Camera: synchronize access to mHidlMemPoolMap

Test: stress test by HAL1 partner
Bug: 65431027
Change-Id: Ia13f0f65b72ff459f59bb4a566b571de37ee4716
Merged-In: Ia13f0f65b72ff459f59bb4a566b571de37ee4716
diff --git a/services/camera/libcameraservice/device1/CameraHardwareInterface.h b/services/camera/libcameraservice/device1/CameraHardwareInterface.h
index 1c38d00..2f1e2e9 100644
--- a/services/camera/libcameraservice/device1/CameraHardwareInterface.h
+++ b/services/camera/libcameraservice/device1/CameraHardwareInterface.h
@@ -523,6 +523,7 @@
     uint64_t mNextBufferId = 1;
     static const uint64_t BUFFER_ID_NO_BUFFER = 0;
 
+    std::mutex mHidlMemPoolMapLock; // protecting mHidlMemPoolMap
     std::unordered_map<int, camera_memory_t*> mHidlMemPoolMap;
 };