[SurfaceFlinger] Resolve deadlock in SurfaceTracing.
SurfaceTracing cannot acquire mStateLock while mDrawingStateLock is
held. SurfaceTracing only needs to acquire mStateLock for getting the
default DisplayDevice for getting a layer's HWC composition type. As a
workaround, grab the DisplayDevice ahead of time.
Bug: 151108871
Test: builds
Change-Id: I84a76694e9890242c666ec5e3eb04d4114f8240a
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 29fe5d9..3052819 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4482,12 +4482,11 @@
result.append("\n");
}
-LayersProto SurfaceFlinger::dumpDrawingStateProto(uint32_t traceFlags) const {
- Mutex::Autolock _l(mStateLock);
- const auto device = getDefaultDisplayDeviceLocked();
+LayersProto SurfaceFlinger::dumpDrawingStateProto(
+ uint32_t traceFlags, const sp<const DisplayDevice>& displayDevice) const {
LayersProto layersProto;
for (const sp<Layer>& layer : mDrawingState.layersSortedByZ) {
- layer->writeToProto(layersProto, traceFlags, device);
+ layer->writeToProto(layersProto, traceFlags, displayDevice);
}
return layersProto;
@@ -4519,7 +4518,10 @@
LayersProto SurfaceFlinger::dumpProtoFromMainThread(uint32_t traceFlags) {
LayersProto layersProto;
- postMessageSync(new LambdaMessage([&]() { layersProto = dumpDrawingStateProto(traceFlags); }));
+ postMessageSync(new LambdaMessage([&]() {
+ const auto& displayDevice = getDefaultDisplayDeviceLocked();
+ layersProto = dumpDrawingStateProto(traceFlags, displayDevice);
+ }));
return layersProto;
}
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index e6b91e6..ba265ad 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -923,7 +923,8 @@
void dumpDisplayIdentificationData(std::string& result) const;
void dumpRawDisplayIdentificationData(const DumpArgs&, std::string& result) const;
void dumpWideColorInfo(std::string& result) const;
- LayersProto dumpDrawingStateProto(uint32_t traceFlags = SurfaceTracing::TRACE_ALL) const;
+ LayersProto dumpDrawingStateProto(uint32_t traceFlags = SurfaceTracing::TRACE_ALL,
+ const sp<const DisplayDevice>& displayDevice = nullptr) const;
void dumpOffscreenLayersProto(LayersProto& layersProto,
uint32_t traceFlags = SurfaceTracing::TRACE_ALL) const;
// Dumps state from HW Composer
diff --git a/services/surfaceflinger/SurfaceTracing.cpp b/services/surfaceflinger/SurfaceTracing.cpp
index c5556ec..20c8d7a 100644
--- a/services/surfaceflinger/SurfaceTracing.cpp
+++ b/services/surfaceflinger/SurfaceTracing.cpp
@@ -45,19 +45,21 @@
}
void SurfaceTracing::addFirstEntry() {
+ const auto displayDevice = mFlinger.getDefaultDisplayDevice();
LayersTraceProto entry;
{
std::scoped_lock lock(mSfLock);
- entry = traceLayersLocked("tracing.enable");
+ entry = traceLayersLocked("tracing.enable", displayDevice);
}
addTraceToBuffer(entry);
}
LayersTraceProto SurfaceTracing::traceWhenNotified() {
+ const auto displayDevice = mFlinger.getDefaultDisplayDevice();
std::unique_lock<std::mutex> lock(mSfLock);
mCanStartTrace.wait(lock);
android::base::ScopedLockAssertion assumeLock(mSfLock);
- LayersTraceProto entry = traceLayersLocked(mWhere);
+ LayersTraceProto entry = traceLayersLocked(mWhere, displayDevice);
lock.unlock();
return entry;
}
@@ -160,13 +162,14 @@
mTraceFlags = flags;
}
-LayersTraceProto SurfaceTracing::traceLayersLocked(const char* where) {
+LayersTraceProto SurfaceTracing::traceLayersLocked(const char* where,
+ const sp<const DisplayDevice>& displayDevice) {
ATRACE_CALL();
LayersTraceProto entry;
entry.set_elapsed_realtime_nanos(elapsedRealtimeNano());
entry.set_where(where);
- LayersProto layers(mFlinger.dumpDrawingStateProto(mTraceFlags));
+ LayersProto layers(mFlinger.dumpDrawingStateProto(mTraceFlags, displayDevice));
mFlinger.dumpOffscreenLayersProto(layers);
entry.mutable_layers()->Swap(&layers);
diff --git a/services/surfaceflinger/SurfaceTracing.h b/services/surfaceflinger/SurfaceTracing.h
index 3c24881..4b9f777 100644
--- a/services/surfaceflinger/SurfaceTracing.h
+++ b/services/surfaceflinger/SurfaceTracing.h
@@ -16,17 +16,19 @@
#pragma once
+#include <android-base/thread_annotations.h>
#include <layerproto/LayerProtoHeader.h>
#include <utils/Errors.h>
#include <utils/StrongPointer.h>
-#include <android-base/thread_annotations.h>
#include <condition_variable>
#include <memory>
#include <mutex>
#include <queue>
#include <thread>
+#include "DisplayDevice.h"
+
using namespace android::surfaceflinger;
namespace android {
@@ -85,13 +87,15 @@
void mainLoop();
void addFirstEntry();
LayersTraceProto traceWhenNotified();
- LayersTraceProto traceLayersLocked(const char* where) REQUIRES(mSfLock);
+ LayersTraceProto traceLayersLocked(const char* where,
+ const sp<const DisplayDevice>& displayDevice)
+ REQUIRES(mSfLock);
// Returns true if trace is enabled.
bool addTraceToBuffer(LayersTraceProto& entry);
void writeProtoFileLocked() REQUIRES(mTraceLock);
- const SurfaceFlinger& mFlinger;
+ SurfaceFlinger& mFlinger;
status_t mLastErr = NO_ERROR;
std::thread mThread;
std::condition_variable mCanStartTrace;