Merge "Add mInterfaceLock back to Camera3Device methods called by RequestThread."

services/camera/libcameraservice/device3/Camera3Device.cpp

@@ -364,12 +364,12 @@ status_t Camera3Device::disconnect() {
 
 status_t Camera3Device::disconnectImpl() {
     ATRACE_CALL();
-    Mutex::Autolock il(mInterfaceLock);
-
     ALOGI("%s: E", __FUNCTION__);
 
     status_t res = OK;
     std::vector<wp<Camera3StreamInterface>> streams;
+    {
+        Mutex::Autolock il(mInterfaceLock);
         nsecs_t maxExpectedDuration = getExpectedInFlightDuration();
         {
             Mutex::Autolock l(mLock);
@@ -411,16 +411,19 @@ status_t Camera3Device::disconnectImpl() {
                 streams.push_back(mInputStream);
             }
         }
-
-    // Joining done without holding mLock, otherwise deadlocks may ensue
-    // as the threads try to access parent state
+    }
+    // Joining done without holding mLock and mInterfaceLock, otherwise deadlocks may ensue
+    // as the threads try to access parent state (b/143513518)
     if (mRequestThread != NULL && mStatus != STATUS_ERROR) {
         // HAL may be in a bad state, so waiting for request thread
         // (which may be stuck in the HAL processCaptureRequest call)
         // could be dangerous.
+        // give up mInterfaceLock here and then lock it again. Could this lead
+        // to other deadlocks
         mRequestThread->join();
     }
-
+    {
+        Mutex::Autolock il(mInterfaceLock);
         if (mStatusTracker != NULL) {
             mStatusTracker->join();
         }
@@ -457,7 +460,7 @@ status_t Camera3Device::disconnectImpl() {
                         __FUNCTION__, stream->getId(), stream->getStrongCount() - 1);
             }
         }
-
+    }
     ALOGI("%s: X", __FUNCTION__);
     return res;
 }
@@ -1768,9 +1771,7 @@ void Camera3Device::internalUpdateStatusLocked(Status status) {
 }
 
 void Camera3Device::pauseStateNotify(bool enable) {
-    // We must not hold mInterfaceLock here since this function is called from
-    // RequestThread::threadLoop and holding mInterfaceLock could lead to
-    // deadlocks (http://b/143513518)
+    Mutex::Autolock il(mInterfaceLock);
     Mutex::Autolock l(mLock);
 
     mPauseStateNotify = enable;
@@ -2340,9 +2341,7 @@ bool Camera3Device::reconfigureCamera(const CameraMetadata& sessionParams) {
     ATRACE_CALL();
     bool ret = false;
 
-    // We must not hold mInterfaceLock here since this function is called from
-    // RequestThread::threadLoop and holding mInterfaceLock could lead to
-    // deadlocks (http://b/143513518)
+    Mutex::Autolock il(mInterfaceLock);
     nsecs_t maxExpectedDuration = getExpectedInFlightDuration();
 
     Mutex::Autolock l(mLock);

services/camera/libcameraservice/device3/Camera3Device.h

@@ -278,7 +278,6 @@ class Camera3Device :
 
     // A lock to enforce serialization on the input/configure side
     // of the public interface.
-    // Only locked by public methods inherited from CameraDeviceBase.
     // Not locked by methods guarded by mOutputLock, since they may act
     // concurrently to the input/configure side of the interface.
     // Must be locked before mLock if both will be locked by a method