXT_TYPE, GST_TYPE_GL_DISPLAY,
display, NULL);
}
/**
* gst_context_get_gl_display:
* @context: a #GstContext
* @display: resulting #GstGLDisplay
*
* Returns: Whether @display was in @context
*/
gboolean
gst_context_get_gl_display (GstContext * context, GstGLDisplay ** display)
{
const GstStructure *s;
gboolean ret;
g_return_val_if_fail (display != NULL, FALSE);
g_return_val_if_fail (context != NULL, FALSE);
s = gst_context_get_structure (context);
ret = gst_structure_get (s, GST_GL_DISPLAY_CONTEXT_TYPE,
GST_TYPE_GL_DISPLAY, display, NULL);
GST_CAT_LOG (gst_context, "got GstGLDisplay(%p) from context(%p)", *display,
context);
return ret;
}