[IOCP] 서버 코딩 연습

// IOCP_practice.cpp: 콘솔 응용 프로그램의 진입점을 정의합니다.
// IOCP => Input/Output Completion Port
 
#include "stdafx.h"
#include <WinSock2.h>
#include <iostream>
 
#pragma comment(lib, "Ws2_32.lib")
 
#define SERVER_PORT 3500
#define MAX_BUFFER 1024
 
using namespace std;
 
struct SOCKETINFO
{
    WSAOVERLAPPED overlapped;
    WSABUF dataBuffer;
    SOCKET socket;
    char messageBuffer[MAX_BUFFER];
    int receiveBytes;
    int sendBytes;
};
 
DWORD WINAPI makeThread(LPVOID hIOCP);
 
int main()
{
    // Winsock Start - windock.dll 로드
    WSADATA WSAData;
    if (WSAStartup(MAKEWORD(2, 2), &WSAData) != 0) {
        printf("Error - Can not load 'winsock.dll' file\n");
        return 1;
    }
 
    //1. 소켓생성
    SOCKET listenSocket = WSASocket(AF_INET, SOCK_STREAM, 0, NULL, 0, WSA_FLAG_OVERLAPPED);
    if (listenSocket == INVALID_SOCKET) {
        printf("Error - Invalid socket\n");
        return 1;
    }
 
    //서버정보 객체설정
    SOCKADDR_IN serverAddr;
    memset(&serverAddr, 0, sizeof(SOCKADDR_IN));
    serverAddr.sin_family = PF_INET;
    serverAddr.sin_port = htons(SERVER_PORT);
    serverAddr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
 
    //2. 소켓 설정
    if (bind(listenSocket, (struct sockaddr*)&serverAddr, sizeof(SOCKADDR_IN)) == SOCKET_ERROR) {
        printf("Error - Fail bind\n");
        closesocket(listenSocket);
        WSACleanup();
        return 1;
    }
 
    //3. 수신대기열생성
    if (listen(listenSocket, 5) == SOCKET_ERROR) {
        printf("Error - Fail listen\n");
        closesocket(listenSocket);
        WSACleanup();
        return 1;
    }
 
    //완료 결과를 처리하는 객체 생성(IOCP)
    HANDLE hIOCP = CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, 0, 0);
    /*디바이스와 연결할 때는 다음과 같이 사용
    HANDLE IOCP = CreateIoCompletionPort(socket, hIOCP, (ULONG_PTR)session, 0);
    */
 
    // 워커스레드 생성
    // -cpu * 2개
    SYSTEM_INFO systemInfo;
    GetSystemInfo(&systemInfo);
    int threadCount = systemInfo.dwNumberOfProcessors * 2;
    unsigned long threadId;
    // 쓰레드 핸들러 선언
    HANDLE *hThread = (HANDLE *)malloc(threadCount * sizeof(HANDLE));
    // cpu 갯수 만큼 쓰레드 생성
    for (int i = 0; i < threadCount; i++) {
        hThread[i] = CreateThread(NULL, 0, makeThread, &hIOCP, 0, &threadId);
    }
 
    SOCKADDR_IN clientAddr;
    int addrLen = sizeof(SOCKADDR_IN);
    memset(&clientAddr, 0, addrLen);
    SOCKET clientSocket;
    SOCKETINFO *socketInfo;
    DWORD receiveBytes;
    DWORD flags;
 
    while (1) {
        clientSocket = accept(listenSocket, (struct sockaddr *)&clientAddr, &addrLen);
        if (clientSocket == INVALID_SOCKET) {
            printf("Error - Accept Failure\n");
            return 1;
        }
 
        socketInfo = (struct SOCKETINFO *)malloc(sizeof(struct SOCKETINFO));
        memset((void*)socketInfo, 0x00, sizeof(struct SOCKETINFO));
        socketInfo->socket = clientSocket;
        socketInfo->receiveBytes = 0;
        socketInfo->sendBytes = 0;
        socketInfo->dataBuffer.len = MAX_BUFFER;
        socketInfo->dataBuffer.buf = socketInfo->messageBuffer;
        flags = 0;
 
        hIOCP = CreateIoCompletionPort((HANDLE)clientSocket, hIOCP, (DWORD)socketInfo, 0);
 
        if (WSARecv(socketInfo->socket, &socketInfo->dataBuffer, 1,
            &receiveBytes, &flags, &(socketInfo->overlapped), NULL)) {
            if (WSAGetLastError() != WSA_IO_PENDING) {
                printf("Error - IO pending Failure\n");
                return 1;
            }
        }
    }
 
    closesocket(listenSocket);
 
    WSACleanup();
    return 0;
 
}
 
DWORD WINAPI makeThread(LPVOID hIOCP) {
    HANDLE threadHandler = *((HANDLE *)hIOCP);
    DWORD receiveBytes;
    DWORD sendBytes;
    DWORD completionKey;
    DWORD flags;
    struct SOCKETINFO *eventSocket;
    while (1)
    {
        // 입출력 완료 대기
        if (GetQueuedCompletionStatus(threadHandler, &receiveBytes, &completionKey, 
(LPOVERLAPPED *)&eventSocket, INFINITE) == 0)
        {
            printf("Error - GetQueuedCompletionStatus Failure\n");
            closesocket(eventSocket->socket);
            free(eventSocket);
            return 1;
        }
 
        eventSocket->dataBuffer.len = receiveBytes;
 
        if (receiveBytes == 0)
        {
            closesocket(eventSocket->socket);
            free(eventSocket);
            continue;
        }
        else
        {
            printf("TRACE - Receive message : %s (%d bytes)\n", eventSocket->dataBuffer.buf, 
eventSocket->dataBuffer.len);
 
            if (WSASend(eventSocket->socket, &(eventSocket->dataBuffer), 1, &sendBytes, 0, NULL, NULL) == SOCKET_ERROR)
            {
                if (WSAGetLastError() != WSA_IO_PENDING)
                {
                    printf("Error - Fail WSASend(error_code : %d)\n", WSAGetLastError());
                }
            }
 
            printf("TRACE - Send message : %s (%d bytes)\n", eventSocket->dataBuffer.buf, eventSocket->dataBuffer.len);
 
            memset(eventSocket->messageBuffer, 0x00, MAX_BUFFER);
            eventSocket->receiveBytes = 0;
            eventSocket->sendBytes = 0;
            eventSocket->dataBuffer.len = MAX_BUFFER;
            eventSocket->dataBuffer.buf = eventSocket->messageBuffer;
            flags = 0;
 
            if (WSARecv(eventSocket->socket, &(eventSocket->dataBuffer), 1, &receiveBytes,
 &flags, &eventSocket->overlapped, NULL) == SOCKET_ERROR)
            {
                if (WSAGetLastError() != WSA_IO_PENDING)
                {
                    printf("Error - Fail WSARecv(error_code : %d)\n", WSAGetLastError());
                }
            }
        }
    }
}
 
 

[코드 출저]: http://myblog.opendocs.co.kr/archives/1206

네트워크 데이터형식 변환 함수

Convert multi-byte integer types from host byte order to network byte order

htons()  : Host to network short

htonl()  : Host to network long

ntohs() : network to host short

ntohl() :  network to host long

서버의 생성 과정

socket() -> bind() -> listen() -> accept() -> read() & write() -> close()

클라이언트 생성 과정

socket() -> connect() -> read() & write() -> close()