Fixed undefined behavior of detached thread (#663)

Author: JohanMabille

include/xeus-python/xdebugger.hpp

@@ -17,12 +17,14 @@
 #endif
 
 #include <map>
+#include <memory>
 #include <mutex>
 #include <set>
 
 #include "nlohmann/json.hpp"
 #include "pybind11/pybind11.h"
 #include "xeus-zmq/xdebugger_base.hpp"
+#include "xeus-zmq/xthread.hpp"
 #include "xeus_python_config.hpp"
 
 namespace py = pybind11;
@@ -62,11 +64,12 @@ namespace xpyt
         xeus::xdebugger_info get_debugger_info() const override;
         std::string get_cell_temporary_file(const std::string& code) const override;
 
-        xdebugpy_client* p_debugpy_client;
+        std::unique_ptr<xdebugpy_client> p_debugpy_client;
         std::string m_debugpy_host;
         std::string m_debugpy_port;
         nl::json m_debugger_config;
         py::object m_pydebugger;
+        xeus::xthread m_client_runner;
         bool m_copy_to_globals_available;
     };
 

src/xdebugger.cpp

@@ -70,8 +70,6 @@ namespace xpyt
 
     debugger::~debugger()
     {
-        delete p_debugpy_client;
-        p_debugpy_client = nullptr;
     }
 
     nl::json debugger::inspect_variables_request(const nl::json& message)
@@ -325,13 +323,12 @@ namespace xpyt
         bind_sockets(controller_header_end_point, controller_end_point);
 
         std::string debugpy_end_point = "tcp://" + m_debugpy_host + ':' + m_debugpy_port;
-        std::thread client(&xdap_tcp_client::start_debugger,
-                           p_debugpy_client,
+        m_client_runner = xeus::xthread(&xdap_tcp_client::start_debugger,
+                           p_debugpy_client.get(),
                            debugpy_end_point,
                            publisher_end_point,
                            controller_end_point,
                            controller_header_end_point);
-        client.detach();
 
         send_recv_request("REQ");