[client] scheduler: qualify presentation feedback

Track cadence, interruption, and calibration wake reasons independently
across X11 and Wayland. Feed phase correction back only when a pure
cadence wake renders the exact frame that was queued at that wake.

Propagate EGL swap results through the display-server boundary. Reject
failed presentations and keep pending Wayland HDR descriptions inactive
until the preceding surface commit succeeds.

client/displayservers/Wayland/gl.c

@@ -228,8 +228,11 @@ static const struct wp_image_description_v1_listener hdrImageDescListener =
   .ready2 = hdrImageDescReadyV2,
 };
 
-void waylandEGLSwapBuffers(EGLDisplay display, EGLSurface surface, const struct Rect * damage, int count)
+bool waylandEGLSwapBuffers(EGLDisplay display, EGLSurface surface,
+    const struct Rect * damage, int count)
 {
+  bool result = false;
+
   // EGL presentation sends a batch of Wayland requests ending in a surface
   // commit. A concurrent commit would apply a partial batch and, when explicit
   // sync is active, omit one of the required acquire/release timeline points.
@@ -248,8 +251,10 @@ void waylandEGLSwapBuffers(EGLDisplay display, EGLSurface surface, const struct
 
     waylandPresentationFrame();
     applyHDRPending();
-    swapWithDamage(&wlWm.swapWithDamage, display, surface, damage, count);
-    activateReadyHDRImageDesc();
+    result = swapWithDamage(
+        &wlWm.swapWithDamage, display, surface, damage, count);
+    if (result)
+      activateReadyHDRImageDesc();
   });
 
   if (wlWm.needsResize)
@@ -305,6 +310,7 @@ void waylandEGLSwapBuffers(EGLDisplay display, EGLSurface surface, const struct
   }
 
   wlWm.desktop->shellAckConfigureIfNeeded();
+  return result;
 }
 #endif
 
@@ -750,6 +756,6 @@ void waylandGLSetSwapInterval(int interval)
 
 void waylandGLSwapBuffers(void)
 {
-  waylandEGLSwapBuffers(wlWm.glDisplay, wlWm.glSurface, NULL, 0);
+  (void)waylandEGLSwapBuffers(wlWm.glDisplay, wlWm.glSurface, NULL, 0);
 }
 #endif

client/displayservers/Wayland/wayland.h

@@ -267,7 +267,8 @@ struct WaylandDSState
   enum WaylandHDRPendingAction pendingHDRAction;
   struct WaylandHDRParameters  pendingHDR;
 
-  LGEvent * frameEvent;
+  _Atomic(unsigned) frameEventFlags;
+  LGEvent *         frameEvent;
 
   struct wl_list poll; // WaylandPoll::link
   struct wl_list pollFree; // WaylandPoll::link
@@ -333,7 +334,8 @@ void waylandCursorScaleChange(void);
 #if defined(ENABLE_EGL) || defined(ENABLE_OPENGL)
 bool waylandEGLInit(int w, int h);
 EGLDisplay waylandGetEGLDisplay(void);
-void waylandEGLSwapBuffers(EGLDisplay display, EGLSurface surface, const struct Rect * damage, int count);
+bool waylandEGLSwapBuffers(EGLDisplay display, EGLSurface surface,
+    const struct Rect * damage, int count);
 #endif
 
 #ifdef ENABLE_EGL
@@ -421,7 +423,7 @@ void waylandWindowFree(void);
 void waylandWindowUpdateScale(void);
 void waylandSetWindowSize(int x, int y);
 bool waylandIsValidPointerPos(int x, int y);
-bool waylandWaitFrame(void);
+LG_DSWaitFrameResult waylandWaitFrame(void);
 void waylandSkipFrame(void);
 void waylandStopWaitFrame(void);
 void waylandNeedsResize(void);

client/displayservers/Wayland/window.c

@@ -113,6 +113,13 @@ static const struct wl_surface_listener wlSurfaceListener = {
   .leave = wlSurfaceLeaveHandler,
 };
 
+static void waylandSignalFrame(LG_DSWaitFrameResult result)
+{
+  atomic_fetch_or_explicit(
+      &wlWm.frameEventFlags, result, memory_order_release);
+  lgSignalEvent(wlWm.frameEvent);
+}
+
 static void fractionalScalePreferredScale(void * data,
     struct wp_fractional_scale_v1 * fractionalScale, uint32_t scale)
 {
@@ -133,7 +140,7 @@ bool waylandWindowInit(const char * title, const char * appId, bool fullscreen,
     DEBUG_ERROR("Failed to initialize event for waitFrame");
     return false;
   }
-  lgSignalEvent(wlWm.frameEvent);
+  waylandSignalFrame(LG_DS_WAIT_FRAME_INTERRUPTED);
 
   if (!wlWm.compositor)
   {
@@ -220,7 +227,7 @@ bool waylandIsValidPointerPos(int x, int y)
 
 static void frameHandler(void * opaque, struct wl_callback * callback, unsigned int data)
 {
-  lgSignalEvent(wlWm.frameEvent);
+  waylandSignalFrame(LG_DS_WAIT_FRAME_CADENCE);
   wl_callback_destroy(callback);
 }
 
@@ -228,9 +235,11 @@ static const struct wl_callback_listener frame_listener = {
    .done = frameHandler,
 };
 
-bool waylandWaitFrame(void)
+LG_DSWaitFrameResult waylandWaitFrame(void)
 {
   lgWaitEvent(wlWm.frameEvent, TIMEOUT_INFINITE);
+  const LG_DSWaitFrameResult result = atomic_exchange_explicit(
+      &wlWm.frameEventFlags, LG_DS_WAIT_FRAME_NONE, memory_order_acquire);
 
   INTERLOCKED_SECTION(wlWm.surfaceLock,
   {
@@ -239,7 +248,7 @@ bool waylandWaitFrame(void)
       wl_callback_add_listener(callback, &frame_listener, NULL);
   });
 
-  return false;
+  return result;
 }
 
 void waylandSkipFrame(void)
@@ -253,5 +262,5 @@ void waylandSkipFrame(void)
 
 void waylandStopWaitFrame(void)
 {
-  lgSignalEvent(wlWm.frameEvent);
+  waylandSignalFrame(LG_DS_WAIT_FRAME_INTERRUPTED);
 }