[sf] provide a unique id for snapshots
Input and layer tracing relies on the fact that all layers
have a unique id. Because mirror layers are no longer
implemented by duplicating layers, we can have multiple
snapshots with the same id. To fix this, provide a unique
id that can be used by consumers who require them.
Test: atest FlickerTest
Bug: 238781169
Change-Id: Ibe54154b6e14f72bfe73a15faa0e7e0d19293e36
diff --git a/services/surfaceflinger/FrontEnd/LayerSnapshot.cpp b/services/surfaceflinger/FrontEnd/LayerSnapshot.cpp
index 85b00d7..8a45093 100644
--- a/services/surfaceflinger/FrontEnd/LayerSnapshot.cpp
+++ b/services/surfaceflinger/FrontEnd/LayerSnapshot.cpp
@@ -27,12 +27,16 @@
LayerSnapshot::LayerSnapshot(const RequestedLayerState& state,
const LayerHierarchy::TraversalPath& path)
: path(path) {
+ static uint32_t sUniqueSequenceId = 0;
+ // Provide a unique id for clones otherwise keeping using the sequence id.
+ // The seq id can still be useful for debugging if its available.
+ uniqueSequence = (path.isClone()) ? sUniqueSequenceId++ : state.id;
sequence = static_cast<int32_t>(state.id);
name = state.name;
textureName = state.textureName;
premultipliedAlpha = state.premultipliedAlpha;
inputInfo.name = state.name;
- inputInfo.id = static_cast<int32_t>(state.id);
+ inputInfo.id = static_cast<int32_t>(uniqueSequence);
inputInfo.ownerUid = static_cast<int32_t>(state.ownerUid);
inputInfo.ownerPid = state.ownerPid;
changes = RequestedLayerState::Changes::Created;
diff --git a/services/surfaceflinger/FrontEnd/LayerSnapshot.h b/services/surfaceflinger/FrontEnd/LayerSnapshot.h
index 07aa122..e069a63 100644
--- a/services/surfaceflinger/FrontEnd/LayerSnapshot.h
+++ b/services/surfaceflinger/FrontEnd/LayerSnapshot.h
@@ -57,6 +57,12 @@
bool isHiddenByPolicyFromParent = false;
bool isHiddenByPolicyFromRelativeParent = false;
ftl::Flags<RequestedLayerState::Changes> changes;
+ // Some consumers of this snapshot (input, layer traces) rely on each snapshot to be unique.
+ // For mirrored layers, snapshots will have the same sequence so this unique id provides
+ // an alternative identifier when needed.
+ uint32_t uniqueSequence;
+ // Layer id used to create this snapshot. Multiple snapshots will have the same sequence if they
+ // generated from the same layer, for example when mirroring.
int32_t sequence;
std::string name;
uint32_t textureName;
diff --git a/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp b/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
index db6e716..344dab4 100644
--- a/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
+++ b/services/surfaceflinger/FrontEnd/LayerSnapshotBuilder.cpp
@@ -957,7 +957,7 @@
}
snapshot.inputInfo.name = requested.name;
- snapshot.inputInfo.id = static_cast<int32_t>(requested.id);
+ snapshot.inputInfo.id = static_cast<int32_t>(snapshot.uniqueSequence);
snapshot.inputInfo.ownerUid = static_cast<int32_t>(requested.ownerUid);
snapshot.inputInfo.ownerPid = requested.ownerPid;
snapshot.inputInfo.displayId = static_cast<int32_t>(snapshot.outputFilter.layerStack.id);