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
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 1a64f69..e6cf1e9 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -120,6 +120,7 @@
using namespace android::hardware::configstore;
using namespace android::hardware::configstore::V1_0;
using namespace android::sysprop;
+
using base::StringAppendF;
using ui::ColorMode;
using ui::Dataspace;
@@ -127,6 +128,8 @@
using ui::Hdr;
using ui::RenderIntent;
+using RefreshRateType = scheduler::RefreshRateConfigs::RefreshRateType;
+
namespace {
#pragma clang diagnostic push
@@ -211,6 +214,9 @@
constexpr float kSrgbWhiteY = 1.0000f;
constexpr float kSrgbWhiteZ = 1.0891f;
+constexpr float kDefaultRefreshRate = 60.f;
+constexpr float kPerformanceRefreshRate = 90.f;
+
// ---------------------------------------------------------------------------
int64_t SurfaceFlinger::dispSyncPresentTimeOffset;
bool SurfaceFlinger::useHwcForRgbToYuv;
@@ -627,13 +633,17 @@
mPhaseOffsets->setRefreshRateType(
scheduler::RefreshRateConfigs::RefreshRateType::PERFORMANCE);
+ auto resetIdleTimerCallback =
+ std::bind(&SurfaceFlinger::setRefreshRateTo, this, RefreshRateType::PERFORMANCE);
+
mAppConnectionHandle =
mScheduler->createConnection("appConnection", mPhaseOffsets->getCurrentAppOffset(),
- resyncCallback,
+ resyncCallback, resetIdleTimerCallback,
impl::EventThread::InterceptVSyncsCallback());
mSfConnectionHandle =
mScheduler->createConnection("sfConnection", mPhaseOffsets->getCurrentSfOffset(),
- resyncCallback, [this](nsecs_t timestamp) {
+ resyncCallback, resetIdleTimerCallback,
+ [this](nsecs_t timestamp) {
mInterceptor->saveVSyncEvent(timestamp);
});
@@ -731,20 +741,11 @@
}
if (mUseScheduler) {
- mScheduler->setExpiredIdleTimerCallback([this]() {
- mPhaseOffsets->setRefreshRateType(
- scheduler::RefreshRateConfigs::RefreshRateType::DEFAULT);
- const auto [early, gl, late] = mPhaseOffsets->getCurrentOffsets();
- mVsyncModulator.setPhaseOffsets(early, gl, late);
- setRefreshRateTo(60.f /* fps */);
+ mScheduler->setExpiredIdleTimerCallback([this] {
+ Mutex::Autolock lock(mStateLock);
+ setRefreshRateTo(RefreshRateType::DEFAULT);
});
- mScheduler->setResetIdleTimerCallback([this]() {
- mPhaseOffsets->setRefreshRateType(
- scheduler::RefreshRateConfigs::RefreshRateType::PERFORMANCE);
- const auto [early, gl, late] = mPhaseOffsets->getCurrentOffsets();
- mVsyncModulator.setPhaseOffsets(early, gl, late);
- setRefreshRateTo(90.f /* fps */);
- });
+
mRefreshRateStats =
std::make_unique<scheduler::RefreshRateStats>(getHwComposer().getConfigs(
*display->getId()),
@@ -956,13 +957,6 @@
return display->getActiveConfig();
}
-status_t SurfaceFlinger::setActiveConfigAsync(const sp<IBinder>& displayToken, int mode) {
- ATRACE_NAME("setActiveConfigAsync");
- postMessageAsync(new LambdaMessage(
- [=]() NO_THREAD_SAFETY_ANALYSIS { setActiveConfigInternal(displayToken, mode); }));
- return NO_ERROR;
-}
-
status_t SurfaceFlinger::setActiveConfig(const sp<IBinder>& displayToken, int mode) {
ATRACE_NAME("setActiveConfigSync");
postMessageSync(new LambdaMessage(
@@ -1269,16 +1263,21 @@
});
if (mUseScheduler) {
- if (vsyncSource == eVsyncSourceSurfaceFlinger) {
- return mScheduler->createDisplayEventConnection(mSfConnectionHandle, resyncCallback);
- } else {
- return mScheduler->createDisplayEventConnection(mAppConnectionHandle, resyncCallback);
- }
+ auto resetIdleTimerCallback = [this] {
+ Mutex::Autolock lock(mStateLock);
+ setRefreshRateTo(RefreshRateType::PERFORMANCE);
+ };
+
+ const auto& handle = vsyncSource == eVsyncSourceSurfaceFlinger ? mSfConnectionHandle
+ : mAppConnectionHandle;
+
+ return mScheduler->createDisplayEventConnection(handle, std::move(resyncCallback),
+ std::move(resetIdleTimerCallback));
} else {
if (vsyncSource == eVsyncSourceSurfaceFlinger) {
- return mSFEventThread->createEventConnection(resyncCallback);
+ return mSFEventThread->createEventConnection(resyncCallback, ResetIdleTimerCallback());
} else {
- return mEventThread->createEventConnection(resyncCallback);
+ return mEventThread->createEventConnection(resyncCallback, ResetIdleTimerCallback());
}
}
}
@@ -1440,12 +1439,16 @@
*compositorTiming = getBE().mCompositorTiming;
}
-// TODO(b/123715322): Fix thread safety.
-void SurfaceFlinger::setRefreshRateTo(float newFps) NO_THREAD_SAFETY_ANALYSIS {
- const auto display = getDefaultDisplayDeviceLocked();
- if (!display || mBootStage != BootStage::FINISHED) {
+void SurfaceFlinger::setRefreshRateTo(RefreshRateType refreshRate) {
+ mPhaseOffsets->setRefreshRateType(refreshRate);
+
+ const auto [early, gl, late] = mPhaseOffsets->getCurrentOffsets();
+ mVsyncModulator.setPhaseOffsets(early, gl, late);
+
+ if (mBootStage != BootStage::FINISHED) {
return;
}
+
// TODO(b/113612090): There should be a message queue flush here. Because this esentially
// runs on a mainthread, we cannot call postMessageSync. This can be resolved in a better
// manner, once the setActiveConfig is synchronous, and is executed at a known time in a
@@ -1456,14 +1459,20 @@
if (currentVsyncPeriod == 0) {
return;
}
+
// TODO(b/113612090): Consider having an enum value for correct refresh rates, rather than
// floating numbers.
const float currentFps = 1e9 / currentVsyncPeriod;
+ const float newFps = refreshRate == RefreshRateType::PERFORMANCE ? kPerformanceRefreshRate
+ : kDefaultRefreshRate;
if (std::abs(currentFps - newFps) <= 1) {
return;
}
- auto configs = getHwComposer().getConfigs(*display->getId());
+ const auto displayId = getInternalDisplayIdLocked();
+ LOG_ALWAYS_FATAL_IF(!displayId);
+
+ auto configs = getHwComposer().getConfigs(*displayId);
for (int i = 0; i < configs.size(); i++) {
const nsecs_t vsyncPeriod = configs.at(i)->getVsyncPeriod();
if (vsyncPeriod == 0) {
@@ -1473,12 +1482,7 @@
// TODO(b/113612090): There should be a better way at determining which config
// has the right refresh rate.
if (std::abs(fps - newFps) <= 1) {
- const sp<IBinder> token = display->getDisplayToken().promote();
- LOG_ALWAYS_FATAL_IF(token == nullptr);
-
- // This is posted in async function to avoid deadlock when getDisplayDevice
- // requires mStateLock.
- setActiveConfigAsync(token, i);
+ setActiveConfigInternal(getInternalDisplayTokenLocked(), i);
ATRACE_INT("FPS", newFps);
}
}
@@ -5396,8 +5400,8 @@
DisplayRenderArea renderArea(display, sourceCrop, reqWidth, reqHeight, reqDataspace,
renderAreaRotation);
- auto traverseLayers = std::bind(std::mem_fn(&SurfaceFlinger::traverseLayersInDisplay), this,
- display, std::placeholders::_1);
+ auto traverseLayers = std::bind(&SurfaceFlinger::traverseLayersInDisplay, this, display,
+ std::placeholders::_1);
return captureScreenCommon(renderArea, traverseLayers, outBuffer, reqPixelFormat,
useIdentityTransform);
}