ran client sessions in separated thread pool

mcc/mcc_netserver.h

@@ -23,6 +23,7 @@
 #include <asio/signal_set.hpp>
 #include <asio/steady_timer.hpp>
 #include <asio/streambuf.hpp>
+#include <asio/thread_pool.hpp>
 #include <asio/write.hpp>
 
 #include <spdlog/sinks/null_sink.h>
@@ -181,7 +182,8 @@ public:
           _asioContext(ctx),
           _handleMessageFunc(func),
           _stopSignal(ctx),
-          _restartSignal(ctx)
+          _restartSignal(ctx),
+          _sessionThreadPool(7)
     {
         std::stringstream st;
         st << std::this_thread::get_id();
@@ -359,10 +361,21 @@ public:
 
                 // start accepting connections
                 for (;;) {
+                    st.str("");
+                    st << std::this_thread::get_id();
+                    logDebug(std::format("Start accepting new connections (thread ID = {}) ...", st.str()));
+
                     auto sock = co_await acc.async_accept(asio::use_awaitable);
+
                     // start new client session
-                    asio::co_spawn(_asioContext, startSession(std::move(sock)), asio::detached);
-                    logDebug(std::format("session was spawned, start accepting new connections ..."));
+                    logDebug("Spawn new user session ...");
+
+                    // asio::co_spawn(_asioContext, startSession(std::move(sock)), asio::detached);
+
+                    // use of sessions own thread pool
+                    asio::co_spawn(_sessionThreadPool, startSession(std::move(sock)), asio::detached);
+
+                    logDebug("The session was spawned");
                 }
 
 
@@ -621,6 +634,8 @@ protected:
 
     std::mutex _serialPortsMutex, _tcpSocketsMutex, _localStreamSocketsMutex, _localSeqpackSocketsMutex;
 
+    asio::thread_pool _sessionThreadPool;
+
     // helpers
     template <typename OptT, typename... OptTs>
     void setSerialOpts(asio::serial_port& s_port, OptT&& opt, OptTs&&... opts)