[gegl] buffer: use g_usleep instad of g_thread_yield on tile contention

[Øyvind "pippin" Kolås <ok src gnome org>]

commit fd9e903daab667d12c1bca39eb93eea25781d261
Author: Øyvind Kolås <pippin gimp org>
Date:   Sat May 23 20:01:55 2020 +0200

    buffer: use g_usleep instad of g_thread_yield on tile contention
    
    See issue gimp#4955 to work well in the hyper-threading case we actually
    want to sleep for some time instead of keeping the scheduler busy.
    We sleep for 1/1000th of a second which is the resolution g_usleep
    has on win32.

 gegl/buffer/gegl-tile.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/gegl/buffer/gegl-tile.c b/gegl/buffer/gegl-tile.c
index cdc6e4134..51f6f4f7e 100644
--- a/gegl/buffer/gegl-tile.c
+++ b/gegl/buffer/gegl-tile.c
@@ -325,7 +325,7 @@ gegl_tile_lock (GeglTile *tile)
 
       ++count;
       if (count > 32)
-        g_thread_yield ();
+          g_usleep (1000); /* the smallest sleepable time on win32 */
     }
 }