commit e450fb5c322249a2b421f99161e5476015b20b0c
author Robert Carr <racarr@google.com> Fri Jun 11 13:21:09 2021 -0700
committer Rob Carr <racarr@google.com> Fri Jun 18 23:14:46 2021 +0000
tree 47ba1520320c87c44273e3d618102bf9d6119c50
parent 26953ee25d470a7f54d3b789ab57a1f304327a6a

Factor our mChildrenChanged from doTransaction

We are trying to eliminate the whole doTransaction traversal. Following
queued-transaction changes we can update various values on flinger
directly rather than in-directing through the main-thread.

Test: Existing tests pass. simpleperf
Bug: 186200583
Change-Id: I0536f889602ce0801e9f79881bbe1adb7b163d46

services/surfaceflinger/Layer.cpp

diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index b819dbe..6c9905e 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -679,11 +679,6 @@
 uint32_t Layer::doTransaction(uint32_t flags) {
     ATRACE_CALL();
 
-    if (mChildrenChanged) {
-        flags |= eVisibleRegion;
-        mChildrenChanged = false;
-    }
-
     // TODO: This is unfortunate.
     mDrawingStateModified = mDrawingState.modified;
     mDrawingState.modified = false;
@@ -1562,7 +1557,7 @@
 }
 
 void Layer::addChild(const sp<Layer>& layer) {
-    mChildrenChanged = true;
+    mFlinger->mSomeChildrenChanged = true;
     setTransactionFlags(eTransactionNeeded);
 
     mCurrentChildren.add(layer);
@@ -1572,7 +1567,7 @@
 }
 
 ssize_t Layer::removeChild(const sp<Layer>& layer) {
-    mChildrenChanged = true;
+    mFlinger->mSomeChildrenChanged = true;
     setTransactionFlags(eTransactionNeeded);
 
     layer->setParent(nullptr);

services/surfaceflinger/Layer.h

diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 9b30fcb..84d6d3f 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -1003,9 +1003,6 @@
     wp<Layer> mCurrentParent;
     wp<Layer> mDrawingParent;
 
-    // Can only be accessed with the SF state lock held.
-    bool mChildrenChanged{false};
-
     // Window types from WindowManager.LayoutParams
     const InputWindowInfo::Type mWindowType;
 

services/surfaceflinger/SurfaceFlinger.cpp

diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index c6841ed..26581a0 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -2942,6 +2942,11 @@
         });
     }
 
+    if (mSomeChildrenChanged) {
+        mVisibleRegionsDirty = true;
+        mSomeChildrenChanged = false;
+    }
+
     // Update transform hint
     if (transactionFlags & (eTransformHintUpdateNeeded | eDisplayTransactionNeeded)) {
         // The transform hint might have changed for some layers

services/surfaceflinger/SurfaceFlinger.h

diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 22d17eb..81f569a 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -1228,8 +1228,13 @@
     // don't need synchronization
     State mDrawingState{LayerVector::StateSet::Drawing};
     bool mVisibleRegionsDirty = false;
-    // Set during transaction commit stage to track if the input info for a layer has changed.
+
+    // Set during transaction application stage to track if the input info or children
+    // for a layer has changed.
+    // TODO: Also move visibleRegions over to a boolean system.
     bool mInputInfoChanged = false;
+    bool mSomeChildrenChanged;
+
     bool mGeometryInvalid = false;
     bool mAnimCompositionPending = false;