VisualEleven你好，请问重叠 io有关问题（代码是出自你博客下的）

VisualEleven你好，请教重叠 io问题（代码是出自你博客上的）
typedef enum _OPERATION_INFO
{
OP_NULL,
OP_READ,
OP_WRITE
}OPERATIONINFO

以上这个结构体是你定义的，我用 vs2008搜了一下关于这个结构体的引用。

Searching for 'nOpType'...
E:\c++\fff\ovlapaped.cpp(44): nOpType = OP_NULL;
E:\c++\fff\ovlapaped.cpp(52): OPERATIONINFO nOpType;
E:\c++\fff\ovlapaped.cpp(143): g_ol[g_nIndex]->nOpType = OP_READ;
E:\c++\fff\ovlapaped.cpp(193): switch(g_ol[dwIndex]->nOpType)
E:\c++\fff\ovlapaped.cpp(198): g_ol[dwIndex]->nOpType = OP_WRITE;
E:\c++\fff\ovlapaped.cpp(213): g_ol[dwIndex]->nOpType = OP_READ;
The file 'E:\c++\fff\Debug\fff_manifest.rc' is unicode and cannot be read.
6 occurrence(s) have been found.

发现： g_ol[g_nIndex]->nOpType 这个东西，谁来对其赋值呢？（或者说，谁来修改它的值呢？）

几乎没有。为什么可以根据它，用switch 进行判断是否是可读，可写呢？

期盼你的回复，谢谢了.

C/C++ code


// NetWork.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <Winsock2.h>
#include <Windows.h>
#include <process.h>
#pragma comment(lib, "WS2_32.lib")

#define MAX_BUFFER    256
#define MAX_TIMEOUT 1000

typedef enum _OPERATION_INFO
{
    OP_NULL,
    OP_READ,
    OP_WRITE
}OPERATIONINFO;

typedef struct _OVERLAPPED_INFO_
{    
public:
    _OVERLAPPED_INFO_()
    {
        Clean();
    }
    ~_OVERLAPPED_INFO_()
    {
        Clean();
    }
protected:
    void Clean()
    {
        ol.hEvent = NULL;
        sock = INVALID_SOCKET;
        memset(&addr, 0, sizeof(addr));
        addr.sin_addr.S_un.S_addr = INADDR_ANY;
        addr.sin_family = AF_INET;
        addr.sin_port = htons(0);
        wsaBuf.buf = szBuf;
        wsaBuf.len = MAX_BUFFER;
        memset(szBuf, 0, sizeof(szBuf));
        nOpType = OP_NULL;
    }
public:
    WSAOVERLAPPED ol;
    SOCKET sock;
    SOCKADDR_IN addr;
    WSABUF wsaBuf;
    char szBuf[MAX_BUFFER];
    OPERATIONINFO nOpType;
}OVERLAPPEDINFO, *POVERLAPPEDINFO;

WSAEVENT g_event[WSA_MAXIMUM_WAIT_EVENTS] = {0};
OVERLAPPEDINFO* g_ol[WSA_MAXIMUM_WAIT_EVENTS] = {0};
int g_nIndex = 0;
BOOL g_bExitThread = FALSE;

unsigned __stdcall ThreadProc(LPVOID lParam);

int _tmain(int argc, _TCHAR* argv[])
{
    WSADATA wsaData;
    if(0 != WSAStartup(MAKEWORD(2, 2), &wsaData))
    {
        printf("WSAStartup failed with error code: %d/n", GetLastError());
        return EXIT_FAILURE;
    }
    if(2 != HIBYTE(wsaData.wVersion) || 2 != LOBYTE(wsaData.wVersion))
    {
        printf("Socket version not supported./n");
        WSACleanup();
        return EXIT_FAILURE;
    }
    SOCKET sListen = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
    if(INVALID_SOCKET == sListen)
    {
        printf("socket failed with error code: %d/n", WSAGetLastError());
        WSACleanup();
        return EXIT_FAILURE;
    }
    SOCKADDR_IN addr = {0};
    addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
    addr.sin_family = AF_INET;
    addr.sin_port = htons(5050);
    if(SOCKET_ERROR == bind(sListen, (LPSOCKADDR)&addr, sizeof(addr)))
    {
        printf("bind failed with error code: %d/n", WSAGetLastError());
        closesocket(sListen);
        sListen = INVALID_SOCKET;
        WSACleanup();
        return EXIT_FAILURE;
    }
    if(SOCKET_ERROR == listen(sListen, 5))
    {
        printf("listen failed with error code: %d/n", WSAGetLastError());
        closesocket(sListen);
        sListen = INVALID_SOCKET;
        WSACleanup();
        return EXIT_FAILURE;
    }
    HANDLE hThread = (HANDLE)_beginthreadex(NULL, 0, ThreadProc, NULL, 0, NULL);
    if(NULL == hThread)
    {
        printf("_beginthreadex failed with error code: %d/n", GetLastError());
        closesocket(sListen);
        sListen = INVALID_SOCKET;
        WSACleanup();
        return EXIT_FAILURE;
    }
    
    printf("Server start listen and wait for client to connect .../n");

    SOCKADDR_IN remote = {0};
    int len = sizeof(remote);

    while(TRUE)
    {
        if(g_nIndex >= WSA_MAXIMUM_WAIT_EVENTS)
        {
            printf("Too many connect, wait for disconnect .../n");
            continue;
        }
        SOCKET sNew = accept(sListen, (LPSOCKADDR)&remote, &len);
        if(INVALID_SOCKET == sNew)
        {
            printf("accept failed with error code: %d/n", WSAGetLastError());
            continue;
        }
        printf("<IP: %s, Port: %d> client come in./n", inet_ntoa(remote.sin_addr), ntohs(remote.sin_port));
        DWORD dwTrans = 0;
        DWORD dwFlags = 0;
        g_ol[g_nIndex] = new OVERLAPPEDINFO;
        g_ol[g_nIndex]->sock = sNew;
        memcpy(&g_ol[g_nIndex]->addr, &remote, sizeof(remote));
        g_event[g_nIndex] = g_ol[g_nIndex]->ol.hEvent = WSACreateEvent();
        g_ol[g_nIndex]->nOpType = OP_READ;
        if(SOCKET_ERROR == WSARecv(g_ol[g_nIndex]->sock, &(g_ol[g_nIndex]->wsaBuf), 1, &dwTrans, &dwFlags, (LPWSAOVERLAPPED)&(g_ol[g_nIndex]->ol), NULL))
        {
            if(ERROR_IO_PENDING != WSAGetLastError())
            {
                printf("WSARecv failed with error code: %d/n", WSAGetLastError());
                closesocket(g_ol[g_nIndex]->sock);
                delete g_ol[g_nIndex];
                g_ol[g_nIndex] = NULL;
                continue;
            }
        }
        g_nIndex++;
    }
    // End of thread and exit process
    g_bExitThread = TRUE; // Exit thread.
    WaitForSingleObject(hThread, INFINITE);
    CloseHandle(hThread);

    WSACleanup();
    return 0;
}

unsigned __stdcall ThreadProc(LPVOID lParam)
{
    while(!g_bExitThread)
    {
        DWORD dwTrans = 0;
        DWORD dwFlags = 0;
        DWORD dwIndex = WSAWaitForMultipleEvents(g_nIndex, g_event, FALSE, MAX_TIMEOUT, FALSE);
        if(WSA_WAIT_FAILED == dwIndex || WSA_WAIT_TIMEOUT == dwIndex)
        {
            continue;
        }
        
        dwIndex -= WSA_WAIT_EVENT_0;
        for(int i = dwIndex; i < g_nIndex; i++)
        {
            dwIndex = WSAWaitForMultipleEvents(1, &g_event[dwIndex], TRUE, INFINITE, FALSE);
            if(WSA_WAIT_FAILED == dwIndex)
            {
                continue;
            }
            dwIndex -= WSA_WAIT_EVENT_0;
            WSAResetEvent(g_event[dwIndex]);
            BOOL bRet = WSAGetOverlappedResult(g_ol[dwIndex]->sock, &(g_ol[dwIndex]->ol), &dwTrans, FALSE, &dwFlags);
            if(bRet)
            {
                if(dwTrans > 0)
                {
                    switch(g_ol[dwIndex]->nOpType)
                    {
                    case OP_READ:
                        {
                            printf("recv client <%s:%d> data: %s/n", inet_ntoa(g_ol[dwIndex]->addr.sin_addr), ntohs(g_ol[dwIndex]->addr.sin_port), g_ol[dwIndex]->szBuf);
                            g_ol[dwIndex]->nOpType = OP_WRITE;
                            memset(&(g_ol[dwIndex]->ol), 0, sizeof(g_ol[dwIndex]->ol));
                            if(SOCKET_ERROR == WSASend(g_ol[dwIndex]->sock, &(g_ol[dwIndex]->wsaBuf), 1, &dwTrans, dwFlags, &(g_ol[dwIndex]->ol), NULL))
                            {
                                if(ERROR_IO_PENDING != WSAGetLastError())
                                {
                                    printf("WSASend failed with error code: %d/n", WSAGetLastError());
                                    continue;
                                }
                            }
                        }
                        break;

                    case OP_WRITE:
                        {
                            g_ol[dwIndex]->nOpType = OP_READ;
                            memset(&(g_ol[dwIndex]->ol), 0, sizeof(g_ol[dwIndex]->ol));
                            memset(g_ol[dwIndex]->szBuf, 0, sizeof(g_ol[dwIndex]->szBuf));
                            dwFlags = 0;
                            g_ol[dwIndex]->wsaBuf.buf = g_ol[dwIndex]->szBuf;
                            dwTrans = g_ol[dwIndex]->wsaBuf.len = MAX_BUFFER;
                            if(SOCKET_ERROR == WSARecv(g_ol[dwIndex]->sock, &(g_ol[dwIndex]->wsaBuf), 1, &dwTrans, &dwFlags, &(g_ol[dwIndex]->ol), NULL))
                            {
                                if(ERROR_IO_PENDING != WSAGetLastError())
                                {
                                    printf("WSARecv failed with error code: %d/n", WSAGetLastError());
                                    continue;
                                }
                            }
                        }
                        break;

                    default:
                        break;
                    }                
                }
                else
                {
                    printf("client <%s : %d> leave./n", inet_ntoa(g_ol[dwIndex]->addr.sin_addr), ntohs(g_ol[dwIndex]->addr.sin_port));
                    closesocket(g_ol[dwIndex]->sock);
                    WSACloseEvent(g_event[dwIndex]);
                    delete g_ol[dwIndex];
                    // Rebuild array
                    for(int i= dwIndex; i<g_nIndex-1; i++)
                    {
                        g_event[i] = g_event[i+1];
                        g_ol[i] = g_ol[i+1];
                    }
                    g_nIndex--;
                }
            }
            else
            {
                printf("WSAGetOverlappedResult failed with error: %d/n", WSAGetLastError());
            }
        }
    }
    printf("Server to exit ... /n");

    return 0;
}

VisualEleven你好，请问重叠 io有关问题（代码是出自你博客下的）

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