Fix spinning TaskPersister

Wait on the lock if the queue is paused instead of
just spin-looping.

Test: Close app, make sure screenshot gets persisted.
Bug: 36631902
Change-Id: Id7940468391d6cdfc74bb9341c1639f72d469387

1 files changed, 3 insertions, 2 deletions

diff --git a/services/core/java/com/android/server/wm/TaskSnapshotPersister.java b/services/core/java/com/android/server/wm/TaskSnapshotPersister.java
index 028707004773..866bfc015a5f 100644
--- a/services/core/java/com/android/server/wm/TaskSnapshotPersister.java
+++ b/services/core/java/com/android/server/wm/TaskSnapshotPersister.java
@@ -209,11 +209,12 @@ class TaskSnapshotPersister {
                     SystemClock.sleep(DELAY_MS);
                 }
                 synchronized (mLock) {
-                    if (!mWriteQueue.isEmpty()) {
+                    final boolean writeQueueEmpty = mWriteQueue.isEmpty();
+                    if (!writeQueueEmpty && !mPaused) {
                         continue;
                     }
                     try {
-                        mQueueIdling = true;
+                        mQueueIdling = writeQueueEmpty;
                         mLock.wait();
                         mQueueIdling = false;
                     } catch (InterruptedException e) {