From c1c6bef99aa49a0bb3f8e99378438e72ffa02fdb Mon Sep 17 00:00:00 2001
From: Markus Handell <handellm@webrtc.org>
Date: Fri, 23 Jul 2021 11:11:32 +0200
Subject: [PATCH] RepeatingTask: equip with DTrace probes.

This change permits dtrace wakeup profiling of Chromium production
builds.

Bug: webrtc:13013
Change-Id: Iff936f7ff03ba7ef349f2bc7d3826a7c8b1bb1b8
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/226461
Commit-Queue: Markus Handell <handellm@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34541}
---
 rtc_base/task_utils/repeating_task.cc |  7 +++++++
 rtc_base/task_utils/repeating_task.h  | 14 +++++++++++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/rtc_base/task_utils/repeating_task.cc b/rtc_base/task_utils/repeating_task.cc
index 9636680cb4..1f3eb1d064 100644
--- a/rtc_base/task_utils/repeating_task.cc
+++ b/rtc_base/task_utils/repeating_task.cc
@@ -70,4 +70,11 @@ bool RepeatingTaskHandle::Running() const {
   return repeating_task_ != nullptr;
 }
 
+namespace webrtc_repeating_task_impl {
+// These methods are empty, but can be externally equipped with actions using
+// dtrace.
+void RepeatingTaskHandleDTraceProbeStart() {}
+void RepeatingTaskHandleDTraceProbeDelayedStart() {}
+void RepeatingTaskImplDTraceProbeRun() {}
+}  // namespace webrtc_repeating_task_impl
 }  // namespace webrtc
diff --git a/rtc_base/task_utils/repeating_task.h b/rtc_base/task_utils/repeating_task.h
index d5066fdb5c..91a40e0714 100644
--- a/rtc_base/task_utils/repeating_task.h
+++ b/rtc_base/task_utils/repeating_task.h
@@ -23,7 +23,14 @@
 #include "system_wrappers/include/clock.h"
 
 namespace webrtc {
+
 namespace webrtc_repeating_task_impl {
+
+// Methods simplifying external tracing of RepeatingTaskHandle operations.
+void RepeatingTaskHandleDTraceProbeStart();
+void RepeatingTaskHandleDTraceProbeDelayedStart();
+void RepeatingTaskImplDTraceProbeRun();
+
 class RepeatingTaskBase : public QueuedTask {
  public:
   RepeatingTaskBase(TaskQueueBase* task_queue,
@@ -67,7 +74,10 @@ class RepeatingTaskImpl final : public RepeatingTaskBase {
   }
 
  private:
-  TimeDelta RunClosure() override { return closure_(); }
+  TimeDelta RunClosure() override {
+    RepeatingTaskImplDTraceProbeRun();
+    return closure_();
+  }
 
   typename std::remove_const<
       typename std::remove_reference<Closure>::type>::type closure_;
@@ -98,6 +108,7 @@ class RepeatingTaskHandle {
                                    Closure&& closure,
                                    Clock* clock = Clock::GetRealTimeClock()) {
     auto alive_flag = PendingTaskSafetyFlag::CreateDetached();
+    webrtc_repeating_task_impl::RepeatingTaskHandleDTraceProbeStart();
     task_queue->PostTask(
         std::make_unique<
             webrtc_repeating_task_impl::RepeatingTaskImpl<Closure>>(
@@ -115,6 +126,7 @@ class RepeatingTaskHandle {
       Closure&& closure,
       Clock* clock = Clock::GetRealTimeClock()) {
     auto alive_flag = PendingTaskSafetyFlag::CreateDetached();
+    webrtc_repeating_task_impl::RepeatingTaskHandleDTraceProbeDelayedStart();
     task_queue->PostDelayedTask(
         std::make_unique<
             webrtc_repeating_task_impl::RepeatingTaskImpl<Closure>>(