glcontext: fix race between creation/shutdown

626bcccff9 removed some locks that
allowed the main loop quit to occur before the context was fully
created.

2776cef25d attempted to readd them but
missed the scop of the quit() call.

Also remove the use of g_thread_join() as that's not safe to use when
it's possible to lose the last reference from the GL thread.

https://bugzilla.gnome.org/show_bug.cgi?id=775171
This commit is contained in:
Matthew Waters 2016-11-28 14:19:18 +11:00
parent 2f87392ee7
commit 25fbc6d877

View file

@ -204,6 +204,7 @@ struct _GstGLContextPrivate
/* conditions */
GMutex render_lock;
GCond create_cond;
GCond destroy_cond;
gboolean created;
gboolean alive;
@ -275,6 +276,7 @@ gst_gl_context_init (GstGLContext * context)
g_mutex_init (&context->priv->render_lock);
g_cond_init (&context->priv->create_cond);
g_cond_init (&context->priv->destroy_cond);
context->priv->created = FALSE;
g_weak_ref_init (&context->priv->other_context_ref, NULL);
@ -661,22 +663,20 @@ gst_gl_context_finalize (GObject * object)
gst_gl_window_set_resize_callback (context->window, NULL, NULL, NULL);
gst_gl_window_set_draw_callback (context->window, NULL, NULL, NULL);
g_mutex_lock (&context->priv->render_lock);
if (context->priv->alive) {
GST_INFO_OBJECT (context, "send quit gl window loop");
gst_gl_window_quit (context->window);
GST_INFO_OBJECT (context, "joining gl thread");
g_mutex_lock (&context->priv->render_lock);
if (context->priv->alive) {
GThread *t = context->priv->gl_thread;
g_mutex_unlock (&context->priv->render_lock);
g_thread_join (t);
} else {
g_mutex_unlock (&context->priv->render_lock);
}
while (context->priv->alive)
g_cond_wait (&context->priv->destroy_cond, &context->priv->render_lock);
GST_INFO_OBJECT (context, "gl thread joined");
g_thread_unref (context->priv->gl_thread);
context->priv->gl_thread = NULL;
}
g_mutex_unlock (&context->priv->render_lock);
gst_gl_window_set_close_callback (context->window, NULL, NULL, NULL);
gst_object_unref (context->window);
@ -695,6 +695,7 @@ gst_gl_context_finalize (GObject * object)
g_mutex_clear (&context->priv->render_lock);
g_cond_clear (&context->priv->create_cond);
g_cond_clear (&context->priv->destroy_cond);
g_free (context->priv->gl_exts);
g_weak_ref_clear (&context->priv->other_context_ref);
@ -1291,6 +1292,7 @@ gst_gl_context_create_thread (GstGLContext * context)
}
context->priv->created = FALSE;
g_cond_signal (&context->priv->destroy_cond);
g_mutex_unlock (&context->priv->render_lock);
return NULL;