commit 708ebfbcfabb8f28cb88c5b39b099424e894530e
author Ady Abraham <adyabr@google.com> Thu Nov 14 14:42:49 2024 -0800
committer Ady Abraham <adyabr@google.com> Thu Nov 14 22:46:31 2024 +0000
tree 8cde48e9e669cd418f20110dc3899fc1f4011046
parent 7a3c56f80f101c0c4500f574fc44feb4fbb23de9

SF: add a backdoor to introduce a janky frame to HWC

Bug: 346503493
Test: adb shell service call SurfaceFlinger 1046 i32 3Test: adb root && adb shell service call SurfaceFlinger 1046 i32 3
Flag: EXEMPT bugfix
Change-Id: Ic4a837ef06aca40a24db9c1121e19e3e1a1e0d80

services/surfaceflinger/Scheduler/Scheduler.cpp

diff --git a/services/surfaceflinger/Scheduler/Scheduler.cpp b/services/surfaceflinger/Scheduler/Scheduler.cpp
index 8c587a9..2875650 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.cpp
+++ b/services/surfaceflinger/Scheduler/Scheduler.cpp
@@ -203,12 +203,16 @@
 
 void Scheduler::onFrameSignal(ICompositor& compositor, VsyncId vsyncId,
                               TimePoint expectedVsyncTime) {
+    const auto debugPresentDelay = mDebugPresentDelay.load();
+    mDebugPresentDelay.store(std::nullopt);
+
     const FrameTargeter::BeginFrameArgs beginFrameArgs =
             {.frameBeginTime = SchedulerClock::now(),
              .vsyncId = vsyncId,
              .expectedVsyncTime = expectedVsyncTime,
              .sfWorkDuration = mVsyncModulator->getVsyncConfig().sfWorkDuration,
-             .hwcMinWorkDuration = mVsyncConfiguration->getCurrentConfigs().hwcMinWorkDuration};
+             .hwcMinWorkDuration = mVsyncConfiguration->getCurrentConfigs().hwcMinWorkDuration,
+             .debugPresentTimeDelay = debugPresentDelay};
 
     ftl::NonNull<const Display*> pacesetterPtr = pacesetterPtrLocked();
     pacesetterPtr->targeterPtr->beginFrame(beginFrameArgs, *pacesetterPtr->schedulePtr);

services/surfaceflinger/Scheduler/Scheduler.h

diff --git a/services/surfaceflinger/Scheduler/Scheduler.h b/services/surfaceflinger/Scheduler/Scheduler.h
index 8340880..61c68a9 100644
--- a/services/surfaceflinger/Scheduler/Scheduler.h
+++ b/services/surfaceflinger/Scheduler/Scheduler.h
@@ -337,6 +337,8 @@
     // recovery should begin.
     void addBufferStuffedUids(BufferStuffingMap bufferStuffedUids);
 
+    void setDebugPresentDelay(TimePoint delay) { mDebugPresentDelay = delay; }
+
 private:
     friend class TestableScheduler;
 
@@ -602,6 +604,8 @@
 
     FrameRateOverrideMappings mFrameRateOverrideMappings;
     SmallAreaDetectionAllowMappings mSmallAreaDetectionAllowMappings;
+
+    std::atomic<std::optional<TimePoint>> mDebugPresentDelay;
 };
 
 } // namespace scheduler

services/surfaceflinger/Scheduler/include/scheduler/FrameTargeter.h

diff --git a/services/surfaceflinger/Scheduler/include/scheduler/FrameTargeter.h b/services/surfaceflinger/Scheduler/include/scheduler/FrameTargeter.h
index 2185bb0..813d4de 100644
--- a/services/surfaceflinger/Scheduler/include/scheduler/FrameTargeter.h
+++ b/services/surfaceflinger/Scheduler/include/scheduler/FrameTargeter.h
@@ -53,6 +53,8 @@
 
     TimePoint expectedPresentTime() const { return mExpectedPresentTime; }
 
+    std::optional<TimePoint> debugPresentDelay() const { return mDebugPresentTimeDelay; }
+
     std::optional<TimePoint> earliestPresentTime() const { return mEarliestPresentTime; }
 
     // Equivalent to `expectedSignaledPresentFence` unless running N VSYNCs ahead.
@@ -84,6 +86,7 @@
     TimePoint mFrameBeginTime;
     TimePoint mExpectedPresentTime;
     std::optional<TimePoint> mEarliestPresentTime;
+    std::optional<TimePoint> mDebugPresentTimeDelay;
 
     TracedOrdinal<bool> mFramePending;
     TracedOrdinal<bool> mFrameMissed;
@@ -135,6 +138,7 @@
         TimePoint expectedVsyncTime;
         Duration sfWorkDuration;
         Duration hwcMinWorkDuration;
+        std::optional<TimePoint> debugPresentTimeDelay; // used to introduce jank for testing
     };
 
     void beginFrame(const BeginFrameArgs&, const IVsyncSource&);

services/surfaceflinger/Scheduler/src/FrameTargeter.cpp

diff --git a/services/surfaceflinger/Scheduler/src/FrameTargeter.cpp b/services/surfaceflinger/Scheduler/src/FrameTargeter.cpp
index 3ee1e54..4f16130 100644
--- a/services/surfaceflinger/Scheduler/src/FrameTargeter.cpp
+++ b/services/surfaceflinger/Scheduler/src/FrameTargeter.cpp
@@ -86,6 +86,7 @@
                                IsFencePendingFuncPtr isFencePendingFuncPtr) {
     mVsyncId = args.vsyncId;
     mFrameBeginTime = args.frameBeginTime;
+    mDebugPresentTimeDelay = args.debugPresentTimeDelay;
 
     // The `expectedVsyncTime`, which was predicted when this frame was scheduled, is normally in
     // the future relative to `frameBeginTime`, but may not be for delayed frames. Adjust