Fix locking issues with proto dumps
Proto dumps are generated from:
- binder threads when generating bugreports or triggering dumpstate
- main thread when mLayerStats is enabled
- tracing thread when winscope tracing is enabled.
The binder thread reads current state while the other threads reads drawing state.
The writeToProto function accesses a mix of current and drawing states. mPendingState should
only be accessed with the mStateLock held and the visible regions should be read from the main
or tracing threads. This causes some invalid access issues.
To make the locking requirements clear, this change
1. moves drawing specific data to a new function
2. copies mPendingState so we can dump the copy safely in main thread
3. dumps drawing data from binder threads by posting a message onto the main thread
Bug: 138318680
Test: adb shell dumpsys SurfaceFlinger, winscope
Change-Id: I8bb93e9b9f81faec59585b770eb7ba0fbcd9b51b
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 8bf6b99..e8b39cc 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4578,18 +4578,22 @@
if (const auto it = dumpers.find(flag); it != dumpers.end()) {
(it->second)(args, asProto, result);
- } else {
- if (asProto) {
- LayersProto layersProto = dumpProtoInfo(LayerVector::StateSet::Current);
- result.append(layersProto.SerializeAsString().c_str(), layersProto.ByteSize());
- } else {
- dumpAllLocked(args, result);
- }
+ } else if (!asProto) {
+ dumpAllLocked(args, result);
}
if (locked) {
mStateLock.unlock();
}
+
+ LayersProto layersProto = dumpProtoFromMainThread();
+ if (asProto) {
+ result.append(layersProto.SerializeAsString().c_str(), layersProto.ByteSize());
+ } else {
+ auto layerTree = LayerProtoParser::generateLayerTree(layersProto);
+ result.append(LayerProtoParser::layerTreeToString(layerTree));
+ result.append("\n");
+ }
}
write(fd, result.c_str(), result.size());
return NO_ERROR;
@@ -4830,19 +4834,23 @@
result.append("\n");
}
-LayersProto SurfaceFlinger::dumpProtoInfo(LayerVector::StateSet stateSet,
- uint32_t traceFlags) const {
+LayersProto SurfaceFlinger::dumpDrawingStateProto(uint32_t traceFlags) const {
LayersProto layersProto;
- const bool useDrawing = stateSet == LayerVector::StateSet::Drawing;
- const State& state = useDrawing ? mDrawingState : mCurrentState;
- state.traverseInZOrder([&](Layer* layer) {
+ mDrawingState.traverseInZOrder([&](Layer* layer) {
LayerProto* layerProto = layersProto.add_layers();
- layer->writeToProto(layerProto, stateSet, traceFlags);
+ layer->writeToProtoDrawingState(layerProto, traceFlags);
+ layer->writeToProtoCommonState(layerProto, LayerVector::StateSet::Drawing, traceFlags);
});
return layersProto;
}
+LayersProto SurfaceFlinger::dumpProtoFromMainThread(uint32_t traceFlags) {
+ LayersProto layersProto;
+ postMessageSync(new LambdaMessage([&]() { layersProto = dumpDrawingStateProto(traceFlags); }));
+ return layersProto;
+}
+
LayersProto SurfaceFlinger::dumpVisibleLayersProtoInfo(
const sp<DisplayDevice>& displayDevice) const {
LayersProto layersProto;
@@ -4863,7 +4871,7 @@
mDrawingState.traverseInZOrder([&](Layer* layer) {
if (!layer->visibleRegion.isEmpty() && !display->getOutputLayersOrderedByZ().empty()) {
LayerProto* layerProto = layersProto.add_layers();
- layer->writeToProto(layerProto, displayDevice);
+ layer->writeToProtoCompositionState(layerProto, displayDevice);
}
});
@@ -4928,13 +4936,6 @@
colorizer.reset(result);
{
- LayersProto layersProto = dumpProtoInfo(LayerVector::StateSet::Current);
- auto layerTree = LayerProtoParser::generateLayerTree(layersProto);
- result.append(LayerProtoParser::layerTreeToString(layerTree));
- result.append("\n");
- }
-
- {
StringAppendF(&result, "Composition layers\n");
mDrawingState.traverseInZOrder([&](Layer* layer) {
auto compositionLayer = layer->getCompositionLayer();