commit 07b27ce1b6a8646d0fc7236be7d75210e4011be8
author Alec Mouri <alecmouri@google.com> Mon Apr 26 16:31:44 2021 -0700
committer Alec Mouri <alecmouri@google.com> Mon Apr 26 17:24:37 2021 -0700
tree 9ac186be9f9160b6170d7c6a70a4f1d55484d577
parent 9d53391338e6f76bcadcefae389d913e68ad05d7

Add rate limiting to fps reporter.

From a user perspective, the jittery frame rate is jarring, and from a
performance perspective submitting a binder call every frame is
overkill. To address those two concerns add rate-limiting from
SurfaceFlinger to limit the frame rate reporting.

As part of this patch, extract OneShotTimer's fake clock interface to a
SF-common location so that FpsReporter can share that interface for
testing.

Bug: 186265654
Test: Manually inspect fps overlay
Test: libsurfaceflinger_unittest
Change-Id: I45eb994d847abbb9fc8d5ff7d07ad51a1a790176

services/surfaceflinger/Scheduler/OneShotTimer.cpp

diff --git a/services/surfaceflinger/Scheduler/OneShotTimer.cpp b/services/surfaceflinger/Scheduler/OneShotTimer.cpp
index d659398..16f041a 100644
--- a/services/surfaceflinger/Scheduler/OneShotTimer.cpp
+++ b/services/surfaceflinger/Scheduler/OneShotTimer.cpp
@@ -15,7 +15,6 @@
  */
 
 #include "OneShotTimer.h"
-
 #include <utils/Log.h>
 #include <utils/Timers.h>
 #include <chrono>
@@ -40,14 +39,9 @@
 namespace android {
 namespace scheduler {
 
-std::chrono::steady_clock::time_point OneShotTimer::Clock::now() const {
-    return std::chrono::steady_clock::now();
-}
-
 OneShotTimer::OneShotTimer(std::string name, const Interval& interval,
                            const ResetCallback& resetCallback,
-                           const TimeoutCallback& timeoutCallback,
-                           std::unique_ptr<OneShotTimer::Clock> clock)
+                           const TimeoutCallback& timeoutCallback, std::unique_ptr<Clock> clock)
       : mClock(std::move(clock)),
         mName(std::move(name)),
         mInterval(interval),

services/surfaceflinger/Scheduler/OneShotTimer.h

diff --git a/services/surfaceflinger/Scheduler/OneShotTimer.h b/services/surfaceflinger/Scheduler/OneShotTimer.h
index 7285427..09265bb 100644
--- a/services/surfaceflinger/Scheduler/OneShotTimer.h
+++ b/services/surfaceflinger/Scheduler/OneShotTimer.h
@@ -20,6 +20,7 @@
 #include <chrono>
 #include <condition_variable>
 #include <thread>
+#include "../Clock.h"
 
 #include <android-base/thread_annotations.h>
 
@@ -36,17 +37,9 @@
     using ResetCallback = std::function<void()>;
     using TimeoutCallback = std::function<void()>;
 
-    class Clock {
-    public:
-        Clock() = default;
-        virtual ~Clock() = default;
-
-        virtual std::chrono::steady_clock::time_point now() const;
-    };
-
     OneShotTimer(std::string name, const Interval& interval, const ResetCallback& resetCallback,
                  const TimeoutCallback& timeoutCallback,
-                 std::unique_ptr<OneShotTimer::Clock> = std::make_unique<OneShotTimer::Clock>());
+                 std::unique_ptr<Clock> clock = std::make_unique<SteadyClock>());
     ~OneShotTimer();
 
     // Initializes and turns on the idle timer.