SurfaceFlinger: Share ownership of layers between State and Handle.
Currently the only strong reference to a Layer is held by their parent
or the containing layer stack. Firstly, it means that we can not
create a SurfaceControl with a null parent. For example, a
media decoding library may wish to offer an unparented SurfaceControl
representing the decoding Surface, and allow the consumer to parent
it between various SurfaceControls as they wish. Secondly it requires
lifetime coordination between various levels of the hierarchy, when adding
a child you have to be careful to observe the lifetime of the parent because
your BufferQueue may become suddenly abandoned at any point. In this change
we switch to a reference counted model, such that the Layer remains valid
as long as there is a handle to it. We also end the behavior of passing on
BufferQueue abandon to children. Layers are only abandoned/disposed when
an explicit call to remove is made, or the last reference is dropped.
In this CL we switch the handle to holding a strong pointer.
We have the handle and the current state forward their references
to the main thread to be dropped. We move the contents of onRemoved
to the destructor to ensure they are dropped when the last reference
is dropped. A second CL will replace the concept of "onRemovedFromCurrentState"
with the concept of parent=null, and remove the explicit destroy method,
replacing it with an IPC reparent to null.
Bug: 62536731
Bug: 111373437
Bug: 111297488
Test: Transaction_test.cpp
Change-Id: I22a6c1b27bdc5c377369e59613b32078d15ab1c2
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 8afd3b3..9f1c662 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -118,13 +118,20 @@
c->detachLayer(this);
}
- for (auto& point : mRemoteSyncPoints) {
- point->setTransactionApplied();
- }
+ mFrameTracker.logAndResetStats(mName);
+
+ // The remote sync points are cleared out when we are
+ // removed from current state.
+ Mutex::Autolock lock(mLocalSyncPointMutex);
for (auto& point : mLocalSyncPoints) {
point->setFrameAvailable();
}
- mFrameTracker.logAndResetStats(mName);
+
+ abandon();
+
+ destroyAllHwcLayers();
+
+ mFlinger->onLayerDestroyed();
}
// ---------------------------------------------------------------------------
@@ -139,10 +146,9 @@
void Layer::onLayerDisplayed(const sp<Fence>& /*releaseFence*/) {}
void Layer::onRemovedFromCurrentState() {
+ mRemovedFromCurrentState = true;
+
// the layer is removed from SF mCurrentState to mLayersPendingRemoval
-
- mPendingRemoval = true;
-
if (mCurrentState.zOrderRelativeOf != nullptr) {
sp<Layer> strongRelative = mCurrentState.zOrderRelativeOf.promote();
if (strongRelative != nullptr) {
@@ -152,22 +158,21 @@
mCurrentState.zOrderRelativeOf = nullptr;
}
+ // Since we are no longer reachable from CurrentState SurfaceFlinger
+ // will no longer invoke doTransaction for us, and so we will
+ // never finish applying transactions. We signal the sync point
+ // now so that another layer will not become indefinitely
+ // blocked.
+ for (auto& point: mRemoteSyncPoints) {
+ point->setTransactionApplied();
+ }
+ mRemoteSyncPoints.clear();
+
for (const auto& child : mCurrentChildren) {
child->onRemovedFromCurrentState();
}
}
-void Layer::onRemoved() {
- // the layer is removed from SF mLayersPendingRemoval
- abandon();
-
- destroyAllHwcLayers();
-
- for (const auto& child : mCurrentChildren) {
- child->onRemoved();
- }
-}
-
// ---------------------------------------------------------------------------
// set-up
// ---------------------------------------------------------------------------
@@ -227,6 +232,10 @@
}
LOG_ALWAYS_FATAL_IF(!getBE().mHwcLayers.empty(),
"All hardware composer layers should have been destroyed");
+
+ for (const sp<Layer>& child : mDrawingChildren) {
+ child->destroyAllHwcLayers();
+ }
}
Rect Layer::getContentCrop() const {
@@ -783,7 +792,9 @@
// If this transaction is waiting on the receipt of a frame, generate a sync
// point and send it to the remote layer.
- if (mCurrentState.barrierLayer_legacy != nullptr) {
+ // We don't allow installing sync points after we are removed from the current state
+ // as we won't be able to signal our end.
+ if (mCurrentState.barrierLayer_legacy != nullptr && !mRemovedFromCurrentState) {
sp<Layer> barrierLayer = mCurrentState.barrierLayer_legacy.promote();
if (barrierLayer == nullptr) {
ALOGE("[%s] Unable to promote barrier Layer.", mName.string());