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Commit 89f28270 authored by Vishnu Nair's avatar Vishnu Nair
Browse files

Fix ViewRootImpl traversal issue after SurfaceSyncGroup timeout 

ViewRootImpl traversal is blocked from the time a sync is requested
to when the sync is successfully added to a SurfaceSyncGroup.
If the ViewRootImpl draw timeouts, the ViewRootImpl's
SurfaceSyncGroup is marked as ready. If there is another
sync request on the ViewRootImpl before the traversal path,
we can get in a state where we will never draw again.

Fix this by updating cleaning up the ViewRootImpl state
when the SurfaceSyncGroup is marked as ready.

Flag: EXEMPT bug fix
Bug: 362513091
Test: presubmit (coming in future cl)
Change-Id: I6c0ac8f96914d231cc9dc695f6fc8975ba2c5864
parent 0c06c085

core/java/android/view/ViewRootImpl.java

+33 −8
Original line number Diff line number Diff line
@@ -6971,9 +6971,7 @@ public final class ViewRootImpl implements ViewParent, 
                    handleScrollCaptureRequest((IScrollCaptureResponseListener) msg.obj);

                    break;

                case MSG_PAUSED_FOR_SYNC_TIMEOUT:

                    Log.e(mTag, "Timedout waiting to unpause for sync");

                    mNumPausedForSync = 0;

                    scheduleTraversals();

                    resumeAfterSyncTimeout();

                    break;

                case MSG_CHECK_INVALIDATION_IDLE: {

                    long delta;
@@ -12766,6 +12764,15 @@ public final class ViewRootImpl implements ViewParent, 
        activeSurfaceSyncGroup.addTransaction(t);

    }













    /**













     * Resume rendering after being paused for sync due to a timeout.













     */













    private void resumeAfterSyncTimeout() {













        Log.e(mTag, "Timedout waiting to unpause for sync mNumPausedForSync=" + mNumPausedForSync);













        mNumPausedForSync = 0;













        scheduleTraversals();













    }



























    @Override















    public SurfaceSyncGroup getOrCreateSurfaceSyncGroup() {















        boolean newSyncGroup = false;










@@ -12793,6 +12800,16 @@ public final class ViewRootImpl implements ViewParent,













                }















            });















            newSyncGroup = true;

























            // If the sync group is marked ready by a timeout, check if rendering is paused and













            // if it is, resume rendering and trigger a traversal.













            mActiveSurfaceSyncGroup.addSyncCompleteCallback(mExecutor, () -> {













                if (mActiveSurfaceSyncGroup != null













                        && mActiveSurfaceSyncGroup.isComplete() && mNumPausedForSync > 0) {













                    mHandler.removeMessages(MSG_PAUSED_FOR_SYNC_TIMEOUT);













                    resumeAfterSyncTimeout();













                }













            });















        }





























        Trace.instant(Trace.TRACE_TAG_VIEW,









@@ -12807,12 +12824,20 @@ public final class ViewRootImpl implements ViewParent,













            }















        }



























        // The sync group can be marked ready by a timeout. This makes incrementing













        // mNumPausedForSync racy. Here we check if the sync group is complete and













        // if it is then we don't pause for syncing.













        if (!mActiveSurfaceSyncGroup.isComplete()) {















            mNumPausedForSync++;















            mHandler.removeMessages(MSG_PAUSED_FOR_SYNC_TIMEOUT);















            mHandler.sendEmptyMessageDelayed(MSG_PAUSED_FOR_SYNC_TIMEOUT,















                    1000 * Build.HW_TIMEOUT_MULTIPLIER);













        } else {













            Log.d(mTag, "Active sync group is already completed "













                    + mActiveSurfaceSyncGroup.getName());













        }















        return mActiveSurfaceSyncGroup;













    };













    }





























    private final Executor mSimpleExecutor = Runnable::run;







































core/java/android/window/SurfaceSyncGroup.java



+10
−0




























Original line number
Diff line number
Diff line








@@ -838,6 +838,16 @@ public final class SurfaceSyncGroup {













        mHandler.postDelayed(runnable, this, TRANSACTION_READY_TIMEOUT);















    }





























    /**













     * Returns true if the SurfaceSyncGroup has completed its sync.













     * @hide













     */













    public boolean isComplete() {













        synchronized (mLock) {













            return mFinished;













        }













    }





























    /**















     * A frame callback that is used to synchronize SurfaceViews. The owner of the SurfaceView must















     * implement onFrameStarted when trying to sync the SurfaceView. This is to ensure the sync