simplify storage SIGINT signal handler

src/daemons/StorageDaemon.cpp

@@ -180,7 +180,7 @@ void signalHandler(int sig) {
     case SIGTERM:
       FLOG_INFO("Signal %d(%s) received, stopping this server", sig, ::strsignal(sig));
       if (gStorageServer) {
-        gStorageServer->stop();
+        gStorageServer->notifyStop();
       }
       break;
     default:

src/storage/StorageServer.cpp

@@ -305,15 +305,40 @@ bool StorageServer::start() {
       internalStorageSvcStatus_.load() != STATUS_RUNNING) {
     return false;
   }
+  {
+    std::lock_guard<std::mutex> lkStop(muStop_);
+    if (serverStatus_ != STATUS_UNINITIALIZED) {
+      // stop() called during start()
+      return false;
+    }
+    serverStatus_ = STATUS_RUNNING;
+  }
   return true;
 }
 
 void StorageServer::waitUntilStop() {
+  {
+    std::unique_lock<std::mutex> lkStop(muStop_);
+    while (serverStatus_ == STATUS_RUNNING) {
+      cvStop_.wait(lkStop);
+    }
+  }
+
+  this->stop();
+
   adminThread_->join();
   storageThread_->join();
   internalStorageThread_->join();
 }
 
+void StorageServer::notifyStop() {
+  std::unique_lock<std::mutex> lkStop(muStop_);
+  if (serverStatus_ == STATUS_RUNNING) {
+    serverStatus_ = STATUS_STOPPED;
+    cvStop_.notify_one();
+  }
+}
+
 void StorageServer::stop() {
   if (adminSvcStatus_.load() == ServiceStatus::STATUS_STOPPED &&
       storageSvcStatus_.load() == ServiceStatus::STATUS_STOPPED &&

src/storage/StorageServer.h

@@ -39,6 +39,9 @@ class StorageServer final {
 
   void stop();
 
+  // used for signal handler to set an internal stop flag
+  void notifyStop();
+
   void waitUntilStop();
 
  private:
@@ -88,6 +91,10 @@ class StorageServer final {
   std::unique_ptr<TransactionManager> txnMan_{nullptr};
   // used for communicate between one storaged to another
   std::unique_ptr<InternalStorageClient> interClient_;
+
+  ServiceStatus serverStatus_{STATUS_UNINITIALIZED};
+  std::mutex muStop_;
+  std::condition_variable cvStop_;
 };
 
 }  // namespace storage

src/storage/transaction/TransactionManager.cpp

@@ -98,6 +98,7 @@ bool TransactionManager::start() {
 }
 
 void TransactionManager::stop() {
+  exec_->stop();
   resumeThread_->stop();
   resumeThread_->wait();
 }