windows网络模型之重叠IO(完成例程)的使用

#include <WINSOCK2.H>
#include <stdio.h>

#define PORT    5150
#define MSGSIZE 1024

#pragma comment(lib, "ws2_32.lib")

typedef struct
{
WSAOVERLAPPED overlap;
WSABUF        Buffer;
  char          szMessage[MSGSIZE];
DWORD         NumberOfBytesRecvd;
DWORD         Flags;
SOCKET        sClient;
}PER_IO_OPERATION_DATA, *LPPER_IO_OPERATION_DATA;

DWORD WINAPI WorkerThread(LPVOID);
void CALLBACK CompletionROUTINE(DWORD, DWORD, LPWSAOVERLAPPED, DWORD);

SOCKET g_sNewClientConnection;
BOOL   g_bNewConnectionArrived = FALSE;

int main()
{
  WSADATA     wsaData;
  SOCKET      sListen;
  SOCKADDR_IN local, client;
  DWORD       dwThreadId;
  int         iaddrSize = sizeof(SOCKADDR_IN);

  // Initialize Windows Socket library
  WSAStartup(0x0202, &wsaData);

  // Create listening socket
  sListen = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

  // Bind
  local.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
local.sin_family = AF_INET;
local.sin_port = htons(PORT);
  bind(sListen, (struct sockaddr *)&local, sizeof(SOCKADDR_IN));

  // Listen
  listen(sListen, 3);

  // Create worker thread
  CreateThread(NULL, 0, WorkerThread, NULL, 0, &dwThreadId);

  while (TRUE)
  {
    // Accept a connection
    g_sNewClientConnection = accept(sListen, (struct sockaddr *)&client, &iaddrSize);
    g_bNewConnectionArrived = TRUE;
    printf("Accepted client:%s:%d
", inet_ntoa(client.sin_addr), ntohs(client.sin_port));
  }
}

DWORD WINAPI WorkerThread(LPVOID lpParam)
{
LPPER_IO_OPERATION_DATA lpPerIOData = NULL;

  while (TRUE)
  {
    if (g_bNewConnectionArrived)
    {
      // Launch an asynchronous operation for new arrived connection
      lpPerIOData = (LPPER_IO_OPERATION_DATA)HeapAlloc(
        GetProcessHeap(),
        HEAP_ZERO_MEMORY,
        sizeof(PER_IO_OPERATION_DATA));
      lpPerIOData->Buffer.len = MSGSIZE;
      lpPerIOData->Buffer.buf = lpPerIOData->szMessage;
      lpPerIOData->sClient = g_sNewClientConnection;
     
      WSARecv(lpPerIOData->sClient,
        &lpPerIOData->Buffer,
        1,
        &lpPerIOData->NumberOfBytesRecvd,
        &lpPerIOData->Flags,
        &lpPerIOData->overlap,
        CompletionROUTINE);     
     
      g_bNewConnectionArrived = FALSE;
    }

    SleepEx(1000, TRUE);　　　　　　　　　　　　　　　　　　//这里如果不sleep,根本不会进入完成例程的回调,第一个参数时间可以适当缩小
  }
  return 0;
}

void CALLBACK CompletionROUTINE(DWORD dwError,
                                DWORD cbTransferred,
                                LPWSAOVERLAPPED lpOverlapped,
                                DWORD dwFlags)
{
  LPPER_IO_OPERATION_DATA lpPerIOData = (LPPER_IO_OPERATION_DATA)lpOverlapped;
 
  　　if (dwError != 0 || cbTransferred == 0)
　　{
    　　// Connection was closed by client
  　　closesocket(lpPerIOData->sClient);
  　　HeapFree(GetProcessHeap(), 0, lpPerIOData);
　　}
  　　else
  {
    lpPerIOData->szMessage[cbTransferred] = '