SF: Fix thread safety for scheduler callbacks

SurfaceFlinger::setRefreshRateTo, called from the Scheduler callbacks,
reads HWC and SF state without locking mStateLock, concurrently with
writes from the main thread. This CL registers ResetIdleTimerCallback
per EventThreadConnection, and locks mStateLock for connections used
off the main thread. Note that ExpiredTimerCallback locks mStateLock
unconditionally, since it is always called from the IdleTimer thread.

This CL also adds a thread annotation to setRefreshRateTo, and refactors
it accordingly.

Bug: 123715322
Test: libsurfaceflinger_unittest
Test: Boot with scheduler enabled
Change-Id: Id62c48ae22da38f292ffc18e8731a1c49a0a083c

1 files changed, 11 insertions, 5 deletions

diff --git a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
index ad7dcb4217..2be4fd078e 100644
--- a/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
+++ b/services/surfaceflinger/tests/unittests/EventThreadTest.cpp
@@ -53,8 +53,10 @@ protected:
     class MockEventThreadConnection : public EventThreadConnection {
     public:
         MockEventThreadConnection(android::impl::EventThread* eventThread,
-                                  ResyncCallback&& resyncCallback)
-              : EventThreadConnection(eventThread, std::move(resyncCallback)) {}
+                                  ResyncCallback&& resyncCallback,
+                                  ResetIdleTimerCallback&& resetIdleTimerCallback)
+              : EventThreadConnection(eventThread, std::move(resyncCallback),
+                                      std::move(resetIdleTimerCallback)) {}
         MOCK_METHOD1(postEvent, status_t(const DisplayEventReceiver::Event& event));
     };
 
@@ -82,6 +84,7 @@ protected:
     AsyncCallRecorder<void (*)(VSyncSource::Callback*)> mVSyncSetCallbackCallRecorder;
     AsyncCallRecorder<void (*)(nsecs_t)> mVSyncSetPhaseOffsetCallRecorder;
     AsyncCallRecorder<void (*)()> mResyncCallRecorder;
+    AsyncCallRecorder<void (*)()> mResetIdleTimerCallRecorder;
     AsyncCallRecorder<void (*)(nsecs_t)> mInterceptVSyncCallRecorder;
     ConnectionEventRecorder mConnectionEventCallRecorder{0};
 
@@ -136,7 +139,8 @@ void EventThreadTest::createThread() {
 sp<EventThreadTest::MockEventThreadConnection> EventThreadTest::createConnection(
         ConnectionEventRecorder& recorder) {
     sp<MockEventThreadConnection> connection =
-            new MockEventThreadConnection(mThread.get(), mResyncCallRecorder.getInvocable());
+            new MockEventThreadConnection(mThread.get(), mResyncCallRecorder.getInvocable(),
+                                          mResetIdleTimerCallRecorder.getInvocable());
     EXPECT_CALL(*connection, postEvent(_)).WillRepeatedly(Invoke(recorder.getInvocable()));
     return connection;
 }
@@ -207,6 +211,7 @@ TEST_F(EventThreadTest, canCreateAndDestroyThreadWithNoEventsSent) {
     EXPECT_FALSE(mVSyncSetCallbackCallRecorder.waitForCall(0us).has_value());
     EXPECT_FALSE(mVSyncSetPhaseOffsetCallRecorder.waitForCall(0us).has_value());
     EXPECT_FALSE(mResyncCallRecorder.waitForCall(0us).has_value());
+    EXPECT_FALSE(mResetIdleTimerCallRecorder.waitForCall(0us).has_value());
     EXPECT_FALSE(mInterceptVSyncCallRecorder.waitForCall(0us).has_value());
     EXPECT_FALSE(mConnectionEventCallRecorder.waitForCall(0us).has_value());
 }
@@ -224,9 +229,10 @@ TEST_F(EventThreadTest, vsyncRequestIsIgnoredIfDisplayIsDisconnected) {
 
 TEST_F(EventThreadTest, requestNextVsyncPostsASingleVSyncEventToTheConnection) {
     // Signal that we want the next vsync event to be posted to the connection
-    mThread->requestNextVsync(mConnection, false);
+    mThread->requestNextVsync(mConnection, true);
 
-    // EventThread should immediately request a resync.
+    // EventThread should immediately reset the idle timer and request a resync.
+    EXPECT_TRUE(mResetIdleTimerCallRecorder.waitForCall().has_value());
     EXPECT_TRUE(mResyncCallRecorder.waitForCall().has_value());
 
     // EventThread should enable vsync callbacks.