完成端口例子

// Module Name: iocmplt.cpp
//
// Description:
//
//    This sample illustrates how to develop a simple echo server Winsock
//    application using the completeion port I/O model. This
//    sample is implemented as a console-style application and simply prints
//    messages when connections are established and removed from the server.
//    The application listens for TCP connections on port 5150 and accepts them
//    as they arrive. When this application receives data from a client, it
//    simply echos (this is why we call it an echo server) the data back in
//    it's original form until the client closes the connection.
//
// Compile:
//
//    cl -o iocmplt iocmplt.cpp ws2_32.lib
//
// Command Line Options:
//
//    iocmplt.exe
//
//    Note: There are no command line options for this sample.

#include <winsock2.h>
#include <windows.h>
#include <stdio.h>

#define PORT 5150
#define DATA_BUFSIZE 8192

#pragma comment(lib, "Ws2_32")

typedef struct
{
   OVERLAPPED Overlapped;
   WSABUF DataBuf;
   CHAR Buffer[DATA_BUFSIZE];
   DWORD BytesSEND;
   DWORD BytesRECV;
} PER_IO_OPERATION_DATA, * LPPER_IO_OPERATION_DATA;

typedef struct
{
   SOCKET Socket;
} PER_HANDLE_DATA, * LPPER_HANDLE_DATA;

DWORD WINAPI ServerWorkerThread(LPVOID CompletionPortID);

void main(void)
{
   SOCKADDR_IN InternetAddr;
   SOCKET Listen;
   SOCKET Accept;
   HANDLE CompletionPort;
   SYSTEM_INFO SystemInfo;
   LPPER_HANDLE_DATA PerHandleData;
   LPPER_IO_OPERATION_DATA PerIoData;
   int i;
   DWORD RecvBytes;
   DWORD Flags;
   DWORD ThreadID;
   WSADATA wsaData;
   DWORD Ret;

   if ((Ret = WSAStartup(0x0202, &wsaData)) != 0)
   {
      printf("WSAStartup failed with error %d/n", Ret);
      return;
   }

   // Setup an I/O completion port.

   if ((CompletionPort = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0)) == NULL)
   {
      printf( "CreateIoCompletionPort failed with error: %d/n", GetLastError());
      return;
   }

   // Determine how many processors are on the system.

   GetSystemInfo(&SystemInfo);

   // Create worker threads based on the number of processors available on the
   // system. Create two worker threads for each processor.

   for(i = 0; i < SystemInfo.dwNumberOfProcessors * 2; i++)
   {
      HANDLE ThreadHandle;

      // Create a server worker thread and pass the completion port to the thread.

      if ((ThreadHandle = CreateThread(NULL, 0, ServerWorkerThread, CompletionPort,
         0, &ThreadID)) == NULL)
      {
         printf("CreateThread() failed with error %d/n", GetLastError());
         return;
      }

      // Close the thread handle
      CloseHandle(ThreadHandle);
   }

   // Create a listening socket

   if ((Listen = WSASocket(AF_INET, SOCK_STREAM, 0, NULL, 0,
      WSA_FLAG_OVERLAPPED)) == INVALID_SOCKET)
   {
      printf("WSASocket() failed with error %d/n", WSAGetLastError());
      return;
   }

   InternetAddr.sin_family = AF_INET;
   InternetAddr.sin_addr.s_addr = htonl(INADDR_ANY);
   InternetAddr.sin_port = htons(PORT);

   if (bind(Listen, (PSOCKADDR) &InternetAddr, sizeof(InternetAddr)) == SOCKET_ERROR)
   {
      printf("bind() failed with error %d/n", WSAGetLastError());
      return;
   }

   // Prepare socket for listening

   if (listen(Listen, 5) == SOCKET_ERROR)
   {
      printf("listen() failed with error %d/n", WSAGetLastError());
      return;
   }

   // Accept connections and assign to the completion port.

   while(TRUE)
   {
      if ((Accept = WSAAccept(Listen, NULL, NULL, NULL, 0)) == SOCKET_ERROR)
      {
         printf("WSAAccept() failed with error %d/n", WSAGetLastError());
         return;
      }

      // Create a socket information structure to associate with the socket
      if ((PerHandleData = (LPPER_HANDLE_DATA) GlobalAlloc(GPTR,
         sizeof(PER_HANDLE_DATA))) == NULL)
      {
         printf("GlobalAlloc() failed with error %d/n", GetLastError());
         return;
      }

      // Associate the accepted socket with the original completion port.

      printf("Socket number %d connected/n", Accept);
      PerHandleData->Socket = Accept;

      if (CreateIoCompletionPort((HANDLE) Accept, CompletionPort, (DWORD) PerHandleData,
         0) == NULL)
      {
         printf("CreateIoCompletionPort failed with error %d/n", GetLastError());
         return;
      }

      // Create per I/O socket information structure to associate with the
      // WSARecv call below.

      if ((PerIoData = (LPPER_IO_OPERATION_DATA) GlobalAlloc(GPTR,          sizeof(PER_IO_OPERATION_DATA))) == NULL)
      {
         printf("GlobalAlloc() failed with error %d/n", GetLastError());
         return;
      }

      ZeroMemory(&(PerIoData->Overlapped), sizeof(OVERLAPPED));
      PerIoData->BytesSEND = 0;
      PerIoData->BytesRECV = 0;
      PerIoData->DataBuf.len = DATA_BUFSIZE;
      PerIoData->DataBuf.buf = PerIoData->Buffer;

      Flags = 0;
      if (WSARecv(Accept, &(PerIoData->DataBuf), 1, &RecvBytes, &Flags,
         &(PerIoData->Overlapped), NULL) == SOCKET_ERROR)
      {
         if (WSAGetLastError() != ERROR_IO_PENDING)
         {
            printf("WSARecv() failed with error %d/n", WSAGetLastError());
            return;
         }
      }
   }
}

DWORD WINAPI ServerWorkerThread(LPVOID CompletionPortID)
{
   HANDLE CompletionPort = (HANDLE) CompletionPortID;
   DWORD BytesTransferred;
   LPOVERLAPPED Overlapped;
   LPPER_HANDLE_DATA PerHandleData;
   LPPER_IO_OPERATION_DATA PerIoData;
   DWORD SendBytes, RecvBytes;
   DWORD Flags;
  
   while(TRUE)
   {
  
      if (GetQueuedCompletionStatus(CompletionPort, &BytesTransferred,
         (LPDWORD)&PerHandleData, (LPOVERLAPPED *) &PerIoData, INFINITE) == 0)
      {
         printf("GetQueuedCompletionStatus failed with error %d/n", GetLastError());
         return 0;
      }

      // First check to see if an error has occured on the socket and if so
      // then close the socket and cleanup the SOCKET_INFORMATION structure
      // associated with the socket.

      if (BytesTransferred == 0)
      {
         printf("Closing socket %d/n", PerHandleData->Socket);

         if (closesocket(PerHandleData->Socket) == SOCKET_ERROR)
         {
            printf("closesocket() failed with error %d/n", WSAGetLastError());
            return 0;
         }

         GlobalFree(PerHandleData);
         GlobalFree(PerIoData);
         continue;
      }

      // Check to see if the BytesRECV field equals zero. If this is so, then
      // this means a WSARecv call just completed so update the BytesRECV field
      // with the BytesTransferred value from the completed WSARecv() call.

      if (PerIoData->BytesRECV == 0)
      {
         PerIoData->BytesRECV = BytesTransferred;
         PerIoData->BytesSEND = 0;
      }
      else
      {
         PerIoData->BytesSEND += BytesTransferred;
      }

      if (PerIoData->BytesRECV > PerIoData->BytesSEND)
      {

         // Post another WSASend() request.
         // Since WSASend() is not gauranteed to send all of the bytes requested,
         // continue posting WSASend() calls until all received bytes are sent.

         ZeroMemory(&(PerIoData->Overlapped), sizeof(OVERLAPPED));

         PerIoData->DataBuf.buf = PerIoData->Buffer + PerIoData->BytesSEND;
         PerIoData->DataBuf.len = PerIoData->BytesRECV - PerIoData->BytesSEND;

         if (WSASend(PerHandleData->Socket, &(PerIoData->DataBuf), 1, &SendBytes, 0,
            &(PerIoData->Overlapped), NULL) == SOCKET_ERROR)
         {
            if (WSAGetLastError() != ERROR_IO_PENDING)
            {
               printf("WSASend() failed with error %d/n", WSAGetLastError());
               return 0;
            }
         }
      }
      else
      {
         PerIoData->BytesRECV = 0;

         // Now that there are no more bytes to send post another WSARecv() request.

         Flags = 0;
         ZeroMemory(&(PerIoData->Overlapped), sizeof(OVERLAPPED));

         PerIoData->DataBuf.len = DATA_BUFSIZE;
         PerIoData->DataBuf.buf = PerIoData->Buffer;

         if (WSARecv(PerHandleData->Socket, &(PerIoData->DataBuf), 1, &RecvBytes, &Flags,
            &(PerIoData->Overlapped), NULL) == SOCKET_ERROR)
         {
            if (WSAGetLastError() != ERROR_IO_PENDING)
            {
               printf("WSARecv() failed with error %d/n", WSAGetLastError());
               return 0;
            }
         }
      }
   }
}