sdbusplus：多线程共享同一个bus，做同步调用，行为未定义

//add_service1.cpp
#include <sdbusplus/asio/connection.hpp>
#include <sdbusplus/asio/object_server.hpp>
#include <sdbusplus/bus.hpp>
#include <iostream>
#include <string>
 
using namespace std;
 
int addInt(int d1, int d2)
{
    return d1 + d2;
}
 
string addString(string s1, string s2)
{
    return s1 + s2;
}
 
int main()
{
    boost::asio::io_context io;
    auto conn = std::make_shared<sdbusplus::asio::connection>(io);
    conn->request_name("calculate1.service");
    auto server = sdbusplus::asio::object_server(conn);
    shared_ptr<sdbusplus::asio::dbus_interface> iface = server.add_interface("/calculate_obj","calculate_infterface.data");
    iface->register_method("AddInt", addInt);
    iface->register_method("AddString", addString);
    iface->register_property("data", 18, sdbusplus::asio::PropertyPermission::readWrite);
    if