rework client using async api

webcc/connection_pool.cc

@@ -5,11 +5,11 @@
 namespace webcc {
 
 void ConnectionPool::Start(ConnectionPtr c) {
-  LOG_VERB("Starting connection...");
+  LOG_VERB("Start connection");
 
   {
     // Lock the container only.
-    std::lock_guard<std::mutex> lock(mutex_);
+    std::lock_guard<std::mutex> lock{ mutex_ };
     connections_.insert(c);
   }
 
@@ -17,11 +17,11 @@ void ConnectionPool::Start(ConnectionPtr c) {
 }
 
 void ConnectionPool::Close(ConnectionPtr c) {
-  LOG_VERB("Closing connection...");
+  LOG_VERB("Close connection");
 
   {
     // Lock the container only.
-    std::lock_guard<std::mutex> lock(mutex_);
+    std::lock_guard<std::mutex> lock{ mutex_ };
     connections_.erase(c);
   }
 
@@ -30,10 +30,10 @@ void ConnectionPool::Close(ConnectionPtr c) {
 
 void ConnectionPool::Clear() {
   // Lock all since we are going to stop anyway.
-  std::lock_guard<std::mutex> lock(mutex_);
+  std::lock_guard<std::mutex> lock{ mutex_ };
 
   if (!connections_.empty()) {
-    LOG_VERB("Closing all (%u) connections...", connections_.size());
+    LOG_VERB("Close all (%u) connections", connections_.size());
     for (auto& c : connections_) {
       c->Close();
     }