[AChoreographer] Resolves a deadlock
This deadlock could occur when posting a delayed frame callback while a
pending refresh rate callback had not yet been processed by the looper
thread. Resolve the deadlock by releasing the lock in
Choreographer::scheduleCallbacks once the earliest dueTime is retrieved.
Bug: 150731776
Test: ChoreographerNativeTest
Change-Id: I9e1ace12beb4bbc75af0671ddf1b1653d04c9df4
diff --git a/libs/nativedisplay/AChoreographer.cpp b/libs/nativedisplay/AChoreographer.cpp
index 0f7e2fb..0ff33ac 100644
--- a/libs/nativedisplay/AChoreographer.cpp
+++ b/libs/nativedisplay/AChoreographer.cpp
@@ -185,9 +185,18 @@
}
void Choreographer::scheduleCallbacks() {
- AutoMutex _{mLock};
- nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
- if (mFrameCallbacks.top().dueTime <= now) {
+ const nsecs_t now = systemTime(SYSTEM_TIME_MONOTONIC);
+ nsecs_t dueTime;
+ {
+ AutoMutex _{mLock};
+ // If there are no pending callbacks then don't schedule a vsync
+ if (mFrameCallbacks.empty()) {
+ return;
+ }
+ dueTime = mFrameCallbacks.top().dueTime;
+ }
+
+ if (dueTime <= now) {
ALOGV("choreographer %p ~ scheduling vsync", this);
scheduleVsync();
return;