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

Fix deadlock by not acquiring lock when reporting proximity

Browse Source 
There is a deadlock situation from AttentionManagerService acquiring
lock before callings back to its clients with the proximity update. This
can cause a deadlock because the clients, while holding their own locks,
can call AttentionManagerService again.

Thread 1:
  Acquires attention lock -> AttentionManager Service reports proximityUpdate to VoiceInteraction -> tries to acquire voice lock

Thread 2:
  Acquires voice lock -> VoiceService tries to cancel proximity updates
  -> tries to acquire attention lock

The deadlock can be fixed by removing the acquiring attention lock step
before reporting proximityUpdates to the clients.

Bug: 261143716
Test: atest CtsAttentionServiceDeviceTestCases
Change-Id: I9f7d520cbcfd57032a9476853acad025fd7a6b95
This commit is contained in:
Daniel
2022-12-23 02:14:45 +00:00
parent 81b2644ede
commit a28af297d3
1 changed files with 1 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
services/core/java/com/android/server/attention/AttentionManagerService.java
View File

@@ -668,8 +668,8 @@ public class AttentionManagerService extends SystemService {
mIProximityUpdateCallback = new IProximityUpdateCallback.Stub() { mIProximityUpdateCallback = new IProximityUpdateCallback.Stub() {
@Override @Override
public void onProximityUpdate(double distance) { public void onProximityUpdate(double distance) {
mCallbackInternal.onProximityUpdate(distance);
synchronized (mLock) { synchronized (mLock) {
mCallbackInternal.onProximityUpdate(distance);
freeIfInactiveLocked(); freeIfInactiveLocked();
} }
} }