SF: Fix thread safety for resync callback
The ResyncCallback for EventThreadConnection reads the HWComposer
pointer and the HWComposer::DisplayData map concurrently with writes
from the main thread. This CL factors that out into a getVsyncPeriod
function protected by mStateLock.
Bug: 74619554
Test: Boot and turn display on/off repeatedly
Change-Id: I9143a5d35b139d44d1e4e7509598b8568e7739aa
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index dc02666..1af1112 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -17,15 +17,16 @@
// #define LOG_NDEBUG 0
#define ATRACE_TAG ATRACE_TAG_GRAPHICS
-#include <stdint.h>
#include <sys/types.h>
-#include <algorithm>
#include <errno.h>
-#include <math.h>
-#include <mutex>
#include <dlfcn.h>
-#include <inttypes.h>
-#include <stdatomic.h>
+
+#include <algorithm>
+#include <cinttypes>
+#include <cmath>
+#include <cstdint>
+#include <functional>
+#include <mutex>
#include <optional>
#include <cutils/properties.h>
@@ -618,7 +619,7 @@
Mutex::Autolock _l(mStateLock);
- auto resyncCallback = makeResyncCallback();
+ auto resyncCallback = makeResyncCallback(std::bind(&SurfaceFlinger::getVsyncPeriod, this));
// start the EventThread
if (mUseScheduler) {
@@ -941,13 +942,15 @@
status_t SurfaceFlinger::setActiveConfigAsync(const sp<IBinder>& displayToken, int mode) {
ATRACE_NAME("setActiveConfigAsync");
- postMessageAsync(new LambdaMessage([=] { setActiveConfigInternal(displayToken, mode); }));
+ 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([&] { setActiveConfigInternal(displayToken, mode); }));
+ postMessageSync(new LambdaMessage(
+ [&]() NO_THREAD_SAFETY_ANALYSIS { setActiveConfigInternal(displayToken, mode); }));
return NO_ERROR;
}
@@ -988,7 +991,7 @@
getHwComposer().setActiveConfig(*displayId, mode);
ATRACE_INT("ActiveConfigMode", mode);
- resyncToHardwareVsync(true);
+ resyncToHardwareVsync(true, getVsyncPeriod());
}
status_t SurfaceFlinger::getDisplayColorModes(const sp<IBinder>& displayToken,
@@ -1168,7 +1171,7 @@
return;
}
- auto resyncCallback = makeResyncCallback();
+ auto resyncCallback = makeResyncCallback(std::bind(&SurfaceFlinger::getVsyncPeriod, this));
// TODO(akrulec): Part of the Injector should be refactored, so that it
// can be passed to Scheduler.
@@ -1241,7 +1244,10 @@
sp<IDisplayEventConnection> SurfaceFlinger::createDisplayEventConnection(
ISurfaceComposer::VsyncSource vsyncSource) {
- auto resyncCallback = makeResyncCallback();
+ auto resyncCallback = makeResyncCallback([this] {
+ Mutex::Autolock lock(mStateLock);
+ return getVsyncPeriod();
+ });
if (mUseScheduler) {
if (vsyncSource == eVsyncSourceSurfaceFlinger) {
@@ -1297,6 +1303,16 @@
} while (true);
}
+nsecs_t SurfaceFlinger::getVsyncPeriod() const {
+ const auto displayId = getInternalDisplayId();
+ if (!displayId || !getHwComposer().isConnected(*displayId)) {
+ return 0;
+ }
+
+ const auto config = getHwComposer().getActiveConfig(*displayId);
+ return config ? config->getVsyncPeriod() : 0;
+}
+
void SurfaceFlinger::enableHardwareVsync() {
Mutex::Autolock _l(mHWVsyncLock);
if (!mPrimaryHWVsyncEnabled && mHWVsyncAvailable) {
@@ -1306,7 +1322,7 @@
}
}
-void SurfaceFlinger::resyncToHardwareVsync(bool makeAvailable) {
+void SurfaceFlinger::resyncToHardwareVsync(bool makeAvailable, nsecs_t period) {
Mutex::Autolock _l(mHWVsyncLock);
if (makeAvailable) {
@@ -1321,14 +1337,10 @@
return;
}
- const auto displayId = getInternalDisplayId();
- if (!displayId || !getHwComposer().isConnected(*displayId)) {
+ if (period <= 0) {
return;
}
- const auto activeConfig = getHwComposer().getActiveConfig(*displayId);
- const nsecs_t period = activeConfig->getVsyncPeriod();
-
if (mUseScheduler) {
mScheduler->setVsyncPeriod(period);
} else {
@@ -1355,15 +1367,15 @@
}
}
-void SurfaceFlinger::VsyncState::resync() {
+void SurfaceFlinger::VsyncState::resync(const GetVsyncPeriod& getVsyncPeriod) {
static constexpr nsecs_t kIgnoreDelay = ms2ns(500);
- // No explicit locking is needed here since EventThread holds a lock while calling this method
const nsecs_t now = systemTime();
- if (now - lastResyncTime > kIgnoreDelay) {
- flinger.resyncToHardwareVsync(false);
+ const nsecs_t last = lastResyncTime.exchange(now);
+
+ if (now - last > kIgnoreDelay) {
+ flinger.resyncToHardwareVsync(false, getVsyncPeriod());
}
- lastResyncTime = now;
}
void SurfaceFlinger::onVsyncReceived(int32_t sequenceId, hwc2_display_t hwcDisplayId,
@@ -1563,9 +1575,8 @@
setPowerModeInternal(display, currentDisplayPowerMode);
// Reset the timing values to account for the period of the swapped in HWC
- const auto activeConfig = getHwComposer().getActiveConfig(*display->getId());
- const nsecs_t period = activeConfig->getVsyncPeriod();
- mAnimFrameTracker.setDisplayRefreshPeriod(period);
+ const nsecs_t vsyncPeriod = getVsyncPeriod();
+ mAnimFrameTracker.setDisplayRefreshPeriod(vsyncPeriod);
// The present fences returned from vr_hwc are not an accurate
// representation of vsync times.
@@ -1579,10 +1590,10 @@
// Use phase of 0 since phase is not known.
// Use latency of 0, which will snap to the ideal latency.
- DisplayStatInfo stats{0 /* vsyncTime */, period /* vsyncPeriod */};
+ DisplayStatInfo stats{0 /* vsyncTime */, vsyncPeriod};
setCompositorTimingSnapped(stats, 0);
- resyncToHardwareVsync(false);
+ resyncToHardwareVsync(false, vsyncPeriod);
mRepaintEverything = true;
setTransactionFlags(eDisplayTransactionNeeded);
@@ -4130,8 +4141,11 @@
// ---------------------------------------------------------------------------
void SurfaceFlinger::onInitializeDisplays() {
- const auto displayToken = getInternalDisplayToken();
- if (!displayToken) return;
+ const auto display = getDefaultDisplayDeviceLocked();
+ if (!display) return;
+
+ const sp<IBinder> token = display->getDisplayToken().promote();
+ LOG_ALWAYS_FATAL_IF(token == nullptr);
// reset screen orientation and use primary layer stack
Vector<ComposerState> state;
@@ -4139,7 +4153,7 @@
DisplayState d;
d.what = DisplayState::eDisplayProjectionChanged |
DisplayState::eLayerStackChanged;
- d.token = displayToken;
+ d.token = token;
d.layerStack = 0;
d.orientation = DisplayState::eOrientationDefault;
d.frame.makeInvalid();
@@ -4149,24 +4163,21 @@
displays.add(d);
setTransactionState(state, displays, 0, nullptr, mInputWindowCommands);
- const auto display = getDisplayDevice(displayToken);
- if (!display) return;
-
setPowerModeInternal(display, HWC_POWER_MODE_NORMAL);
- const auto activeConfig = getHwComposer().getActiveConfig(*display->getId());
- const nsecs_t period = activeConfig->getVsyncPeriod();
- mAnimFrameTracker.setDisplayRefreshPeriod(period);
+ const nsecs_t vsyncPeriod = getVsyncPeriod();
+ mAnimFrameTracker.setDisplayRefreshPeriod(vsyncPeriod);
// Use phase of 0 since phase is not known.
// Use latency of 0, which will snap to the ideal latency.
- DisplayStatInfo stats{0 /* vsyncTime */, period /* vsyncPeriod */};
+ DisplayStatInfo stats{0 /* vsyncTime */, vsyncPeriod};
setCompositorTimingSnapped(stats, 0);
}
void SurfaceFlinger::initializeDisplays() {
// Async since we may be called from the main thread.
- postMessageAsync(new LambdaMessage([this] { onInitializeDisplays(); }));
+ postMessageAsync(
+ new LambdaMessage([this]() NO_THREAD_SAFETY_ANALYSIS { onInitializeDisplays(); }));
}
void SurfaceFlinger::setPowerModeInternal(const sp<DisplayDevice>& display, int mode) {
@@ -4200,7 +4211,7 @@
} else {
mEventThread->onScreenAcquired();
}
- resyncToHardwareVsync(true);
+ resyncToHardwareVsync(true, getVsyncPeriod());
}
mVisibleRegionsDirty = true;
@@ -4245,7 +4256,7 @@
} else {
mEventThread->onScreenAcquired();
}
- resyncToHardwareVsync(true);
+ resyncToHardwareVsync(true, getVsyncPeriod());
}
} else if (mode == HWC_POWER_MODE_DOZE_SUSPEND) {
// Leave display going to doze
@@ -4275,7 +4286,7 @@
}
void SurfaceFlinger::setPowerMode(const sp<IBinder>& displayToken, int mode) {
- postMessageSync(new LambdaMessage([&] {
+ postMessageSync(new LambdaMessage([&]() NO_THREAD_SAFETY_ANALYSIS {
const auto display = getDisplayDevice(displayToken);
if (!display) {
ALOGE("Attempt to set power mode %d for invalid display token %p", mode,
@@ -4448,12 +4459,7 @@
index++;
}
- if (const auto displayId = getInternalDisplayId();
- displayId && getHwComposer().isConnected(*displayId)) {
- const auto activeConfig = getHwComposer().getActiveConfig(*displayId);
- const nsecs_t period = activeConfig->getVsyncPeriod();
- StringAppendF(&result, "%" PRId64 "\n", period);
- }
+ StringAppendF(&result, "%" PRId64 "\n", getVsyncPeriod());
if (name.isEmpty()) {
mAnimFrameTracker.dumpStats(result);
@@ -4754,22 +4760,16 @@
const auto [sfEarlyOffset, appEarlyOffset] = mVsyncModulator.getEarlyOffsets();
const auto [sfEarlyGlOffset, appEarlyGlOffset] = mVsyncModulator.getEarlyGlOffsets();
- if (const auto displayId = getInternalDisplayId();
- displayId && getHwComposer().isConnected(*displayId)) {
- const auto activeConfig = getHwComposer().getActiveConfig(*displayId);
- StringAppendF(&result,
- "Display %s: app phase %" PRId64 " ns, "
- "sf phase %" PRId64 " ns, "
- "early app phase %" PRId64 " ns, "
- "early sf phase %" PRId64 " ns, "
- "early app gl phase %" PRId64 " ns, "
- "early sf gl phase %" PRId64 " ns, "
- "present offset %" PRId64 " ns (refresh %" PRId64 " ns)",
- to_string(*displayId).c_str(), vsyncPhaseOffsetNs, sfVsyncPhaseOffsetNs,
- appEarlyOffset, sfEarlyOffset, appEarlyGlOffset, sfEarlyGlOffset,
- dispSyncPresentTimeOffset, activeConfig->getVsyncPeriod());
- }
- result.append("\n");
+ StringAppendF(&result,
+ "app phase %" PRId64 " ns, "
+ "sf phase %" PRId64 " ns, "
+ "early app phase %" PRId64 " ns, "
+ "early sf phase %" PRId64 " ns, "
+ "early app gl phase %" PRId64 " ns, "
+ "early sf gl phase %" PRId64 " ns, "
+ "present offset %" PRId64 " ns (refresh %" PRId64 " ns)\n",
+ vsyncPhaseOffsetNs, sfVsyncPhaseOffsetNs, appEarlyOffset, sfEarlyOffset,
+ appEarlyGlOffset, sfEarlyGlOffset, dispSyncPresentTimeOffset, getVsyncPeriod());
// Dump static screen stats
result.append("\n");
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index c92874b..a4bd3e9 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -17,14 +17,13 @@
#ifndef ANDROID_SURFACE_FLINGER_H
#define ANDROID_SURFACE_FLINGER_H
-#include <memory>
-#include <stdint.h>
#include <sys/types.h>
/*
* NOTE: Make sure this file doesn't include anything from <gl/ > or <gl2/ >
*/
+#include <android-base/thread_annotations.h>
#include <cutils/atomic.h>
#include <cutils/compiler.h>
#include <gui/BufferQueue.h>
@@ -66,7 +65,10 @@
#include "SurfaceTracing.h"
#include "TransactionCompletedThread.h"
+#include <atomic>
+#include <cstdint>
#include <map>
+#include <memory>
#include <mutex>
#include <queue>
#include <set>
@@ -489,13 +491,13 @@
void signalRefresh();
// called on the main thread in response to initializeDisplays()
- void onInitializeDisplays();
+ void onInitializeDisplays() REQUIRES(mStateLock);
// setActiveConfigInternal() posted on a main thread for async execution
status_t setActiveConfigAsync(const sp<IBinder>& displayToken, int mode);
// called on the main thread in response to setActiveConfig()
- void setActiveConfigInternal(const sp<IBinder>& displayToken, int mode);
+ void setActiveConfigInternal(const sp<IBinder>& displayToken, int mode) REQUIRES(mStateLock);
// called on the main thread in response to setPowerMode()
- void setPowerModeInternal(const sp<DisplayDevice>& display, int mode);
+ void setPowerModeInternal(const sp<DisplayDevice>& display, int mode) REQUIRES(mStateLock);
// Called on the main thread in response to setActiveColorMode()
void setActiveColorModeInternal(const sp<DisplayDevice>& display, ui::ColorMode colorMode,
@@ -746,31 +748,34 @@
/* ------------------------------------------------------------------------
* VSync
*/
+ nsecs_t getVsyncPeriod() const REQUIRES(mStateLock);
void enableHardwareVsync();
- void resyncToHardwareVsync(bool makeAvailable);
+ void resyncToHardwareVsync(bool makeAvailable, nsecs_t period);
void disableHardwareVsync(bool makeUnavailable);
// Sets the refresh rate to newFps by switching active configs, if they are available for
// the desired refresh rate.
void setRefreshRateTo(float newFps);
+ using GetVsyncPeriod = std::function<nsecs_t()>;
+
// Stores per-display state about VSYNC.
struct VsyncState {
explicit VsyncState(SurfaceFlinger& flinger) : flinger(flinger) {}
- void resync();
+ void resync(const GetVsyncPeriod&);
SurfaceFlinger& flinger;
- nsecs_t lastResyncTime = 0;
+ std::atomic<nsecs_t> lastResyncTime = 0;
};
const std::shared_ptr<VsyncState> mPrimaryVsyncState{std::make_shared<VsyncState>(*this)};
- auto makeResyncCallback() {
+ auto makeResyncCallback(GetVsyncPeriod&& getVsyncPeriod) {
std::weak_ptr<VsyncState> ptr = mPrimaryVsyncState;
- return [ptr]() {
+ return [ptr, getVsyncPeriod = std::move(getVsyncPeriod)]() {
if (const auto vsync = ptr.lock()) {
- vsync->resync();
+ vsync->resync(getVsyncPeriod);
}
};
}
@@ -820,9 +825,11 @@
}
void listLayersLocked(const Vector<String16>& args, size_t& index, std::string& result) const;
- void dumpStatsLocked(const Vector<String16>& args, size_t& index, std::string& result) const;
+ void dumpStatsLocked(const Vector<String16>& args, size_t& index, std::string& result) const
+ REQUIRES(mStateLock);
void clearStatsLocked(const Vector<String16>& args, size_t& index, std::string& result);
- void dumpAllLocked(const Vector<String16>& args, size_t& index, std::string& result) const;
+ void dumpAllLocked(const Vector<String16>& args, size_t& index, std::string& result) const
+ REQUIRES(mStateLock);
bool startDdmConnection();
void appendSfConfigString(std::string& result) const;
diff --git a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
index 9ff5e8d..15a8c5a 100644
--- a/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
+++ b/services/surfaceflinger/tests/unittests/TestableSurfaceFlinger.h
@@ -235,9 +235,14 @@
auto setDisplayStateLocked(const DisplayState& s) { return mFlinger->setDisplayStateLocked(s); }
- auto onInitializeDisplays() { return mFlinger->onInitializeDisplays(); }
+ // Allow reading display state without locking, as if called on the SF main thread.
+ auto onInitializeDisplays() NO_THREAD_SAFETY_ANALYSIS {
+ return mFlinger->onInitializeDisplays();
+ }
- auto setPowerModeInternal(const sp<DisplayDevice>& display, int mode) {
+ // Allow reading display state without locking, as if called on the SF main thread.
+ auto setPowerModeInternal(const sp<DisplayDevice>& display,
+ int mode) NO_THREAD_SAFETY_ANALYSIS {
return mFlinger->setPowerModeInternal(display, mode);
}