CameraService: Treat TOP_SLEEPING same as TOP for priority.

When arbitrating between camera clients, treat processes in the
TOP_SLEEPING state with the same high priority as processes in the
TOP state.

This resolves race conditions during lock screen handoffs between
clients such as face unlock (a bound foreground process) and a
secure camera app (the topmost activity, but transitioning from
TOP_SLEEPING to TOP asynchronously from the activity lifecycle
callbacks).

Bug: 23731720
Change-Id: I92c3f8f561c7725627826c0ba3dc926e99af746c

2 files changed, 7 insertions, 0 deletions

diff --git a/services/camera/libcameraservice/CameraService.cpp b/services/camera/libcameraservice/CameraService.cpp
index d289704..f5a0887 100644
--- a/services/camera/libcameraservice/CameraService.cpp
+++ b/services/camera/libcameraservice/CameraService.cpp
@@ -602,6 +602,11 @@ int CameraService::getCameraPriorityFromProcState(int procState) {
                 procState);
         return -1;
     }
+    // Treat sleeping TOP processes the same as regular TOP processes, for
+    // access priority.  This is important for lock-screen camera launch scenarios
+    if (procState == PROCESS_STATE_TOP_SLEEPING) {
+        procState = PROCESS_STATE_TOP;
+    }
     return INT_MAX - procState;
 }
 
diff --git a/services/camera/libcameraservice/CameraService.h b/services/camera/libcameraservice/CameraService.h
index a8c6b6c..330a19d 100644
--- a/services/camera/libcameraservice/CameraService.h
+++ b/services/camera/libcameraservice/CameraService.h
@@ -75,6 +75,8 @@ public:
 
     // Process state (mirrors frameworks/base/core/java/android/app/ActivityManager.java)
     static const int PROCESS_STATE_NONEXISTENT = -1;
+    static const int PROCESS_STATE_TOP = 2;
+    static const int PROCESS_STATE_TOP_SLEEPING = 5;
 
     // 3 second busy timeout when other clients are connecting
     static const nsecs_t DEFAULT_CONNECT_TIMEOUT_NS = 3000000000;