Merge "SurfaceView: Fix unsafe transaction accesses" (05f920bb) · Commits · e / os / android_frameworks_base

core/java/android/view/SurfaceView.java

+49 −56

Original line number	Diff line number	Diff line
		@@ -138,20 +138,9 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
		private boolean mDisableBackgroundLayer = false;

		/**
		* 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.
		* We use this lock to protect access to mSurfaceControl and
		* SurfaceViewPositionUpdateListener#mPositionChangedTransaction. Both are accessed on the UI
		* thread and the render thread.
		*/
		final Object mSurfaceControlLock = new Object();
		final Rect mTmpRect = new Rect();
		@@ -951,8 +940,10 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
		Transaction geometryTransaction) {
		if (mPositionListener != null) {
		mRenderNode.removePositionUpdateListener(mPositionListener);
		synchronized (mSurfaceControlLock) {
		geometryTransaction = mPositionListener.getTransaction().merge(geometryTransaction);
		}
		}
		mPositionListener = new SurfaceViewPositionUpdateListener(surfaceWidth, surfaceHeight,
		geometryTransaction);
		mRenderNode.addPositionUpdateListener(mPositionListener);
		@@ -1480,7 +1471,6 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
		if (mSurfaceControl == null) {
		return;
		}
		}
		if (mRTLastReportedPosition.left == left
		&& mRTLastReportedPosition.top == top
		&& mRTLastReportedPosition.right == right
		@@ -1503,8 +1493,10 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
		onSetSurfacePositionAndScaleRT(mPositionChangedTransaction, mSurfaceControl,
		mRTLastReportedPosition.left /positionLeft/,
		mRTLastReportedPosition.top /positionTop/,
		mRTLastReportedPosition.width() / (float) mRtSurfaceWidth /postScaleX/,
		mRTLastReportedPosition.height() / (float) mRtSurfaceHeight /postScaleY/);
		mRTLastReportedPosition.width()
		/ (float) mRtSurfaceWidth /postScaleX/,
		mRTLastReportedPosition.height()
		/ (float) mRtSurfaceHeight /postScaleY/);
		if (mViewVisibility) {
		mPositionChangedTransaction.show(mSurfaceControl);
		}
		@@ -1519,6 +1511,7 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
		Log.e(TAG, "Exception from repositionChild", ex);
		}
		}
		}

		@Override
		public void applyStretch(long frameNumber, float width, float height,
		@@ -1539,18 +1532,18 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
		}
		mRTLastReportedPosition.setEmpty();
		mRTLastReportedSurfaceSize.set(-1, -1);
		if (mPendingTransaction) {
		Log.w(TAG, System.identityHashCode(SurfaceView.this)
		+ "Pending transaction cleared.");
		mPositionChangedTransaction.clear();
		mPendingTransaction = false;
		}

		/**
		* positionLost can be called while UI thread is un-paused so we
		* need to hold the lock here.
		*/
		synchronized (mSurfaceControlLock) {
		if (mPendingTransaction) {
		Log.w(TAG, System.identityHashCode(SurfaceView.this)
		+ "Pending transaction cleared.");
		mPositionChangedTransaction.clear();
		mPendingTransaction = false;
		}
		if (mSurfaceControl == null) {
		return;
		}