#include?<winsock2.h>
#include?<stdio.h>
#define?PORT 5150
#define?MSGSIZE 1024
#pragma?comment(lib,?"ws2_32.lib")
typedef?struct
{
?WSAOVERLAPPED overlap;//為了使用重疊I/O，每一個I/O函數都要接受一個WSAOVERLAPPED結構類型的參數

?WSABUF Buffer;
?char?szMessage[MSGSIZE];
?DWORD NumberOfBytesRecvd;
?DWORD Flags;
}PER_IO_OPERATION_DATA,?*LPPER_IO_OPERATION_DATA;
int?g_iTotalConn?=?0;
SOCKET?g_CliSocketArr[MAXIMUM_WAIT_OBJECTS];
WSAEVENT g_CliEventArr[MAXIMUM_WAIT_OBJECTS];
LPPER_IO_OPERATION_DATA g_pPerIODataArr[MAXIMUM_WAIT_OBJECTS];
DWORD WINAPI WorkerThread(LPVOID);
void?Cleanup(int);
int?main()
{
?WSADATA wsaData;
?SOCKET?sListen,?sClient;
?SOCKADDR_IN?local,?client;
?DWORD dwThreadId;
?int?iaddrSize?=?sizeof(SOCKADDR_IN);
?// Initialize Windows Socket library

?WSAStartup(0x0202,?&wsaData);
?// Create listening socket

?sListen?=?::WSASocket(AF_INET,?SOCK_STREAM,?IPPROTO_TCP,NULL,0,WSA_FLAG_OVERLAPPED);
?// 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

??sClient?=?accept(sListen,?(struct?sockaddr?*)&client,?&iaddrSize);
??printf("Accepted client:%s:%d\n",?inet_ntoa(client.sin_addr),?ntohs(client.sin_port));
??g_CliSocketArr[g_iTotalConn]?=?sClient;
??// Allocate a PER_IO_OPERATION_DATA structure

??g_pPerIODataArr[g_iTotalConn]?=?(LPPER_IO_OPERATION_DATA)HeapAlloc(
???GetProcessHeap(),
???HEAP_ZERO_MEMORY,
???sizeof(PER_IO_OPERATION_DATA));
??g_pPerIODataArr[g_iTotalConn]->Buffer.len?=?MSGSIZE;
??g_pPerIODataArr[g_iTotalConn]->Buffer.buf?=?g_pPerIODataArr[g_iTotalConn]->szMessage;
??g_CliEventArr[g_iTotalConn]?=?g_pPerIODataArr[g_iTotalConn]->overlap.hEvent?=?WSACreateEvent();
??// Launch an asynchronous operation(發起一個異步的I/O操作)

??//This function receives data from a connected socket.

??WSARecv(
???g_CliSocketArr[g_iTotalConn],//Socket的標示

???&g_pPerIODataArr[g_iTotalConn]->Buffer,//接收數據的Buffer

???1,
???&g_pPerIODataArr[g_iTotalConn]->NumberOfBytesRecvd,//Pointer to the number of bytes received by this call if the receive operation completes immediately

???&g_pPerIODataArr[g_iTotalConn]->Flags,
???&g_pPerIODataArr[g_iTotalConn]->overlap,//LPWSAOVERLAPPED結構的參數

???NULL);
??g_iTotalConn++;
?}
?closesocket(sListen);
?WSACleanup();
?return?0;
}
DWORD WINAPI WorkerThread(LPVOID lpParam)
{
?int?ret,?index;
?DWORD cbTransferred;
?while?(TRUE)
?{
??ret?=?WSAWaitForMultipleEvents(g_iTotalConn,?g_CliEventArr,?FALSE,?1000,?FALSE);
??//注意這里應該有相應的修正的地方，WSAWaitForMultipleEvents函數在fWaitAll設置成FALSE

??//的時候只能指定一個事件對象受信，解決方法使用for循環進行循環檢測

??if?(ret?==?WSA_WAIT_FAILED?||?ret?==?WSA_WAIT_TIMEOUT)
??{
???continue;
??}
??index?=?ret?-?WSA_WAIT_EVENT_0;
??WSAResetEvent(g_CliEventArr[index]);
??//獲得重疊I/O的操作的結果

??WSAGetOverlappedResult(
???g_CliSocketArr[index],
???&g_pPerIODataArr[index]->overlap,
???&cbTransferred,
???TRUE,
???&g_pPerIODataArr[g_iTotalConn]->Flags);
??if?(cbTransferred?==?0)
??{
???// The connection was closed by client

???Cleanup(index);
??}
??else
??{
???// g_pPerIODataArr[index]->szMessage contains the received data

???g_pPerIODataArr[index]->szMessage[cbTransferred]?=?'\0';
???//這個是同步的I/O的操作哦

???send(g_CliSocketArr[index],?g_pPerIODataArr[index]->szMessage,\
????cbTransferred,?0);
???// Launch another asynchronous operation

???WSARecv(
????g_CliSocketArr[index],
????&g_pPerIODataArr[index]->Buffer,
????1,
????&g_pPerIODataArr[index]->NumberOfBytesRecvd,
????&g_pPerIODataArr[index]->Flags,
????&g_pPerIODataArr[index]->overlap,
????NULL);
??}
?}
?return?0;
}
void?Cleanup(int?index)
{
?closesocket(g_CliSocketArr[index]);
?WSACloseEvent(g_CliEventArr[index]);
?HeapFree(GetProcessHeap(),?0,?g_pPerIODataArr[index]);
?if?(index?<?g_iTotalConn?-?1)
?{
??g_CliSocketArr[index]?=?g_CliSocketArr[g_iTotalConn?-?1];
??g_CliEventArr[index]?=?g_CliEventArr[g_iTotalConn?-?1];
??g_pPerIODataArr[index]?=?g_pPerIODataArr[g_iTotalConn?-?1];
?}
?g_pPerIODataArr[--g_iTotalConn]?=?NULL;
}