[client] wayland: measure presentation time

client/displayservers/Wayland/CMakeLists.txt

@@ -31,6 +31,7 @@ add_library(displayserver_Wayland STATIC
 	input.c
 	output.c
 	poll.c
+	presentation.c
 	state.c
 	registry.c
 	wayland.c
@@ -74,6 +75,9 @@ include_directories("${CMAKE_BINARY_DIR}/wayland")
 wayland_generate(
     "${WAYLAND_PROTOCOLS_BASE}/stable/xdg-shell/xdg-shell.xml"
     "${CMAKE_BINARY_DIR}/wayland/wayland-xdg-shell-client-protocol")
+wayland_generate(
+    "${WAYLAND_PROTOCOLS_BASE}/stable/presentation-time/presentation-time.xml"
+    "${CMAKE_BINARY_DIR}/wayland/wayland-presentation-time-client-protocol")
 wayland_generate(
     "${WAYLAND_PROTOCOLS_BASE}/unstable/xdg-decoration/xdg-decoration-unstable-v1.xml"
     "${CMAKE_BINARY_DIR}/wayland/wayland-xdg-decoration-unstable-v1-client-protocol")
@@ -89,4 +93,3 @@ wayland_generate(
 wayland_generate(
     "${WAYLAND_PROTOCOLS_BASE}/unstable/idle-inhibit/idle-inhibit-unstable-v1.xml"
     "${CMAKE_BINARY_DIR}/wayland/wayland-idle-inhibit-unstable-v1-client-protocol")
-

client/displayservers/Wayland/gl.c

@@ -110,10 +110,14 @@ void waylandEGLSwapBuffers(EGLDisplay display, EGLSurface surface, const struct
       wlWm.eglDamageRects[i*4+3] = damage[i].h;
     }
 
+    waylandPresentationFrame();
     wlWm.eglSwapWithDamage(display, surface, wlWm.eglDamageRects, count);
   }
   else
+  {
+    waylandPresentationFrame();
     eglSwapBuffers(display, surface);
+  }
 
   if (wlWm.needsResize)
   {

client/displayservers/Wayland/presentation.c

@@ -0,0 +1,110 @@
+/**
+ * Looking Glass
+ * Copyright (C) 2017-2021 The Looking Glass Authors
+ * https://looking-glass.io
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc., 59
+ * Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#define _GNU_SOURCE
+#include "wayland.h"
+
+#include <stdbool.h>
+#include <string.h>
+#include <errno.h>
+
+#include <wayland-client.h>
+
+#include "common/debug.h"
+#include "common/time.h"
+
+struct FrameData
+{
+  struct timespec sent;
+};
+
+static void presentationClockId(void * data,
+    struct wp_presentation * presentation, uint32_t clkId)
+{
+  wlWm.clkId = clkId;
+}
+
+static const struct wp_presentation_listener presentationListener = {
+  .clock_id = presentationClockId,
+};
+
+static void presentationFeedbackSyncOutput(void * data,
+    struct wp_presentation_feedback * feedback, struct wl_output * output)
+{
+  // Do nothing.
+}
+
+static void presentationFeedbackPresented(void * opaque,
+    struct wp_presentation_feedback * feedback, uint32_t tvSecHi, uint32_t tvSecLo,
+    uint32_t tvNsec, uint32_t refresh, uint32_t seqHi, uint32_t seqLo, uint32_t flags)
+{
+  struct FrameData * data = opaque;
+  struct timespec present = {
+    .tv_sec = (uint64_t) tvSecHi << 32 | tvSecLo,
+    .tv_nsec = tvNsec,
+  };
+  struct timespec delta;
+
+  tsDiff(&delta, &present, &data->sent);
+  printf("Presented in %3jd.%06lums, vsync: %d, hw_clock: %d, hw_compl: %d, zero_copy: %d\n",
+      (intmax_t) delta.tv_sec * 1000 + delta.tv_nsec / 1000000, delta.tv_nsec % 1000000,
+      (bool) (flags & WP_PRESENTATION_FEEDBACK_KIND_VSYNC),
+      (bool) (flags & WP_PRESENTATION_FEEDBACK_KIND_HW_CLOCK),
+      (bool) (flags & WP_PRESENTATION_FEEDBACK_KIND_HW_COMPLETION),
+      (bool) (flags & WP_PRESENTATION_FEEDBACK_KIND_ZERO_COPY));
+  free(data);
+}
+
+static void presentationFeedbackDiscarded(void * data,
+    struct wp_presentation_feedback * feedback)
+{
+  free(data);
+}
+
+static const struct wp_presentation_feedback_listener presentationFeedbackListener = {
+  .sync_output = presentationFeedbackSyncOutput,
+  .presented = presentationFeedbackPresented,
+  .discarded = presentationFeedbackDiscarded,
+};
+
+bool waylandPresentationInit(void)
+{
+  if (wlWm.presentation)
+    wp_presentation_add_listener(wlWm.presentation, &presentationListener, NULL);
+  return true;
+}
+
+void waylandPresentationFree(void)
+{
+  wp_presentation_destroy(wlWm.presentation);
+}
+
+void waylandPresentationFrame(void)
+{
+  struct FrameData * data = malloc(sizeof(struct FrameData));
+  if (clock_gettime(wlWm.clkId, &data->sent))
+  {
+    DEBUG_ERROR("clock_gettime failed: %s\n", strerror(errno));
+    free(data);
+  }
+
+  struct wp_presentation_feedback * feedback = wp_presentation_feedback(wlWm.presentation, wlWm.surface);
+  wp_presentation_feedback_add_listener(feedback, &presentationFeedbackListener, data);
+}

client/displayservers/Wayland/registry.c

@@ -47,6 +47,9 @@ static void registryGlobalHandler(void * data, struct wl_registry * registry,
     wlWm.xdgDecorationManager = wl_registry_bind(wlWm.registry, name,
         &zxdg_decoration_manager_v1_interface, 1);
 #endif
+  else if (!strcmp(interface, wp_presentation_interface.name))
+    wlWm.presentation = wl_registry_bind(wlWm.registry, name,
+        &wp_presentation_interface, 1);
   else if (!strcmp(interface, zwp_relative_pointer_manager_v1_interface.name))
     wlWm.relativePointerManager = wl_registry_bind(wlWm.registry, name,
         &zwp_relative_pointer_manager_v1_interface, 1);

client/displayservers/Wayland/wayland.c

@@ -84,6 +84,9 @@ static bool waylandInit(const LG_DSInitParams params)
   if (!waylandIdleInit())
     return false;
 
+  if (!waylandPresentationInit())
+    return false;
+
   if (!waylandInputInit())
     return false;
 

client/displayservers/Wayland/wayland.h

@@ -35,6 +35,7 @@
 #include "interface/displayserver.h"
 
 #include "wayland-xdg-shell-client-protocol.h"
+#include "wayland-presentation-time-client-protocol.h"
 #include "wayland-xdg-decoration-unstable-v1-client-protocol.h"
 #include "wayland-keyboard-shortcuts-inhibit-unstable-v1-client-protocol.h"
 #include "wayland-pointer-constraints-unstable-v1-client-protocol.h"
@@ -110,6 +111,9 @@ struct WaylandDSState
   EGLSurface glSurface;
 #endif
 
+  struct wp_presentation * presentation;
+  clockid_t clkId;
+
 #ifdef ENABLE_LIBDECOR
   struct libdecor * libdecor;
   struct libdecor_frame * libdecorFrame;
@@ -255,6 +259,11 @@ void waylandWait(unsigned int time);
 bool waylandPollRegister(int fd, WaylandPollCallback callback, void * opaque, uint32_t events);
 bool waylandPollUnregister(int fd);
 
+// presentation module
+bool waylandPresentationInit(void);
+void waylandPresentationFrame(void);
+void waylandPresentationFree(void);
+
 // registry module
 bool waylandRegistryInit(void);
 void waylandRegistryFree(void);