Oat++ server provider not listening on port

Question

I am trying to write a wrapper around the Oat++ system to simplify usage across multiple microservices, but, I have run into an issue.

Aim

I want to be able to specify the service provider points (address, port and address type of IPV4/IPV6) via a class function.

Issue

If I run the minimum viable code below and try to connect to HTTP:://localhost:8888/test I can't connect to the port (I get a timeout). If I change the dynamic for loop for the hard-coded provider and try to connect I get the expected 404.

So change:

        for (auto entry = m_serviceProviderEntry.begin ();
             entry != m_serviceProviderEntry.end (); entry++)
        {
            auto addrType = (*entry).networkType == SERVICENETWORKTYPE_IPV4 ?
                oatpp::network::Address::IP_4 : oatpp::network::Address::IP_6;
            auto provider = oatpp::network::tcp::server::ConnectionProvider::createShared (
                { (*entry).address, v_uint16 ((*entry).networkPort), addrType });
            m_connectionProviders.push_back (provider);

            oatpp::network::Server server (provider, m_connectionHandler);
            server.run (true);
        }

for:

auto provider = oatpp::network::tcp::server::ConnectionProvider::createShared (
                { "localhost", 8888, oatpp::network::Address::IP_4 });
oatpp::network::Server server (provider, m_connectionHandler);
server.run (true);
        }

Any suggestions or help would be gratefully appreciated as I don't understand why this is failing as it is, maybe use of std::shared_ptr in a std::list?

Minimal viable and repeatable code

#include <winsock2.h>
#include "oatpp/web/server/HttpConnectionHandler.hpp"
#include "oatpp/network/tcp/server/ConnectionProvider.hpp"
#include "oatpp/network/Server.hpp"

enum ServiceNetworkType
{
    SERVICENETWORKTYPE_IPV4,
    SERVICENETWORKTYPE_IPV6
};

struct ServiceProviderEntry
{
    std::string address;
    v_uint16 networkPort;
    ServiceNetworkType networkType;
};

class Example
{
public:
    Example () : m_shutdownRequested (false) { }

    bool Initialise ()
    {
        int iResult;
        WSADATA wsaData;
        iResult = WSAStartup (MAKEWORD (2, 2), &wsaData);
        if (iResult != 0) return false;

        return true;
    }

    void Execute ()
    {
        m_router = oatpp::web::server::HttpRouter::createShared ();
        m_connectionHandler = oatpp::web::server::HttpConnectionHandler::createShared (m_router);

        for (auto entry = m_serviceProviderEntry.begin ();
             entry != m_serviceProviderEntry.end (); entry++)
        {
            auto addrType = (*entry).networkType == SERVICENETWORKTYPE_IPV4 ?
                oatpp::network::Address::IP_4 : oatpp::network::Address::IP_6;
            auto provider = oatpp::network::tcp::server::ConnectionProvider::createShared (
                { (*entry).address, v_uint16 ((*entry).networkPort), addrType });
            m_connectionProviders.push_back (provider);

            oatpp::network::Server server (provider, m_connectionHandler);
            server.run (true);
        }

        while (!m_shutdownRequested) { }
    }

    void AddServiceProvider (std::string address,
        int networkPort,
        ServiceNetworkType networkType)
    {
        ServiceProviderEntry entry = { address,
                                       v_uint16 (networkPort),
                                       networkType };
        m_serviceProviderEntry.push_back (entry);
    }

private:
    bool m_shutdownRequested;

    std::shared_ptr<oatpp::web::server::HttpRouter> m_router;
    std::shared_ptr<oatpp::web::server::HttpConnectionHandler> m_connectionHandler;
    std::list <std::shared_ptr<oatpp::network::tcp::server::ConnectionProvider>> m_connectionProviders;
    std::list<ServiceProviderEntry> m_serviceProviderEntry;
};

int main ()
{
    auto app = new Example ();
    app->Initialise ();
    app->AddServiceProvider ("localhost", 8888, SERVICENETWORKTYPE_IPV4);
    app->Execute ();
    return EXIT_SUCCESS;
}

Answer 1

Here is the issue:

for(...) {
   oatpp::network::Server server (provider, m_connectionHandler); // Server object created
   server.run (true); // Run server accept loop in a separate thread
} // Server object deleted, server accept loop is terminated

At the end of each iteration your server object is deleted.
ConnectionProvider object is deleted too.

Possible solution would look something like the following:

std::list<std::shared_ptr<oatpp::network::Server>> servers;
for(...) {
  ...
  auto server = std::make_shared<oatpp::network::Server>(provider, m_connectionHandler);
  server->run(true);
  servers.push_back(server);
}