Merge "SurfaceView: positionLost locking fix" into rvc-dev am: bff3812e82 am: f19bd92daf (32cdfa75) · Commits · e / os / android_frameworks_base

core/java/android/view/SurfaceView.java

+28 −7

Original line number	Original line	Diff line number	Diff line
	@@ -134,6 +134,23 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
	// we need to preserve the old one until the new one has drawn.		// we need to preserve the old one until the new one has drawn.
	SurfaceControl mDeferredDestroySurfaceControl;		SurfaceControl mDeferredDestroySurfaceControl;
	SurfaceControl mBackgroundControl;		SurfaceControl mBackgroundControl;

			/**
			* We use this lock in SOME cases when reading or writing SurfaceControl,
			* but use the following model so that the RenderThread can run locklessly
			* in the position up-date case.
			*
			* 1. UI Thread can read from mSurfaceControl (use in Transactions) without
			* holding the lock.
			* 2. UI Thread will hold the lock when writing to mSurfaceControl (calling release
			* or remove).
			* 3. Render thread will also hold the lock when writing to mSurfaceControl (e.g.
			* calling release from positionLost).
			* 3. RenderNode.PositionUpdateListener::positionChanged will only be called
			* when the UI thread is paused (blocked on the Render thread).
			* 4. positionChanged thus will not be required to hold the lock as the
			* UI thread is blocked, and the other writer is the RT itself.
			*/
	final Object mSurfaceControlLock = new Object();		final Object mSurfaceControlLock = new Object();
	final Rect mTmpRect = new Rect();		final Rect mTmpRect = new Rect();

	@@ -1297,6 +1314,11 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
	(viewRoot != null ? viewRoot.getBLASTSyncTransaction() : mRtTransaction) :		(viewRoot != null ? viewRoot.getBLASTSyncTransaction() : mRtTransaction) :
	mRtTransaction;		mRtTransaction;

			/**
			* positionLost can be called while UI thread is un-paused so we
			* need to hold the lock here.
			*/
			synchronized (mSurfaceControlLock) {
	if (frameNumber > 0 && viewRoot != null && !useBLAST) {		if (frameNumber > 0 && viewRoot != null && !useBLAST) {
	if (viewRoot.mSurface.isValid()) {		if (viewRoot.mSurface.isValid()) {
	mRtTransaction.deferTransactionUntil(mSurfaceControl,		mRtTransaction.deferTransactionUntil(mSurfaceControl,
	@@ -1305,7 +1327,6 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
	}		}
	t.hide(mSurfaceControl);		t.hide(mSurfaceControl);

	synchronized (mSurfaceControlLock) {
	if (mRtReleaseSurfaces) {		if (mRtReleaseSurfaces) {
	mRtReleaseSurfaces = false;		mRtReleaseSurfaces = false;
	mRtTransaction.remove(mSurfaceControl);		mRtTransaction.remove(mSurfaceControl);