teraterm/teraterm/WSAAsyncGetAddrInfo.c

/*
 * WSAAsyncGetAddrInfo.c -- asynchronous version of getaddrinfo
 * Copyright(C) 2000-2003 Jun-ya Kato <kato@win6.jp>
 */
#include <winsock2.h>
#include <ws2tcpip.h>
#include <windows.h>
#include <process.h>
#include "WSAASyncGetAddrInfo.h"

static unsigned __stdcall getaddrinfo_thread(void FAR * p);

HANDLE WSAAsyncGetAddrInfo(HWND hWnd, unsigned int wMsg,
                           const char FAR * hostname,
                           const char FAR * portname,
                           struct addrinfo FAR * hints,
                           struct addrinfo FAR * FAR * res)
{
        HANDLE thread;
        unsigned tid;
        struct getaddrinfo_args FAR * ga;

        /*
        * allocate structure to pass args to sub-thread dynamically
        * WSAAsyncGetAddrInfo() is reentrant
        */
        if ((ga = (struct getaddrinfo_args FAR *)malloc(sizeof(struct getaddrinfo_args))) == NULL)
                return NULL;

        /* packing arguments struct addrinfo_args */
        ga->hWnd = hWnd;
        ga->wMsg = wMsg;
        ga->hostname = hostname;
        ga->portname = portname;
        ga->hints = hints;
        ga->res = res;

        ga->lpHandle = (HANDLE FAR *)malloc(sizeof(HANDLE));
        if (ga->lpHandle == NULL)
                return NULL;

        /* create sub-thread running getaddrinfo() */
        thread = (HANDLE)_beginthreadex(NULL, 0, getaddrinfo_thread, ga, CREATE_SUSPENDED, &tid);
        *ga->lpHandle = (HANDLE)thread;
        ResumeThread(thread);

        /* return thread handle */
        if (thread == 0) {
                free(ga->lpHandle);
                free(ga);
                return NULL;
        } else
                return (HANDLE)thread;
}

static unsigned __stdcall getaddrinfo_thread(void FAR * p)
{
        int gai;
        HWND hWnd;
        unsigned int wMsg;
        const char FAR * hostname;
        const char FAR * portname;
        struct addrinfo FAR * hints;
        struct addrinfo FAR * FAR * res;
        struct getaddrinfo_args FAR * ga;

        /* unpacking arguments */
        ga = (struct getaddrinfo_args FAR *)p;
        hWnd = ga->hWnd;
        wMsg = ga->wMsg;
        hostname = ga->hostname;
        portname = ga->portname;
        hints = ga->hints;
        res = ga->res;

        /* call getaddrinfo */
        gai = getaddrinfo(hostname, portname, hints, res);

        /* send value of gai as message to window hWnd */
        PostMessage(hWnd, wMsg, (WPARAM)*ga->lpHandle, MAKELPARAM(0, gai));

        free(ga->lpHandle);
        free(p);

        return 0;
}