surfaceflinger: distinguish mCurrentParent/mDrawingParent
Updates to wp<> is not atomic. We cannot use/update it at the same
time from the main thread and a binder thread. With this change,
binder threads use mCurrentParent with the external state lock held.
The main thread uses mDrawingParent.
This is also an alternative fix to bug 62099658 and allows us to
revert "SurfaceFlinger: Update parent pointer while performing
transaction."
Bug: 38505866
Bug: 62099658
Test: boots and no repro (but I can never repro)
Change-Id: Id286a437537daaeec5eee5de62b1d9df245ece53
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 5335fff..24fc10d 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -524,7 +524,7 @@
// Returns index if removed, or negative value otherwise
// for symmetry with Vector::remove
ssize_t removeChild(const sp<Layer>& layer);
- sp<Layer> getParent() const { return mParent.promote(); }
+ sp<Layer> getParent() const { return mCurrentParent.promote(); }
bool hasParent() const { return getParent() != nullptr; }
Rect computeScreenBounds(bool reduceTransparentRegion = true) const;
@@ -801,7 +801,8 @@
// Child list used for rendering.
LayerVector mDrawingChildren;
- wp<Layer> mParent;
+ wp<Layer> mCurrentParent;
+ wp<Layer> mDrawingParent;
};
// ---------------------------------------------------------------------------