Use BBQ syncing instead of blocking in VRI (76fca86c) · Commits · e / os / android_frameworks_base

core/java/android/view/ViewRootImpl.java

+25 −101

Original line number	Diff line number	Diff line
		@@ -735,47 +735,20 @@ public final class ViewRootImpl implements ViewParent,
		}

		/**
		* This is only used when the UI thread is paused due to {@link #mNextDrawUseBlastSync} being
		* set. Specifically, it's only used when calling
		* {@link BLASTBufferQueue#setNextTransaction(Transaction)} and then merged with
		* {@link #mSurfaceChangedTransaction}. It doesn't need to be thread safe since it's only
		* accessed when the UI thread is paused.
		* This is only used on the RenderThread when handling a blast sync. Specifically, it's only
		* used when calling {@link BLASTBufferQueue#setNextTransaction(Transaction)} and then merged
		* with a tmp transaction on the Render Thread. The tmp transaction is then merged into
		* {@link #mSurfaceChangedTransaction} on the UI Thread, avoiding any threading issues.
		*/
		private final SurfaceControl.Transaction mRtBLASTSyncTransaction =
		new SurfaceControl.Transaction();

		/**
		* Keeps track of whether the WM requested to use BLAST Sync when calling relayout. When set,
		* we pause the UI thread to ensure we don't get overlapping requests. We then send a
		* transaction to {@link BLASTBufferQueue#setNextTransaction(Transaction)}, which is then sent
		* back to WM to synchronize.
		*
		* This flag is set to false only after the synchronized transaction that contains the buffer
		* has been sent to SurfaceFlinger.
		*/
		private boolean mNextDrawUseBlastSync = false;

		/**
		* 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
		* synchronize with the client.
		*/
		private boolean mWaitForBlastSyncComplete = false;

		/**
		* Keeps track of the last frame number that was attempted to draw. Should only be accessed on
		* the RenderThread.
		*/
		private long mRtLastAttemptedDrawFrameNum = 0;

		/**
		* Keeps track of whether a traverse was triggered while the UI thread was paused. This can
		* occur when the client is waiting on another process to submit the transaction that
		* contains the buffer. The UI thread needs to wait on the callback before it can submit
		* another buffer.
		*/
		private boolean mRequestedTraverseWhilePaused = false;

		private HashSet<ScrollCaptureCallback> mRootScrollCaptureCallbacks;

		private long mScrollCaptureRequestTimeout = SCROLL_CAPTURE_REQUEST_TIMEOUT_MILLIS;
		@@ -1620,7 +1593,7 @@ public final class ViewRootImpl implements ViewParent,
		mForceNextWindowRelayout = forceNextWindowRelayout;
		mPendingAlwaysConsumeSystemBars = args.argi2 != 0;

		if (msg == MSG_RESIZED_REPORT && !mNextDrawUseBlastSync) {
		if (msg == MSG_RESIZED_REPORT) {
		reportNextDraw();
		}

		@@ -2515,23 +2488,6 @@ public final class ViewRootImpl implements ViewParent,
		return;
		}

		// This is to ensure we don't end up queueing new frames while waiting on a previous frame
		// to get latched. This can happen when there's been a sync request for this window. The
		// frame could be in a transaction that's passed to different processes to ensure
		// synchronization. It continues to block until ViewRootImpl receives a callback that the
		// transaction containing the buffer has been sent to SurfaceFlinger. Once we receive, that
		// signal, we know it's safe to start queuing new buffers.
		//
		// When the callback is invoked, it will trigger a traversal request if
		// mRequestedTraverseWhilePaused is set so there's no need to attempt a retry here.
		if (mWaitForBlastSyncComplete) {
		if (DEBUG_BLAST) {
		Log.w(mTag, "Can't perform draw while waiting for a transaction complete");
		}
		mRequestedTraverseWhilePaused = true;
		return;
		}

		mIsInTraversal = true;
		mWillDrawSoon = true;
		boolean windowSizeMayChange = false;
		@@ -2775,6 +2731,7 @@ public final class ViewRootImpl implements ViewParent,
		}
		}
		final boolean wasReportNextDraw = mReportNextDraw;
		boolean useBlastSync = false;

		if (mFirst \|\| windowShouldResize \|\| viewVisibilityChanged \|\| params != null
		\|\| mForceNextWindowRelayout) {
		@@ -2827,7 +2784,7 @@ public final class ViewRootImpl implements ViewParent,
		}
		reportNextDraw();
		if (isHardwareEnabled()) {
		mNextDrawUseBlastSync = true;
		useBlastSync = true;
		}
		}

		@@ -3301,7 +3258,7 @@ public final class ViewRootImpl implements ViewParent,
		}
		mPendingTransitions.clear();
		}
		performDraw();
		performDraw(useBlastSync);
		} else {
		if (isViewVisible) {
		// Try again
		@@ -3986,22 +3943,6 @@ public final class ViewRootImpl implements ViewParent,
		}
		}

		/**
		* Only call this on the UI Thread.
		*/
		void clearBlastSync() {
		mNextDrawUseBlastSync = false;
		mWaitForBlastSyncComplete = false;
		if (DEBUG_BLAST) {
		Log.d(mTag, "Scheduling a traversal=" + mRequestedTraverseWhilePaused
		+ " due to a previous skipped traversal.");
		}
		if (mRequestedTraverseWhilePaused) {
		mRequestedTraverseWhilePaused = false;
		scheduleTraversals();
		}
		}

		/**
		* @hide
		*/
		@@ -4009,12 +3950,13 @@ public final class ViewRootImpl implements ViewParent,
		return mAttachInfo.mThreadedRenderer != null && mAttachInfo.mThreadedRenderer.isEnabled();
		}

		private boolean addFrameCompleteCallbackIfNeeded(boolean reportNextDraw) {
		private boolean addFrameCompleteCallbackIfNeeded(boolean useBlastSync,
		boolean reportNextDraw) {
		if (!isHardwareEnabled()) {
		return false;
		}

		if (!mNextDrawUseBlastSync && !reportNextDraw) {
		if (!useBlastSync && !reportNextDraw) {
		return false;
		}

		@@ -4036,30 +3978,22 @@ public final class ViewRootImpl implements ViewParent,
		// for the current draw attempt.
		if (frameWasNotDrawn) {
		mBlastBufferQueue.setNextTransaction(null);
		mBlastBufferQueue.setTransactionCompleteCallback(mRtLastAttemptedDrawFrameNum,
		null);
		// Apply the transactions that were sent to mergeWithNextTransaction since the
		// frame didn't draw on this vsync. It's possible the frame will draw later, but
		// it's better to not be sync than to block on a frame that may never come.
		mBlastBufferQueue.applyPendingTransactions(mRtLastAttemptedDrawFrameNum);
		}

		Transaction tmpTransaction = new Transaction();
		tmpTransaction.merge(mRtBLASTSyncTransaction);
		mHandler.postAtFrontOfQueue(() -> {
		if (mNextDrawUseBlastSync) {
		// We don't need to synchronize mRtBLASTSyncTransaction here since we're
		// guaranteed that this is called after onFrameDraw and mNextDrawUseBlastSync
		// is only true when the UI thread is paused. Therefore, no one should be
		// modifying this object until the next vsync.
		mSurfaceChangedTransaction.merge(mRtBLASTSyncTransaction);
		if (useBlastSync) {
		mSurfaceChangedTransaction.merge(tmpTransaction);
		}

		if (reportNextDraw) {
		pendingDrawFinished();
		}

		if (frameWasNotDrawn) {
		clearBlastSync();
		}
		});
		});
		return true;
		@@ -4095,21 +4029,19 @@ public final class ViewRootImpl implements ViewParent,
		});
		}

		private void addFrameCallbackIfNeeded() {
		final boolean nextDrawUseBlastSync = mNextDrawUseBlastSync;
		private void addFrameCallbackIfNeeded(boolean useBlastSync) {
		final boolean hasBlurUpdates = mBlurRegionAggregator.hasUpdates();
		final boolean needsCallbackForBlur = hasBlurUpdates \|\| mBlurRegionAggregator.hasRegions();

		if (!nextDrawUseBlastSync && !needsCallbackForBlur) {
		if (!useBlastSync && !needsCallbackForBlur) {
		return;
		}

		if (DEBUG_BLAST) {
		Log.d(mTag, "Creating frameDrawingCallback"
		+ " nextDrawUseBlastSync=" + nextDrawUseBlastSync
		+ " nextDrawUseBlastSync=" + useBlastSync
		+ " hasBlurUpdates=" + hasBlurUpdates);
		}
		mWaitForBlastSyncComplete = nextDrawUseBlastSync;
		final BackgroundBlurDrawable.BlurRegion[] blurRegionsForFrame =
		needsCallbackForBlur ? mBlurRegionAggregator.getBlurRegionsCopyForRT() : null;

		@@ -4117,7 +4049,7 @@ public final class ViewRootImpl implements ViewParent,
		HardwareRenderer.FrameDrawingCallback frameDrawingCallback = frame -> {
		if (DEBUG_BLAST) {
		Log.d(mTag, "Received frameDrawingCallback frameNum=" + frame + "."
		+ " Creating transactionCompleteCallback=" + nextDrawUseBlastSync);
		+ " Creating transactionCompleteCallback=" + useBlastSync);
		}

		mRtLastAttemptedDrawFrameNum = frame;
		@@ -4131,7 +4063,7 @@ public final class ViewRootImpl implements ViewParent,
		return;
		}

		if (nextDrawUseBlastSync) {
		if (useBlastSync) {
		// Frame callbacks will always occur after submitting draw requests and before
		// the draw actually occurs. This will ensure that we set the next transaction
		// for the frame that's about to get drawn and not on a previous frame that.
		@@ -4139,35 +4071,27 @@ public final class ViewRootImpl implements ViewParent,
		// We don't need to synchronize mRtBLASTSyncTransaction here since it's not
		// being modified and only sent to BlastBufferQueue.
		mBlastBufferQueue.setNextTransaction(mRtBLASTSyncTransaction);

		mBlastBufferQueue.setTransactionCompleteCallback(frame, frameNumber -> {
		if (DEBUG_BLAST) {
		Log.d(mTag, "Received transactionCompleteCallback frameNum=" + frame);
		}
		mHandler.postAtFrontOfQueue(this::clearBlastSync);
		});
		}
		};
		registerRtFrameCallback(frameDrawingCallback);
		}

		private void performDraw() {
		private void performDraw(boolean useBlastSync) {
		if (mAttachInfo.mDisplayState == Display.STATE_OFF && !mReportNextDraw) {
		return;
		} else if (mView == null) {
		return;
		}

		final boolean fullRedrawNeeded =
		mFullRedrawNeeded \|\| mReportNextDraw \|\| mNextDrawUseBlastSync;
		final boolean fullRedrawNeeded = mFullRedrawNeeded \|\| mReportNextDraw \|\| useBlastSync;
		mFullRedrawNeeded = false;

		mIsDrawing = true;
		Trace.traceBegin(Trace.TRACE_TAG_VIEW, "draw");

		addFrameCallbackIfNeeded();
		addFrameCallbackIfNeeded(useBlastSync);
		addFrameCommitCallbackIfNeeded();
		boolean usingAsyncReport = addFrameCompleteCallbackIfNeeded(mReportNextDraw);
		boolean usingAsyncReport = addFrameCompleteCallbackIfNeeded(useBlastSync, mReportNextDraw);

		try {
		boolean canUseAsync = draw(fullRedrawNeeded);
		@@ -4412,7 +4336,7 @@ public final class ViewRootImpl implements ViewParent,
		mChoreographer.getFrameTimeNanos() / TimeUtils.NANOS_PER_MS;

		boolean useAsyncReport = false;
		if (!dirty.isEmpty() \|\| mIsAnimating \|\| accessibilityFocusDirty \|\| mNextDrawUseBlastSync) {
		if (!dirty.isEmpty() \|\| mIsAnimating \|\| accessibilityFocusDirty) {
		if (isHardwareEnabled()) {
		// If accessibility focus moved, always invalidate the root.
		boolean invalidateRoot = accessibilityFocusDirty \|\| mInvalidateRootRequested;