From 527701a8f2d3cc85687c1b4810b99f6f92595e76 Mon Sep 17 00:00:00 2001
From: Markus Handell <handellm@webrtc.org>
Date: Thu, 20 Apr 2023 09:37:00 +0200
Subject: [PATCH] Increase tracing fidelity for investigation.

This CL adds tracing for investigating issues reported by
Intel when testing out VSyncDecoding.

Bug: chromium:1434747
Change-Id: If2f62fa4ac9fd2fba4e34daabcb5933a4cc395cb
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/301982
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Auto-Submit: Markus Handell <handellm@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Markus Handell <handellm@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#39904}
---
 video/BUILD.gn               | 1 +
 video/decode_synchronizer.cc | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/video/BUILD.gn b/video/BUILD.gn
index 544f2c5a1c..78b6e78d14 100644
--- a/video/BUILD.gn
+++ b/video/BUILD.gn
@@ -345,6 +345,7 @@ rtc_library("decode_synchronizer") {
     "../api/units:time_delta",
     "../api/units:timestamp",
     "../rtc_base:checks",
+    "../rtc_base:event_tracer",
     "../rtc_base:logging",
     "../rtc_base:macromagic",
   ]
diff --git a/video/decode_synchronizer.cc b/video/decode_synchronizer.cc
index e676acfcf0..2b9a658426 100644
--- a/video/decode_synchronizer.cc
+++ b/video/decode_synchronizer.cc
@@ -20,6 +20,7 @@
 #include "api/units/timestamp.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/logging.h"
+#include "rtc_base/trace_event.h"
 #include "video/frame_decode_scheduler.h"
 #include "video/frame_decode_timing.h"
 
@@ -117,6 +118,7 @@ DecodeSynchronizer::~DecodeSynchronizer() {
 
 std::unique_ptr<FrameDecodeScheduler>
 DecodeSynchronizer::CreateSynchronizedFrameScheduler() {
+  TRACE_EVENT0("webrtc", __func__);
   RTC_DCHECK_RUN_ON(worker_queue_);
   auto scheduler = std::make_unique<SynchronizedFrameDecodeScheduler>(this);
   auto [it, inserted] = schedulers_.emplace(scheduler.get());
@@ -157,6 +159,7 @@ void DecodeSynchronizer::OnFrameScheduled(
 
 void DecodeSynchronizer::RemoveFrameScheduler(
     SynchronizedFrameDecodeScheduler* scheduler) {
+  TRACE_EVENT0("webrtc", __func__);
   RTC_DCHECK_RUN_ON(worker_queue_);
   RTC_DCHECK(scheduler);
   auto it = schedulers_.find(scheduler);
@@ -177,6 +180,7 @@ void DecodeSynchronizer::ScheduleNextTick() {
 }
 
 void DecodeSynchronizer::OnTick() {
+  TRACE_EVENT0("webrtc", __func__);
   RTC_DCHECK_RUN_ON(worker_queue_);
   expected_next_tick_ = clock_->CurrentTime() + metronome_->TickPeriod();