cameraserver: Avoiding deadlocks while calling isPublicallyHiddenSecureCamera().
The following scenario can occur:
T1 serving Client A's disconnect() call:
T2 : serving Client B's connect() call
T2 : CameraProviderManager::openSession() locks mInterfaceMutex and waits on open() HAL
interface call
T1: updateStatus() locks mStatusListenerMutex
T1: CameraProviderManager::isPublicallyHiddenSecureCamera() waits
on mInterfaceMutex
T2: while waiting on open(), gets a torchModeStatus() callback from the camera HAL
T2: onStatusChanged()
T2: broadcastTorchModeStatus() which waits on mStatusListenerMutex
As a result there's a possible circular hold and wait between T1 and T2.
We cache isPublicallyHiddenSecureCamera in CameraState. That doesn't completely
avoid having to hold mInterfaceLock while calling isPublicallyHiddenSecureCamera() in CameraService
(cache updates), instead it reduces it. We instead need to hold mCameraStates lock which has a
smaller scope.
Bug: 141756275
Test: CTS
Test: GCA (sanity)
Merged-In: I4a697c1eaccc3603007be4a595febea981fbeb64
Change-Id: Ie5508afb126a874f76fbbfc2dd19ef79ae6255e0
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>
diff --git a/services/camera/libcameraservice/CameraService.h b/services/camera/libcameraservice/CameraService.h
index cf93a41..8bb78cd 100644
--- a/services/camera/libcameraservice/CameraService.h
+++ b/services/camera/libcameraservice/CameraService.h
@@ -471,7 +471,8 @@
* Make a new CameraState and set the ID, cost, and conflicting devices using the values
* returned in the HAL's camera_info struct for each device.
*/
- CameraState(const String8& id, int cost, const std::set<String8>& conflicting);
+ CameraState(const String8& id, int cost, const std::set<String8>& conflicting,
+ bool isHidden);
virtual ~CameraState();
/**
@@ -523,6 +524,11 @@
*/
String8 getId() const;
+ /**
+ * Return if the camera device is a publically hidden secure camera
+ */
+ bool isPublicallyHiddenSecureCamera() const;
+
private:
const String8 mId;
StatusInternal mStatus; // protected by mStatusLock
@@ -530,6 +536,7 @@
std::set<String8> mConflicting;
mutable Mutex mStatusLock;
CameraParameters mShimParams;
+ const bool mIsPublicallyHiddenSecureCamera;
}; // class CameraState
// Observer for UID lifecycle enforcing that UIDs in idle
@@ -635,7 +642,9 @@
// Should an operation attempt on a cameraId be rejected, if the camera id is
// advertised as a publically hidden secure camera, by the camera HAL ?
- bool shouldRejectHiddenCameraConnection(const String8 & cameraId);
+ bool shouldRejectHiddenCameraConnection(const String8& cameraId);
+
+ bool isPublicallyHiddenSecureCamera(const String8& cameraId);
// Single implementation shared between the various connect calls
template<class CALLBACK, class CLIENT>