syncobj: restore SHM buffer reset (#9675)

reset shm buffers early to mitigate stuttering animations, also reuse
the monitors eglSync and store the eglsync per monitor. this however
reintroduces flickering in dbeaver nonsyncobj application.

1 files changed, 3 insertions, 5 deletions

diff --git a/src/protocols/core/Compositor.cpp b/src/protocols/core/Compositor.cpp
index a9fe33db..a3576c7e 100644
--- a/src/protocols/core/Compositor.cpp
+++ b/src/protocols/core/Compositor.cpp
@@ -471,12 +471,10 @@ void CWLSurfaceResource::commitPendingState(SSurfaceState& state) {
             nullptr);
     }
 
-    // release the buffer if it's synchronous as update() has done everything thats needed
+    // release the buffer if it's synchronous (SHM) as update() has done everything thats needed
     // so we can let the app know we're done.
-    // if (!syncobj && current.buffer && current.buffer->buffer && current.buffer->buffer->isSynchronous()) {
-    // dropCurrentBuffer(); // lets not drop it at all, it will get dropped on next commit if a new buffer arrives.
-    // solves flickering on nonsyncobj apps on explicit sync.
-    // }
+    if (current.buffer && current.buffer->buffer && current.buffer->buffer->isSynchronous())
+        dropCurrentBuffer();
 }
 
 void CWLSurfaceResource::updateCursorShm(CRegion damage) {