[Bf-blender-cvs] [bbe7183cd39] master: GHOST/Wayland: fix threaded event handling

[Campbell Barton]

Commit: bbe7183cd39de1417f27d2558bb717dd1aa1081d
Author: Campbell Barton
Date:   Fri Jan 13 17:48:50 2023 +1100
Branches: master
https://developer.blender.org/rBbbe7183cd39de1417f27d2558bb717dd1aa1081d

GHOST/Wayland: fix threaded event handling

The previous fix from T100855 [0] no longer works on my system
(3.4.1 release also fails for GNOME/KDE/WLROOTS compositors).

Resolve by removing the loop from the wait-on-file handle check.
Also reduce locking/unlocking calls.

[0]: 37b256e26feb454d9febd84dac1b1ce8b8d84d90

===================================================================

M	intern/ghost/intern/GHOST_SystemWayland.cpp

===================================================================

diff --git a/intern/ghost/intern/GHOST_SystemWayland.cpp b/intern/ghost/intern/GHOST_SystemWayland.cpp
index d823db2afd7..ef8ccd66685 100644
--- a/intern/ghost/intern/GHOST_SystemWayland.cpp
+++ b/intern/ghost/intern/GHOST_SystemWayland.cpp
@@ -1669,24 +1669,24 @@ static int ghost_wl_display_event_pump_from_thread(struct wl_display *wl_display
     else {
       wl_display_cancel_read(wl_display);
     }
+
+    server_mutex->unlock();
   }
   else {
-    int state;
-    do {
-      server_mutex->unlock();
-      /* Wait for input (unlocked, so as not to block other threads). */
-      state = file_descriptor_is_io_ready(fd, GWL_IOR_READ | GWL_IOR_NO_RETRY, INT32_MAX);
+    server_mutex->unlock();
+
+    /* Wait for input (unlocked, so as not to block other threads). */
+    int state = file_descriptor_is_io_ready(fd, GWL_IOR_READ | GWL_IOR_NO_RETRY, INT32_MAX);
+    /* Re-check `state` with a lock held, needed to avoid holding the lock. */
+    if (state > 0) {
       server_mutex->lock();
-      /* Re-check `state` with a lock held, needed to avoid holding the lock. */
+      state = file_descriptor_is_io_ready(fd, GWL_IOR_READ | GWL_IOR_NO_RETRY, 0);
       if (state > 0) {
-        state = file_descriptor_is_io_ready(fd, GWL_IOR_READ | GWL_IOR_NO_RETRY, 0);
-        if (state > 0) {
-          err = wl_display_dispatch_pending(wl_display);
-        }
+        err = wl_display_dispatch_pending(wl_display);
       }
-    } while (state > 0);
+      server_mutex->unlock();
+    }
   }
-  server_mutex->unlock();
 
   return err;
 }