From 151188d1e330a7a5f110bbc8251680121a1a84a6 Mon Sep 17 00:00:00 2001 From: Kai Chen Date: Mon, 7 Aug 2017 08:34:51 -0700 Subject: [PATCH] egl/wayland: Use roundtrips when awaiting buffer release In get_back_bo, we use wl_display_dispatch_queue() to block and wait for a buffer release event. However, not all Wayland compositors flush the client socket on posting a buffer-release event, so by only blocking client-side, we may block indefinitely, or at least need to wait for an input event / frame completion to arrive for the compositor to flush. We now use dispatch_queue as a first pass, but if our entire buffer pool is exhausted, use a roundtrip (an immediately-triggered wl_callback) to ensure that the compositor flushes out our release event immediately. [daniels: Modified comment and commit message.] Signed-off-by: Kai Chen Reviewed-by: Daniel Stone CC: --- src/egl/drivers/dri2/platform_wayland.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/src/egl/drivers/dri2/platform_wayland.c b/src/egl/drivers/dri2/platform_wayland.c index 15dc9390cb3..0b6cd1d1167 100644 --- a/src/egl/drivers/dri2/platform_wayland.c +++ b/src/egl/drivers/dri2/platform_wayland.c @@ -383,8 +383,13 @@ get_back_bo(struct dri2_egl_surface *dri2_surf) break; /* If we don't have a buffer, then block on the server to release one for - * us, and try again. */ - if (wl_display_dispatch_queue(dri2_dpy->wl_dpy, dri2_surf->wl_queue) < 0) + * us, and try again. wl_display_dispatch_queue will process any pending + * events, however not all servers flush on issuing a buffer release + * event. So, we spam the server with roundtrips as they always cause a + * client flush. + */ + if (wl_display_roundtrip_queue(dri2_dpy->wl_dpy, + dri2_surf->wl_queue) < 0) return -1; } -- 2.30.2