DO NOT MERGE: ViewRootImpl: Add P2P sync primitive am: e5d1324755 (b65a2595) · Commits · e / os / android_frameworks_base

core/java/android/view/ViewRootImpl.java

+42 −0

Original line number	Original line	Diff line number	Diff line
	@@ -208,6 +208,7 @@ import java.io.PrintWriter;
	import java.io.StringWriter;		import java.io.StringWriter;
	import java.lang.ref.WeakReference;		import java.lang.ref.WeakReference;
	import java.util.ArrayList;		import java.util.ArrayList;
			import java.util.function.Consumer;
	import java.util.HashSet;		import java.util.HashSet;
	import java.util.LinkedList;		import java.util.LinkedList;
	import java.util.List;		import java.util.List;
	@@ -757,6 +758,8 @@ public final class ViewRootImpl implements ViewParent,
	*/		*/
	private boolean mNextDrawUseBlastSync = false;		private boolean mNextDrawUseBlastSync = false;

			private Consumer<SurfaceControl.Transaction> mBLASTDrawConsumer;

	/**		/**
	* Wait for the blast sync transaction complete callback before drawing and queuing up more		* Wait for the blast sync transaction complete callback before drawing and queuing up more
	* frames. This will prevent out of order buffers submissions when WM has requested to		* frames. This will prevent out of order buffers submissions when WM has requested to
	@@ -3351,6 +3354,9 @@ public final class ViewRootImpl implements ViewParent,
	}		}

	boolean cancelDraw = mAttachInfo.mTreeObserver.dispatchOnPreDraw() \|\| !isViewVisible;		boolean cancelDraw = mAttachInfo.mTreeObserver.dispatchOnPreDraw() \|\| !isViewVisible;
			if (mBLASTDrawConsumer != null) {
			mNextDrawUseBlastSync = true;
			}

	if (!cancelDraw) {		if (!cancelDraw) {
	if (mPendingTransitions != null && mPendingTransitions.size() > 0) {		if (mPendingTransitions != null && mPendingTransitions.size() > 0) {
	@@ -4049,6 +4055,8 @@ public final class ViewRootImpl implements ViewParent,
	*/		*/
	private HardwareRenderer.FrameCompleteCallback createFrameCompleteCallback(Handler handler,		private HardwareRenderer.FrameCompleteCallback createFrameCompleteCallback(Handler handler,
	boolean reportNextDraw, ArrayList<Runnable> commitCallbacks) {		boolean reportNextDraw, ArrayList<Runnable> commitCallbacks) {
			final Consumer<SurfaceControl.Transaction> blastSyncConsumer = mBLASTDrawConsumer;
			mBLASTDrawConsumer = null;
	return frameNr -> {		return frameNr -> {
	if (DEBUG_BLAST) {		if (DEBUG_BLAST) {
	Log.d(mTag, "Received frameCompleteCallback frameNum=" + frameNr);		Log.d(mTag, "Received frameCompleteCallback frameNum=" + frameNr);
	@@ -4061,6 +4069,9 @@ public final class ViewRootImpl implements ViewParent,
	// is only true when the UI thread is paused. Therefore, no one should be		// is only true when the UI thread is paused. Therefore, no one should be
	// modifying this object until the next vsync.		// modifying this object until the next vsync.
	mSurfaceChangedTransaction.merge(mRtBLASTSyncTransaction);		mSurfaceChangedTransaction.merge(mRtBLASTSyncTransaction);
			if (blastSyncConsumer != null) {
			blastSyncConsumer.accept(mSurfaceChangedTransaction);
			}
	}		}

	if (reportNextDraw) {		if (reportNextDraw) {
	@@ -10550,4 +10561,35 @@ public final class ViewRootImpl implements ViewParent,
	listener.onBufferTransformHintChanged(hint);		listener.onBufferTransformHintChanged(hint);
	}		}
	}		}

			/**
			* Redirect the next draw of this ViewRoot (from the UI thread perspective)
			* to the passed in consumer. This can be used to create P2P synchronization
			* between ViewRoot's however it comes with many caveats.
			*
			* 1. You MUST consume the transaction, by either applying it immediately or
			* merging it in to another transaction. The threading model doesn't
			* allow you to hold in the passed transaction.
			* 2. If you merge it in to another transaction, this ViewRootImpl will be
			* paused until you finally apply that transaction and it receives
			* the callback from SF. If you lose track of the transaction you will
			* ANR the app.
			* 3. Only one person can consume the transaction at a time, if you already
			* have a pending consumer for this frame, the function will return false
			* 4. Someone else may have requested to consume the next frame, in which case
			* this function will return false and you will not receive a callback.
			* 5. This function does not trigger drawing so even if it returns true you
			* may not receive a callback unless there is some other UI thread work
			* to trigger drawing. If it returns true, and a draw occurs, the callback
			* will be called (Though again watch out for the null transaction case!)
			* 6. This function must be called on the UI thread. The consumer will likewise
			* be called on the UI thread.
			*/
			public boolean consumeNextDraw(Consumer<SurfaceControl.Transaction> consume) {
			if (mBLASTDrawConsumer != null) {
			return false;
			}
			mBLASTDrawConsumer = consume;
			return true;
			}
	}		}