//////////////////////////////////////////////////////////
// initsock.h檔案

#include <winsock2.h>
#pragma comment(lib, "WS2_32")	// 連結到WS2_32.lib

class CInitSock		
{
public:
	CInitSock(BYTE minorVer = 2, BYTE majorVer = 2)
	{
		// 初始化WS2_32.dll
		WSADATA wsaData;
		WORD sockVersion = MAKEWORD(minorVer, majorVer);
		if(::WSAStartup(sockVersion, &wsaData) != 0)
		{
			exit(0);
		}
	}
	~CInitSock()
	{	
		::WSACleanup();	
	}
};
 

/////////////////////////////////////////////////
// IOCPDemo.cpp檔案			除錯通過


#include "initsock.h"
#include <stdio.h>
#include <windows.h>

// 初始化Winsock庫
CInitSock theSock;

#define BUFFER_SIZE 1024

typedef struct _PER_HANDLE_DATA		// per-handle資料
{
	SOCKET s;			// 對應的套節字控制代碼
	sockaddr_in addr;	// 客戶方地址
} PER_HANDLE_DATA, *PPER_HANDLE_DATA;


typedef struct _PER_IO_DATA			// per-I/O資料
{
	OVERLAPPED ol;			// 重疊結構
	char buf[BUFFER_SIZE];	// 資料緩衝區
	int nOperationType;		// 操作型別
#define OP_READ   1
#define OP_WRITE  2
#define OP_ACCEPT 3
} PER_IO_DATA, *PPER_IO_DATA;


DWORD WINAPI ServerThread(LPVOID lpParam)
{
	// 得到完成埠物件控制代碼
	HANDLE hCompletion = (HANDLE)lpParam;

	DWORD dwTrans;
	PPER_HANDLE_DATA pPerHandle;
	PPER_IO_DATA pPerIO;
	while(TRUE)
	{
		// 在關聯到此完成埠的所有套節字上等待I/O完成
		BOOL bOK = ::GetQueuedCompletionStatus(hCompletion, 
			&dwTrans, (LPDWORD)&pPerHandle, (LPOVERLAPPED*)&pPerIO, WSA_INFINITE);
		if(!bOK)						// 在此套節字上有錯誤發生
		{
			::closesocket(pPerHandle->s);
			::GlobalFree(pPerHandle);
			::GlobalFree(pPerIO);
			continue;
		}
		
		if(dwTrans == 0 &&				// 套節字被對方關閉
			(pPerIO->nOperationType == OP_READ || pPerIO->nOperationType == OP_WRITE))	
			
		{
			::closesocket(pPerHandle->s);
			::GlobalFree(pPerHandle);
			::GlobalFree(pPerIO);
			continue;
		}

		switch(pPerIO->nOperationType)	// 通過per-I/O資料中的nOperationType域檢視什麼I/O請求完成了
		{
		case OP_READ:	// 完成一個接收請求
			{
				static int count=1;
				pPerIO->buf[dwTrans] = '\0';
				//printf(pPerIO -> buf);
				printf("第%d次接收到資料為:%s\n",count++,pPerIO->buf);
				
				// 繼續投遞接收I/O請求
				WSABUF buf;
				buf.buf = pPerIO->buf ;
				buf.len = BUFFER_SIZE;
				pPerIO->nOperationType = OP_READ;

				DWORD nFlags = 0;
				::WSARecv(pPerHandle->s, &buf, 1, &dwTrans, &nFlags, &pPerIO->ol, NULL);
			}
			break;
		case OP_WRITE: // 本例中沒有投遞這些型別的I/O請求
		case OP_ACCEPT:
			break;
		}
	}
	return 0;
}


void main()
{
	int nPort = 9090;
	// 建立完成埠物件，建立工作執行緒處理完成埠物件中事件
	HANDLE hCompletion = ::CreateIoCompletionPort(INVALID_HANDLE_VALUE, 0, 0, 0);

	SYSTEM_INFO siSys;
	//獲取CPU數目
	GetSystemInfo(&siSys);
	//建立一定數目的工作者執行緒，本例中以一個處理器一個執行緒搭配
	for(int i = 0; i<(int)siSys.dwNumberOfProcessors*2; i++)//NumberOfProcessors
	{
		::CreateThread(NULL, 0, ServerThread, (LPVOID)hCompletion, 0, 0);
	}
	
	// 建立監聽套節字，繫結到本地地址，開始監聽
	SOCKET sListen = ::socket(AF_INET, SOCK_STREAM, 0);
	SOCKADDR_IN si;
	si.sin_family = AF_INET;
	si.sin_port = ::ntohs(nPort);
	si.sin_addr.S_un.S_addr = INADDR_ANY;
	::bind(sListen, (sockaddr*)&si, sizeof(si));
	::listen(sListen, 5);

	// 迴圈處理到來的連線
	while(TRUE)
	{
		// 等待接受未決的連線請求
		SOCKADDR_IN saRemote;
		int nRemoteLen = sizeof(saRemote);
		SOCKET sNew = ::accept(sListen, (sockaddr*)&saRemote, &nRemoteLen);

		// 接受到新連線之後，為它建立一個per-handle資料，並將它們關聯到完成埠物件。
		PPER_HANDLE_DATA pPerHandle = 
							(PPER_HANDLE_DATA)::GlobalAlloc(GPTR, sizeof(PER_HANDLE_DATA));
		pPerHandle->s = sNew;
		memcpy(&pPerHandle->addr, &saRemote, nRemoteLen);
		::CreateIoCompletionPort((HANDLE)pPerHandle->s, hCompletion, (DWORD)pPerHandle, 0);
	
		// 投遞一個接收請求
		PPER_IO_DATA pPerIO = (PPER_IO_DATA)::GlobalAlloc(GPTR, sizeof(PER_IO_DATA));
		pPerIO->nOperationType = OP_READ;
		WSABUF buf;
		buf.buf = pPerIO->buf;
		buf.len = BUFFER_SIZE;	
		DWORD dwRecv;
		DWORD dwFlags = 0;
		::WSARecv(pPerHandle->s, &buf, 1, &dwRecv, &dwFlags, &pPerIO->ol, NULL);
	}
}