SurfaceFlinger: Report stuck fences to client
It's ocassionally observed in traces that the GPU is hung
resulting in fences failing to fire. This normally propagates
back up as an ANR in dequeueBuffers or onFrameAvailable. The ANR
might then pass from the app team, to the HWUI team, to the WM
team, and then if we are lucky enough to get a trace, to the
GPU team. In this CL we allow the client process to monitor
this situation itself, and proactively trigger an ANR with
a more useful and informative message than "stuck in
dequeueBuffers"
Bug: 216160569
Test: Existing tests pass
Change-Id: I3ff93bf57d24268ac57734dfed2df185985ffe1f
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 3bfc2cc..f6f3805 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -3697,12 +3697,13 @@
auto& transaction = transactionQueue.front();
const auto ready =
- transactionIsReadyToBeApplied(transaction.frameTimelineInfo,
- transaction.isAutoTimestamp,
- transaction.desiredPresentTime,
- transaction.originUid, transaction.states,
- bufferLayersReadyToPresent, transactions.size(),
- tryApplyUnsignaled);
+ transactionIsReadyToBeApplied(transaction,
+ transaction.frameTimelineInfo,
+ transaction.isAutoTimestamp,
+ transaction.desiredPresentTime,
+ transaction.originUid, transaction.states,
+ bufferLayersReadyToPresent, transactions.size(),
+ tryApplyUnsignaled);
ATRACE_INT("TransactionReadiness", static_cast<int>(ready));
if (ready == TransactionReadiness::NotReady) {
setTransactionFlags(eTransactionFlushNeeded);
@@ -3779,7 +3780,7 @@
return TransactionReadiness::NotReady;
}
- return transactionIsReadyToBeApplied(transaction.frameTimelineInfo,
+ return transactionIsReadyToBeApplied(transaction, transaction.frameTimelineInfo,
transaction.isAutoTimestamp,
transaction.desiredPresentTime,
transaction.originUid, transaction.states,
@@ -3941,7 +3942,7 @@
return true;
}
-auto SurfaceFlinger::transactionIsReadyToBeApplied(
+auto SurfaceFlinger::transactionIsReadyToBeApplied(TransactionState& transaction,
const FrameTimelineInfo& info, bool isAutoTimestamp, int64_t desiredPresentTime,
uid_t originUid, const Vector<ComposerState>& states,
const std::unordered_map<
@@ -3970,8 +3971,10 @@
}
bool fenceUnsignaled = false;
+ auto queueProcessTime = systemTime();
for (const ComposerState& state : states) {
const layer_state_t& s = state.state;
+
sp<Layer> layer = nullptr;
if (s.surface) {
layer = fromHandle(s.surface).promote();
@@ -4007,6 +4010,15 @@
s.bufferData->acquireFence->getStatus() == Fence::Status::Unsignaled);
if (fenceUnsignaled && !allowLatchUnsignaled) {
+ if (!transaction.sentFenceTimeoutWarning &&
+ queueProcessTime - transaction.queueTime > std::chrono::nanoseconds(4s).count()) {
+ transaction.sentFenceTimeoutWarning = true;
+ auto listener = s.bufferData->releaseBufferListener;
+ if (listener) {
+ listener->onTransactionQueueStalled();
+ }
+ }
+
ATRACE_NAME("fence unsignaled");
return TransactionReadiness::NotReady;
}
@@ -4026,6 +4038,8 @@
}
void SurfaceFlinger::queueTransaction(TransactionState& state) {
+ state.queueTime = systemTime();
+
Mutex::Autolock lock(mQueueLock);
// Generate a CountDownLatch pending state if this is a synchronous transaction.
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 011aaef..0b013d4 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -816,7 +816,7 @@
Ready,
ReadyUnsignaled,
};
- TransactionReadiness transactionIsReadyToBeApplied(
+ TransactionReadiness transactionIsReadyToBeApplied(TransactionState& state,
const FrameTimelineInfo& info, bool isAutoTimestamp, int64_t desiredPresentTime,
uid_t originUid, const Vector<ComposerState>& states,
const std::unordered_map<
diff --git a/services/surfaceflinger/TransactionState.h b/services/surfaceflinger/TransactionState.h
index bab5326..900d566 100644
--- a/services/surfaceflinger/TransactionState.h
+++ b/services/surfaceflinger/TransactionState.h
@@ -98,6 +98,8 @@
int originUid;
uint64_t id;
std::shared_ptr<CountDownLatch> transactionCommittedSignal;
+ int64_t queueTime = 0;
+ bool sentFenceTimeoutWarning = false;
};
class CountDownLatch {