commit 029cc12ba5834559839da900ee999754e6ca1dd6
author Dominik Laskowski <domlaskowski@google.com> Wed Jan 23 19:52:06 2019 -0800
committer Dominik Laskowski <domlaskowski@google.com> Sat Jan 26 16:06:07 2019 -0800
tree f331d3cc87e44242d9a14f45fc8fbcf4e40c3994
parent bf9a49a2aa80e4dffa88064be9e16371077257c6

SF: Toggle VSYNC in EventThread with state machine

This CL simplifies the logic to enable and disable VSYNC in the
EventThread loop.

Bug: 74619554
Test: libsurfaceflinger_unittest
Test: dumpsys SurfaceFlinger --vsync

Change-Id: I7637fcf1982d60cfced5dae68c74556f0ee67a0f

services/surfaceflinger/Scheduler/EventThread.h

diff --git a/services/surfaceflinger/Scheduler/EventThread.h b/services/surfaceflinger/Scheduler/EventThread.h
index 1a8ebb7..f093e47 100644
--- a/services/surfaceflinger/Scheduler/EventThread.h
+++ b/services/surfaceflinger/Scheduler/EventThread.h
@@ -176,9 +176,6 @@
     void removeDisplayEventConnectionLocked(const wp<EventThreadConnection>& connection)
             REQUIRES(mMutex);
 
-    void enableVSyncLocked() REQUIRES(mMutex);
-    void disableVSyncLocked() REQUIRES(mMutex);
-
     // Implements VSyncSource::Callback
     void onVSyncEvent(nsecs_t timestamp) override;
 
@@ -212,11 +209,17 @@
 
     VSyncState mVSyncState GUARDED_BY(mMutex);
 
-    bool mVsyncEnabled GUARDED_BY(mMutex) = false;
-    bool mKeepRunning GUARDED_BY(mMutex) = true;
+    // State machine for event loop.
+    enum class State {
+        Idle,
+        Quit,
+        SyntheticVSync,
+        VSync,
+    };
 
-    // for debugging
-    bool mDebugVsyncEnabled GUARDED_BY(mMutex) = false;
+    State mState GUARDED_BY(mMutex) = State::Idle;
+
+    static const char* toCString(State);
 
     // Callback that resets the idle timer when the next vsync is received.
     ResetIdleTimerCallback mResetIdleTimer;