commit eae73eb726c141056caf5a7ff95d45c3bcdd999f
author Mikhail Naganov <mnaganov@google.com> Tue Apr 03 16:57:36 2018 -0700
committer Mikhail Naganov <mnaganov@google.com> Wed Apr 04 15:55:12 2018 -0700
tree f0e034a867acf3af218b60a9bdc947ddc31e47cc
parent 728f909a1fecb99e565a0239580c5e9fff264209

AudioPolicyService: Properly handle service restarts in UidPolicy

Add logic in UidPolicy for handling audioserver restarts as well
as ActivityManager (system server) restarts.

Also, refactor the UidPolicy logic to simplify reasoning about
active state lookup. As a result, 4 layers are considered:

1. Service UIDs--always active.
2. Overrides--controlled via 'adb shell cmd'.
3. Cached UIDs from ActivityManager--also updated via IUidObserver.
4. ActivityManager ground truth.

Bug: 73405145
Bug: 77300296
Test: android.media.cts.AudioRecordTest#testRecordNoDataForIdleUids
      manual tests with SoloTester
Change-Id: I426dd5d4d9c9c2570c0e03dde390e18f672c1b1d

services/audiopolicy/service/AudioPolicyService.h

diff --git a/services/audiopolicy/service/AudioPolicyService.h b/services/audiopolicy/service/AudioPolicyService.h
index bfa3ef4..b3bc12b 100644
--- a/services/audiopolicy/service/AudioPolicyService.h
+++ b/services/audiopolicy/service/AudioPolicyService.h
@@ -35,7 +35,6 @@
 #include "managerdefault/AudioPolicyManager.h"
 
 #include <unordered_map>
-#include <unordered_set>
 
 namespace android {
 
@@ -264,31 +263,40 @@
     // transparently handles recording while the UID transitions between idle/active state
     // avoiding to get stuck in a state receiving non-empty buffers while idle or in a state
     // receiving empty buffers while active.
-    class UidPolicy : public BnUidObserver {
+    class UidPolicy : public BnUidObserver, public virtual IBinder::DeathRecipient {
     public:
         explicit UidPolicy(wp<AudioPolicyService> service)
-                : mService(service) {}
+                : mService(service), mObserverRegistered(false) {}
 
         void registerSelf();
         void unregisterSelf();
 
+        // IBinder::DeathRecipient implementation
+        void binderDied(const wp<IBinder> &who) override;
+
         bool isUidActive(uid_t uid);
 
-        void onUidGone(uid_t uid, bool disabled);
-        void onUidActive(uid_t uid);
-        void onUidIdle(uid_t uid, bool disabled);
+        // BnUidObserver implementation
+        void onUidActive(uid_t uid) override;
+        void onUidGone(uid_t uid, bool disabled) override;
+        void onUidIdle(uid_t uid, bool disabled) override;
 
-        void addOverrideUid(uid_t uid, bool active);
-        void removeOverrideUid(uid_t uid);
+        void addOverrideUid(uid_t uid, bool active) { updateOverrideUid(uid, active, true); }
+        void removeOverrideUid(uid_t uid) { updateOverrideUid(uid, false, false); }
 
     private:
-        bool isUidActiveLocked(uid_t uid);
+        bool isServiceUid(uid_t uid) const;
+        void notifyService(uid_t uid, bool active);
         void updateOverrideUid(uid_t uid, bool active, bool insert);
+        void updateUidCache(uid_t uid, bool active, bool insert);
+        void updateUidLocked(std::unordered_map<uid_t, bool> *uids,
+                uid_t uid, bool active, bool insert, bool *wasThere, bool *wasActive);
 
-        Mutex mUidLock;
         wp<AudioPolicyService> mService;
-        std::unordered_set<uid_t> mActiveUids;
+        Mutex mLock;
+        bool mObserverRegistered;
         std::unordered_map<uid_t, bool> mOverrideUids;
+        std::unordered_map<uid_t, bool> mCachedUids;
     };
 
     // Thread used for tone playback and to send audio config commands to audio flinger