[Mesa-stable] [PATCH] vulkan/wsi/wayland: Respect non-blocking AcquireNextImage

[Daniel Stone]

If the client has requested that AcquireNextImage not block at all, with
a timeout of 0, then don't make any non-blocking calls.

This will still potentially block infinitely given a non-infinte
timeout, but the fix for that is much more involved.

Signed-off-by: Daniel Stone <daniels at collabora.com>
Cc: mesa-stable at lists.freedesktop.org
Cc: Chad Versace <chadversary at chromium.org>
Cc: Jason Ekstrand <jason at jlekstrand.net>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108540
---
 src/vulkan/wsi/wsi_common_wayland.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/vulkan/wsi/wsi_common_wayland.c b/src/vulkan/wsi/wsi_common_wayland.c
index e9cc22ec603..981243d8b14 100644
--- a/src/vulkan/wsi/wsi_common_wayland.c
+++ b/src/vulkan/wsi/wsi_common_wayland.c
@@ -699,9 +699,14 @@ wsi_wl_swapchain_acquire_next_image(struct wsi_swapchain *wsi_chain,
          }
       }
 
-      /* This time we do a blocking dispatch because we can't go
-       * anywhere until we get an event.
+      /* We now have to do a blocking dispatch, because all our images
+       * are in use and we cannot return one until the server does. However,
+       * if the client has requested non-blocking ANI, then we tell it up front
+       * that we have nothing to return.
        */
+      if (info->timeout == 0)
+         return VK_NOT_READY;
+
       int ret = wl_display_roundtrip_queue(chain->display->wl_display,
                                            chain->display->queue);
       if (ret < 0)
-- 
2.19.1