framework: defer creation of participant to solve random crash problem in ut case

framework/cybertron/transport/transport.cpp

@@ -15,12 +15,19 @@
  *****************************************************************************/
 
 #include "cybertron/transport/transport.h"
+
+#include <mutex>
+
 #include "cybertron/common/global_data.h"
 
 namespace apollo {
 namespace cybertron {
 namespace transport {
 
+static std::mutex participant_mutex_;
+
+ParticipantPtr Transport::participant_ = nullptr;
+
 Transport::Transport() {}
 
 Transport::~Transport() {}
@@ -32,7 +39,16 @@ ParticipantPtr Transport::CreateParticipant() {
   return std::make_shared<Participant>(participant_name, 11512);
 }
 
-ParticipantPtr Transport::participant_ = CreateParticipant();
+ParticipantPtr Transport::participant() {
+  if (participant_ != nullptr) {
+    return participant_;
+  }
+  std::lock_guard<std::mutex> lck(participant_mutex_);
+  if (participant_ == nullptr) {
+    participant_ = CreateParticipant();
+  }
+  return participant_;
+}
 
 }  // namespace transport
 }  // namespace cybertron

framework/cybertron/transport/transport.h

@@ -57,7 +57,7 @@ class Transport {
       const OptionalMode& mode = OptionalMode::HYBRID) ->
       typename std::shared_ptr<LowerReach<MessageT>>;
 
-  static ParticipantPtr participant() { return participant_; }
+  static ParticipantPtr participant();
 
  private:
   static ParticipantPtr CreateParticipant();
@@ -86,12 +86,12 @@ auto Transport::CreateUpperReach(const RoleAttributes& attr,
 
     case OptionalMode::RTPS:
       upper_reach = std::make_shared<RtpsUpperReach<MessageT>>(modified_attr,
-                                                               participant_);
+                                                               participant());
       break;
 
     default:
       upper_reach = std::make_shared<HybridUpperReach<MessageT>>(modified_attr,
-                                                                 participant_);
+                                                                 participant());
       break;
   }
 
@@ -132,7 +132,7 @@ auto Transport::CreateLowerReach(
 
     default:
       lower_reach = std::make_shared<HybridLowerReach<MessageT>>(
-          modified_attr, msg_listener, participant_);
+          modified_attr, msg_listener, participant());
       break;
   }