Modelica socket communication (Part 1: socket library, code listing)

This page lists the code referred to in my blog post here.

Socket.c contains the following (note that this hasn’t been tested under Windows).

#ifdef _WIN32
  #include "winsock2.h"
#else
  #include <sys/socket.h>
  #include <sys/types.h>
  #include <netinet/in.h>
  #include <string.h>
#endif

#include <stdio.h>

 
static int s = 0;
static char receive_buffer[255];


int startup()
{
    #ifdef _WIN32
      WSADATA wsa;
      return WSAStartup(MAKEWORD(2,0), &wsa);
    #else
      return 0;
    #endif
}


int create_socket(const char* ip_address, int port)
{
    #ifdef _WIN32
      struct SOCKADDR_IN addr;
    #else
      struct sockaddr_in addr;
    #endif

    s = socket(AF_INET, SOCK_STREAM, 0);

    memset(&addr, 0, sizeof(addr));

    addr.sin_family = AF_INET;
    addr.sin_port = htons(port); 
    addr.sin_addr.s_addr = inet_addr(ip_address); 
    
    #ifdef _WIN32
      if (connect(s, (struct SOCKADDR*)&addr, sizeof(addr)) == INVALID_SOCKET)
          return 1;
      else
          return 0;
    #else
      if (connect(s, (struct sockaddr*)&addr, sizeof(addr)) < 0)
          return 1;
      else
          return 0;
    #endif
}


void send_message(char* buf)
{
    
    send(s, buf, strlen(buf), 0);
}


char* receive_message()
{
    recv(s, receive_buffer, 255, 0);
    return receive_buffer;
}


int cleanup()
{
    #ifdef _WIN32
      WSACleanup();
    #endif
    return 0;
}
Loading Facebook Comments ...
  1. […] Modelica socket communication (Part 1: socket library) […]

  2. […] The first step in setting up socket communication within a Modelica simulation is to create a socket library that can be called from the simulation code. Fortunately, this is very simple C code. You can find the relevant code here. […]