ch07l03.txt

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Listing 7.3 A simple thread-pool-based server program.

#define WIN32_EXTRA_LEAN
#include <windows.h>
#include <winsock.h>
#include <wsipx.h>
#include <conio.h>
#include "aes.h"

#define SERVER_SOCKET   0x3200

SOCKET g_skt;
BOOL g_serverUp;
AES *g_aesp;
AES::AESHandle g_hEvent;

void ServerThread(void *)
{
    if (!g_serverUp)
       return;
    fd_set rdSkts;
    FD_ZERO(&rdSkts);
    FD_SET(g_skt, &rdSkts);
    struct timeval tv = {5,0};
    int rval = select(0, &rdSkts, 0, 0, &tv);

// schedule another pool thread to listen
    g_hEvent = g_aesp->ScheduleEvent(0, ServerThread, 0);

    // use this thread to process client request to completion
    if (rval < 0)
        printf("Winsock: select returned %d.\n", WSAGetLastError());
    else if (rval > 0)
    {
        SOCKADDR_IPX addr;
        int recvLen, addrLen = sizeof addr;
        char recvBuf[5];
        if ((recvLen = recvfrom(g_skt, recvBuf, sizeof recvBuf, 0,
            (struct sockaddr *)&addr, &addrLen)) == SOCKET_ERROR) 
        {
          printf("Winsock: recvfrom returned %d.\n",WSAGetLastError());
          return;
        }
        char *resp = strncmp(recvBuf,"Ping",5)?"101 Invalid Request.":
                     "Pong";
        int respLen = strlen(resp) + 1;
        if (sendto(g_skt, resp, respLen, 0, (struct sockaddr *)&addr, 
                                             sizeof addr) == SOCKET_ERROR)
            printf("Winsock: sendto returned %d.\n", WSAGetLastError());
    }
    return;
}

BOOL StartServer(WORD wSocket) 
{
    int err;
    SOCKADDR_IPX addr;
    WSADATA wsaData;

    if (!(g_aesp = new AES))
    {
        printf("Unable to create AES object.\n");
        return FALSE;
    }

if (err = WSAStartup(MAKEWORD(1,1), &wsaData))
    {
        printf("WSAStartup returned %d.\n", err);
        goto errout1;
    }

    if (LOBYTE(wsaData.wVersion) < 1 || HIBYTE(wsaData.wVersion) < 1)
    {
        printf("Winsock version too low.\n");
        goto errout2;
    }

    if ((g_skt = socket(AF_IPX, SOCK_DGRAM, NSPROTO_IPX)) == INVALID_SOCKET)
   {
        printf("Windsock: socket returned %d.\n", WSAGetLastError());
        goto errout2;
    }

    memset(&addr, 0, sizeof(SOCKADDR_IPX));
    addr.sa_family = AF_IPX;
    addr.sa_socket = htons(wSocket);

    if (bind(g_skt, (struct sockaddr *) &addr, sizeof(SOCKADDR_IPX)) != 0)
    {
        printf("Winsock: bind returned %d.\n", WSAGetLastError());
        goto errout3;
    }
    g_serverUp = TRUE;

    if (!(g_hEvent = g_aesp->ScheduleEvent(0, ServerThread, 0)))
    {
        printf("AES: Unable to schedule event.\n");
        g_serverUp = FALSE;
        goto errout3;
    }
    return TRUE;

errout3:
    closesocket(g_skt);

errout2:
    WSACleanup();

errout1:
    delete g_aesp;
    return FALSE;
}

void StopServer(void) 
{
    g_serverUp = FALSE;
    g_aesp->CancelEvent(g_hEvent);
    delete g_aesp;
    closesocket(g_skt);
    WSACleanup();
    return;
}

void main(void)
{
    if (StartServer(SERVER_SOCKET))
    {
        printf("Server running, press any key to terminate...\n");
        getch();
        StopServer();
    }
    printf("Server terminated, press any key to exit...\n");
    getch();
    return;
}