From a0f6ff101e781aaf0a931be6e22f2885f4f69e04 Mon Sep 17 00:00:00 2001 From: Ray Strode Date: Mon, 22 Jun 2020 17:13:54 -0400 Subject: [PATCH] x11: ensure some context is bound before calling glClientWaitSync Since commit 972134abe48a4c9c7b6ad41b0723f30f4e7ae16b we now call glClientWaitSync for the vendor nvidia driver, to know when a frame is ready for the compositor to process. glClientWaitSync can be called regardless of which context is currently bound, but if no context is bound at all, it returns 0 without doing anything. This commit checks for that edge case, and ensures a context gets made current in the event no context is already current, before calling glClientWaitSync. --- gdk/x11/gdkglcontext-x11.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/gdk/x11/gdkglcontext-x11.c b/gdk/x11/gdkglcontext-x11.c index 834d23ac93..d9e30ad09e 100644 --- a/gdk/x11/gdkglcontext-x11.c +++ b/gdk/x11/gdkglcontext-x11.c @@ -606,6 +606,14 @@ on_gl_surface_xevent (GdkGLContext *context, { GLenum wait_result; + /* We don't care if the passed context is the current context, + * necessarily, but we do care that *some* context is bound, + * otherwise, the GL dispatch layer will make glClientWaitSync() + * silently return 0. + */ + if (glXGetCurrentContext () == NULL) + gdk_gl_context_make_current (context); + wait_result = glClientWaitSync (context_x11->frame_fence, 0, 0); switch (wait_result)