Android/frameworks_base
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge "SurfaceView: positionLost locking fix" into rvc-dev

Browse Source
This commit is contained in:
TreeHugger Robot
2020-05-13 22:04:58 +00:00
committed by Android (Google) Code Review
parent 730fb0d97d ebaaca1a46
commit bff3812e82
1 changed files with 29 additions and 8 deletions
Download Patch File Download Diff File Expand all files Collapse all files

37
core/java/android/view/SurfaceView.java
View File

@@ -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.
SurfaceControl mDeferredDestroySurfaceControl;
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 Rect mTmpRect = new Rect();
@@ -1297,15 +1314,19 @@ public class SurfaceView extends View implements ViewRootImpl.SurfaceChangedCall
(viewRoot != null ? viewRoot.getBLASTSyncTransaction() : mRtTransaction) :
mRtTransaction;
if (frameNumber > 0 && viewRoot != null && !useBLAST) {
if (viewRoot.mSurface.isValid()) {
mRtTransaction.deferTransactionUntil(mSurfaceControl,
viewRoot.getRenderSurfaceControl(), frameNumber);
}
}
t.hide(mSurfaceControl);
/**
* 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 (viewRoot.mSurface.isValid()) {
mRtTransaction.deferTransactionUntil(mSurfaceControl,
viewRoot.getRenderSurfaceControl(), frameNumber);
}
}
t.hide(mSurfaceControl);
if (mRtReleaseSurfaces) {
mRtReleaseSurfaces = false;
mRtTransaction.remove(mSurfaceControl);