#18 add lock to pub data

Author: KingRichord

example/NetCam/mv_cam.cpp

@@ -264,7 +264,7 @@ void MvCam::Start() {
       LOG(INFO) << "Camera name is " << name;
     }
     cam_threads.emplace_back(&MvCam::Receive, this, handle, name);
-    LOG(INFO) << "Camera name is " << name << " start.";
+    LOG(INFO) << "Camera " << name << " start.";
   }
 }
 }  // namespace infinite_sense

infinite_sense_core/include/messenger.h

@@ -3,6 +3,7 @@
 #include <thread>
 #include <zmq.hpp>
 #include <functional>
+#include <mutex>
 
 namespace infinite_sense {
 class Messenger {
@@ -23,6 +24,7 @@ class Messenger {
   Messenger();
   ~Messenger();
   void CleanUp();
+  std::mutex mutex_;
   zmq::context_t context_{};
   zmq::socket_t publisher_{}, subscriber_{};
   std::string endpoint_{};

infinite_sense_core/src/messenger.cpp

@@ -39,6 +39,7 @@ void Messenger::CleanUp() {
 
 void Messenger::Pub(const std::string& topic, const std::string& metadata) {
   try {
+    std::lock_guard lock(mutex_);
     publisher_.send(zmq::buffer(topic), zmq::send_flags::sndmore);
     publisher_.send(zmq::buffer(metadata), zmq::send_flags::dontwait);
   } catch (const zmq::error_t& e) {
@@ -48,6 +49,7 @@ void Messenger::Pub(const std::string& topic, const std::string& metadata) {
 
 void Messenger::PubStruct(const std::string& topic, const void* data, const size_t size) {
   try {
+    std::lock_guard lock(mutex_);
     publisher_.send(zmq::buffer(topic), zmq::send_flags::sndmore);
     publisher_.send(zmq::buffer(data, size), zmq::send_flags::dontwait);
   } catch (const zmq::error_t& e) {