commit 3a3815a6a6e0e082a6f5bf7827c234315b5e2563
author Ady Abraham <adyabr@google.com> Thu Dec 23 14:32:07 2021 -0800
committer Ady Abraham <adyabr@google.com> Fri Jan 07 03:39:48 2022 +0000
tree c61ed50d35f5eb9d0f9bfa3ffac3e59adb9d686a
parent 5f0ef012302cdedf4e8f4e5ddfe5210d793c1b28

SF: call the timer's callback in case of an error

Bug: 210065990
Test: new SF unit test
Change-Id: I4ae70e82e9402fc7d7eecc1a17c1b992eb3efab6

services/surfaceflinger/Scheduler/Timer.cpp

diff --git a/services/surfaceflinger/Scheduler/Timer.cpp b/services/surfaceflinger/Scheduler/Timer.cpp
index 22c3a70..68f9321 100644
--- a/services/surfaceflinger/Scheduler/Timer.cpp
+++ b/services/surfaceflinger/Scheduler/Timer.cpp
@@ -51,13 +51,25 @@
 }
 
 void Timer::reset() {
-    cleanup();
-    mTimerFd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC | TFD_NONBLOCK);
-    mEpollFd = epoll_create1(EPOLL_CLOEXEC);
-    if (pipe2(mPipes.data(), O_CLOEXEC | O_NONBLOCK)) {
-        ALOGE("could not create TimerDispatch mPipes");
-        return;
-    };
+    std::function<void()> cb;
+    {
+        std::lock_guard lock(mMutex);
+        if (mExpectingCallback && mCallback) {
+            cb = mCallback;
+        }
+
+        cleanup();
+        mTimerFd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC | TFD_NONBLOCK);
+        mEpollFd = epoll_create1(EPOLL_CLOEXEC);
+        if (pipe2(mPipes.data(), O_CLOEXEC | O_NONBLOCK)) {
+            ALOGE("could not create TimerDispatch mPipes");
+        }
+    }
+    if (cb) {
+        setDebugState(DebugState::InCallback);
+        cb();
+        setDebugState(DebugState::Running);
+    }
     setDebugState(DebugState::Reset);
 }
 
@@ -81,6 +93,8 @@
         close(mPipes[kWritePipe]);
         mPipes[kWritePipe] = -1;
     }
+    mExpectingCallback = false;
+    mCallback = {};
 }
 
 void Timer::endDispatch() {
@@ -99,6 +113,7 @@
             std::chrono::duration_cast<std::chrono::nanoseconds>(1s).count();
 
     mCallback = cb;
+    mExpectingCallback = true;
 
     struct itimerspec old_timer;
     struct itimerspec new_timer {
@@ -198,6 +213,7 @@
                 {
                     std::lock_guard lock(mMutex);
                     cb = mCallback;
+                    mExpectingCallback = false;
                 }
                 if (cb) {
                     setDebugState(DebugState::InCallback);

services/surfaceflinger/Scheduler/Timer.h

diff --git a/services/surfaceflinger/Scheduler/Timer.h b/services/surfaceflinger/Scheduler/Timer.h
index 628d800..eb65954 100644
--- a/services/surfaceflinger/Scheduler/Timer.h
+++ b/services/surfaceflinger/Scheduler/Timer.h
@@ -36,6 +36,10 @@
     void alarmCancel() final;
     void dump(std::string& result) const final;
 
+protected:
+    // For unit testing
+    int mEpollFd = -1;
+
 private:
     enum class DebugState {
         Reset,
@@ -48,12 +52,12 @@
         ftl_last = Terminated
     };
 
-    void reset();
-    void cleanup();
+    void reset() EXCLUDES(mMutex);
+    void cleanup() REQUIRES(mMutex);
     void setDebugState(DebugState state) EXCLUDES(mMutex);
 
     int mTimerFd = -1;
-    int mEpollFd = -1;
+
     std::array<int, 2> mPipes = {-1, -1};
 
     std::thread mDispatchThread;
@@ -63,6 +67,7 @@
 
     mutable std::mutex mMutex;
     std::function<void()> mCallback GUARDED_BY(mMutex);
+    bool mExpectingCallback GUARDED_BY(mMutex) = false;
     DebugState mDebugState GUARDED_BY(mMutex);
 };