Bug 1470901 - Record scene build, scene swap, and render times in telemetry. r=sotaro

MozReview-Commit-ID: 1a6pqa0sSrU

--HG--
extra : rebase_source : d00f3f4d8d8df889d4b3dc62dd1d5f797093c07a

gfx/layers/wr/WebRenderBridgeParent.cpp

@@ -29,6 +29,7 @@
 #include "mozilla/layers/AsyncImagePipelineManager.h"
 #include "mozilla/layers/WebRenderImageHost.h"
 #include "mozilla/layers/WebRenderTextureHost.h"
+#include "mozilla/Telemetry.h"
 #include "mozilla/TimeStamp.h"
 #include "mozilla/Unused.h"
 #include "mozilla/webrender/RenderThread.h"
@@ -124,6 +125,26 @@ gecko_profiler_unregister_thread()
   PROFILER_UNREGISTER_THREAD();
 }
 
+void
+record_telemetry_time(mozilla::wr::TelemetryProbe aProbe, uint64_t aTimeNs)
+{
+  uint32_t time_ms = (uint32_t)(aTimeNs / 1000000);
+  switch (aProbe) {
+    case mozilla::wr::TelemetryProbe::SceneBuildTime:
+      mozilla::Telemetry::Accumulate(mozilla::Telemetry::WR_SCENEBUILD_TIME, time_ms);
+      break;
+    case mozilla::wr::TelemetryProbe::SceneSwapTime:
+      mozilla::Telemetry::Accumulate(mozilla::Telemetry::WR_SCENESWAP_TIME, time_ms);
+      break;
+    case mozilla::wr::TelemetryProbe::RenderTime:
+      mozilla::Telemetry::Accumulate(mozilla::Telemetry::WR_RENDER_TIME, time_ms);
+      break;
+    default:
+      MOZ_ASSERT(false);
+      break;
+  }
+}
+
 namespace mozilla {
 
 namespace layers {

gfx/webrender_bindings/src/bindings.rs

@@ -462,6 +462,13 @@ fn get_proc_address(glcontext_ptr: *mut c_void,
     symbol as *const _
 }
 
+#[repr(C)]
+pub enum TelemetryProbe {
+    SceneBuildTime = 0,
+    SceneSwapTime = 1,
+    RenderTime = 2,
+}
+
 extern "C" {
     fn is_in_compositor_thread() -> bool;
     fn is_in_render_thread() -> bool;
@@ -481,6 +488,7 @@ extern "C" {
     #[allow(dead_code)]
     fn gfx_critical_error(msg: *const c_char);
     fn gfx_critical_note(msg: *const c_char);
+    fn record_telemetry_time(probe: TelemetryProbe, time_ns: u64);
 }
 
 struct CppNotifier {
@@ -515,8 +523,11 @@ impl RenderNotifier for CppNotifier {
                        _: DocumentId,
                        _scrolled: bool,
                        composite_needed: bool,
-                       _render_time_ns: Option<u64>) {
+                       render_time_ns: Option<u64>) {
         unsafe {
+            if let Some(time) = render_time_ns {
+                record_telemetry_time(TelemetryProbe::RenderTime, time);
+            }
             if composite_needed {
                 wr_notifier_new_frame_ready(self.window_id);
             } else {
@@ -718,13 +729,19 @@ impl SceneBuilderHooks for APZCallbacks {
         unsafe { apz_register_updater(self.window_id) }
     }
 
-    fn pre_scene_swap(&self, _scenebuild_time: u64) {
-        unsafe { apz_pre_scene_swap(self.window_id) }
+    fn pre_scene_swap(&self, scenebuild_time: u64) {
+        unsafe {
+            record_telemetry_time(TelemetryProbe::SceneBuildTime, scenebuild_time);
+            apz_pre_scene_swap(self.window_id);
+        }
     }
 
-    fn post_scene_swap(&self, info: PipelineInfo, _sceneswap_time: u64) {
+    fn post_scene_swap(&self, info: PipelineInfo, sceneswap_time: u64) {
         let info = WrPipelineInfo::new(info);
-        unsafe { apz_post_scene_swap(self.window_id, info) }
+        unsafe {
+            record_telemetry_time(TelemetryProbe::SceneSwapTime, sceneswap_time);
+            apz_post_scene_swap(self.window_id, info);
+        }
 
         // After a scene swap we should schedule a render for the next vsync,
         // otherwise there's no guarantee that the new scene will get rendered

gfx/webrender_bindings/webrender_ffi.h

@@ -127,4 +127,10 @@ void apz_deregister_sampler(mozilla::wr::WrWindowId aWindowId);
 #undef WR_FUNC
 #undef WR_DESTRUCTOR_SAFE_FUNC
 
+// More functions invoked from Rust code. These are down here because they
+// refer to data structures from webrender_ffi_generated.h
+extern "C" {
+void record_telemetry_time(mozilla::wr::TelemetryProbe aProbe, uint64_t aTimeNs);
+}
+
 #endif // WR_h

gfx/webrender_bindings/webrender_ffi_generated.h

@@ -152,6 +152,14 @@ enum class RepeatMode : uint32_t {
   Sentinel /* this must be last for serialization purposes. */
 };
 
+enum class TelemetryProbe {
+  SceneBuildTime = 0,
+  SceneSwapTime = 1,
+  RenderTime = 2,
+
+  Sentinel /* this must be last for serialization purposes. */
+};
+
 enum class TransformStyle : uint32_t {
   Flat = 0,
   Preserve3D = 1,
@@ -1005,6 +1013,9 @@ extern bool is_in_main_thread();
 
 extern bool is_in_render_thread();
 
+extern void record_telemetry_time(TelemetryProbe aProbe,
+                                  uint64_t aTimeNs);
+
 WR_INLINE
 bool remove_program_binary_disk_cache(const nsAString *aProfPath)
 WR_FUNC;