完成端口网上的例子很多，但觉得都挺复杂的
写了一个简化版的，方便学习，也加了注释。
有任何问题，欢迎跟我讨论。
========代码来了=========
#include <winsock2.h>
#include <mswsock.h>
#include <windows.h>
#include <iostream>
using namespace std;
int g_ThreadCount;
HANDLE g_hIOCP = INVALID_HANDLE_VALUE;
SOCKET g_ServerSocket = INVALID_SOCKET;
// Maximum Buffer Size
#define MAX_BUFF_SIZE 8192
enum IO_OPERATION{IO_READ,IO_WRITE};
struct IO_DATA{
WSAOVERLAPPED Overlapped;
char Buffer[MAX_BUFF_SIZE];
WSABUF wsabuf;
int nTotalBytes;
int nSentBytes;
IO_OPERATION opCode;
SOCKET activeSocket;
};
DWORD WINAPI WorkerThread (LPVOID WorkThreadContext) {
LPWSAOVERLAPPED lpOverlapped = NULL;
IO_DATA *lpIOContext = NULL;
WSABUF buffSend;
DWORD dwRecvNumBytes = 0;
DWORD dwSendNumBytes = 0;
DWORD dwFlags = 0;
DWORD dwIoSize = 0;
BOOL bSuccess = FALSE;
int nRet = 0;
while( 1 ) {
void * lpCompletionKey = NULL;
bSuccess = GetQueuedCompletionStatus(g_hIOCP, &dwIoSize,
(LPDWORD)&lpCompletionKey,
(LPOVERLAPPED *)&lpOverlapped,
INFINITE);
if( !bSuccess )
{
cout << "GetQueuedCompletionStatus() failed:"<<GetLastError()<<endl;
break;
}
lpIOContext = (IO_DATA *)lpOverlapped;
if(dwIoSize == 0) //socket closed?
{
cout << "Client disconnect" << endl;
closesocket(lpIOContext->activeSocket);
delete lpIOContext;
continue;
}
if(lpIOContext->opCode == IO_READ) // a read operation complete
{
lpIOContext->nTotalBytes = lpIOContext->wsabuf.len;
lpIOContext->nSentBytes = 0;
lpIOContext->opCode = IO_WRITE;
dwFlags = 0;
nRet = WSASend(
lpIOContext->activeSocket,
&lpIOContext->wsabuf, 1, &dwSendNumBytes,
dwFlags,
&(lpIOContext->Overlapped), NULL);
if( nRet == SOCKET_ERROR && (ERROR_IO_PENDING != WSAGetLastError()) ) {
cout << "WASSend Failed::Reason Code::"<< WSAGetLastError() << endl;
closesocket(lpIOContext->activeSocket);
delete lpIOContext;
continue;
}
}
else if(lpIOContext->opCode == IO_WRITE) //a write operation complete
{
lpIOContext->nSentBytes += dwIoSize;
dwFlags = 0;
if( lpIOContext->nSentBytes < lpIOContext->nTotalBytes ) {
lpIOContext->opCode = IO_WRITE;
// A Write operation has not completed yet, so post another
// Write operation to post remaining data.
buffSend.buf = lpIOContext->Buffer + lpIOContext->nSentBytes;
buffSend.len = lpIOContext->nTotalBytes - lpIOContext->nSentBytes;
nRet = WSASend (
lpIOContext->activeSocket,
&buffSend, 1, &dwSendNumBytes,
dwFlags,
&(lpIOContext->Overlapped), NULL);
if( nRet == SOCKET_ERROR && (ERROR_IO_PENDING != WSAGetLastError()) ) {
cout << "WASSend Failed::Reason Code::"<< WSAGetLastError() << endl;
closesocket(lpIOContext->activeSocket);
delete lpIOContext;
continue;
}
} else {
// Write operation completed, so post Read operation.
lpIOContext->opCode = IO_READ;
dwRecvNumBytes = 0;
dwFlags = 0;
lpIOContext->wsabuf.buf = lpIOContext->Buffer,
ZeroMemory(lpIOContext->wsabuf.buf,MAX_BUFF_SIZE);
lpIOContext->Overlapped.Internal = 0;
lpIOContext->Overlapped.InternalHigh = 0;
lpIOContext->Overlapped.Offset = 0;
lpIOContext->Overlapped.OffsetHigh = 0;
lpIOContext->Overlapped.hEvent = NULL;
lpIOContext->wsabuf.len = MAX_BUFF_SIZE;
nRet = WSARecv(
lpIOContext->activeSocket,
&lpIOContext->wsabuf, 1, &dwRecvNumBytes,
&dwFlags,
&lpIOContext->Overlapped, NULL);
if( nRet == SOCKET_ERROR && (ERROR_IO_PENDING != WSAGetLastError()) ) {
cout << "WASRecv Failed::Reason Code::"<< WSAGetLastError() << endl;
closesocket(lpIOContext->activeSocket);
delete lpIOContext;
continue;
}
}
}
}
return 0;
}
void main (int argc, char * argv[])
{
{ // Init winsock2
WSADATA wsaData;
ZeroMemory(&wsaData,sizeof(WSADATA));
int retVal = -1;
if( (retVal = WSAStartup(MAKEWORD(2,2), &wsaData)) != 0 ) {
cout << "WSAStartup Failed::Reason Code::"<< retVal << endl;
return;
}
}
{ //Create socket
g_ServerSocket = WSASocket(AF_INET,SOCK_STREAM, IPPROTO_TCP, NULL,0,WSA_FLAG_OVERLAPPED);
if( g_ServerSocket == INVALID_SOCKET ) {
cout << "Server Socket Creation Failed::Reason Code::" << WSAGetLastError() << endl;
return;
}
}
{ //bind
sockaddr_in service;
service.sin_family = AF_INET;
service.sin_addr.s_addr = htonl(INADDR_ANY);
service.sin_port = htons(5000);
int retVal = bind(g_ServerSocket,(SOCKADDR *)&service,sizeof(service));
if( retVal == SOCKET_ERROR ) {
cout << "Server Soket Bind Failed::Reason Code::"<< WSAGetLastError() << endl;
return;
}
}
{ //listen
int retVal = listen(g_ServerSocket, 8);
if( retVal == SOCKET_ERROR ) {
cout << "Server Socket Listen Failed::Reason Code::"<< WSAGetLastError() << endl;
return;
}
}
{ // Create IOCP
SYSTEM_INFO sysInfo;
ZeroMemory(&sysInfo,sizeof(SYSTEM_INFO));
GetSystemInfo(&sysInfo);
g_ThreadCount = sysInfo.dwNumberOfProcessors * 1;
g_hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE,NULL,0,g_ThreadCount);
if (g_hIOCP == NULL) {
cout << "CreateIoCompletionPort() Failed::Reason::"<< GetLastError() << endl;
return;
}
if (CreateIoCompletionPort((HANDLE)g_ServerSocket,g_hIOCP,0,0) == NULL){
cout << "Binding Server Socket to IO Completion Port Failed::Reason Code::"<< GetLastError() << endl;
return ;
}
}
{ //Create worker threads
for( DWORD dwThread=0; dwThread < g_ThreadCount; dwThread++ )
{
HANDLE hThread;
DWORD dwThreadId;
hThread = CreateThread(NULL, 0, WorkerThread, 0, 0, &dwThreadId);
CloseHandle(hThread);
}
}
{ //accept new connection
while(1)
{
SOCKET ls = accept( g_ServerSocket, NULL, NULL );
if(ls == SOCKET_ERROR) break;
cout << "Client connected." << endl;
{ //diable buffer to improve performance
int nZero = 0;
setsockopt(ls, SOL_SOCKET, SO_SNDBUF, (char *)&nZero, sizeof(nZero));
}
if (CreateIoCompletionPort((HANDLE)ls,g_hIOCP,0,0) == NULL){
cout << "Binding Client Socket to IO Completion Port Failed::Reason Code::"<< GetLastError() << endl;
closesocket(ls);
}
else { //post a recv request
IO_DATA * data = new IO_DATA;
ZeroMemory(&data->Overlapped,sizeof(data->Overlapped));
ZeroMemory(data->Buffer,sizeof(data->Buffer));
data->opCode = IO_READ;
data->nTotalBytes = 0;
data->nSentBytes = 0;
data->wsabuf.buf = data->Buffer;
data->wsabuf.len = sizeof(data->Buffer);
data->activeSocket = ls;
DWORD dwRecvNumBytes=0,dwFlags=0;
int nRet = WSARecv(ls,&data->wsabuf, 1, &dwRecvNumBytes,
&dwFlags,
&data->Overlapped, NULL);
if(nRet == SOCKET_ERROR && (ERROR_IO_PENDING != WSAGetLastError())){
cout << "WASRecv Failed::Reason Code::"<< WSAGetLastError() << endl;
closesocket(ls);
delete data;
}
}
}
}
closesocket(g_ServerSocket);
WSACleanup();
}