c++ - 为什么socket在gdb下会失败？

Question

socket 在 gdb 下突然崩溃(但正常工作)。这只会在我初始化 winsock 时发生。非常感谢任何帮助。

#include <stdlib.h>
#include <stdio.h>
#include <locale.h>

#include <winsock2.h>
#include <Iphlpapi.h>
#ifdef _MSC_VER
    #pragma comment(lib, "ws2_32.lib")
    #pragma comment(lib, "IPHLPAPI.lib")
#endif
#include <windows.h>

unsigned char Network_isInitialized_ = 0;

#define SYSTEMINFORMATION_ISNATIVEWINDOWS 1

unsigned char Network_init_(){
#if SYSTEMINFORMATION_ISNATIVEWINDOWS
    if (Network_isInitialized_){
        return Network_isInitialized_;
    }
    WSADATA wsadata;
    int error = WSAStartup(0x0202, &wsadata);
    Network_isInitialized_ = error == 0 ? 1 : 0;
    return Network_isInitialized_;
#else
    return 1;
#endif
}

void Network_shutdown_(){
#if SYSTEMINFORMATION_ISNATIVEWINDOWS
    if (Network_isInitialized_){
        WSACleanup(); //Clean up Winsock
    }
    Network_isInitialized_ = 0;
#else
    //Unix doesnt need to do anything
#endif
}


typedef struct TCP_Connection_s {
    char *name;
    int port;
    unsigned int ip;

    struct sockaddr_in *connection;
    void *ptr;
    unsigned int socket;
} TCP_Connection;

TCP_Connection* TCP_Connection_malloc(){
    TCP_Connection *connection = (TCP_Connection*)malloc(sizeof(TCP_Connection));
    memset(connection, 0, sizeof(*connection));
    connection->connection = (struct sockaddr_in*) malloc (sizeof(struct sockaddr_in));
    memset(connection->connection, 0, sizeof(*connection->connection));
    return connection;
}

TCP_Connection* myconnect(TCP_Connection *connection){
    if (connection == NULL){
        return NULL;
    }
    connection->socket = socket(AF_INET, SOCK_STREAM, 0);
    if (connection->socket+1 == 0){
        return NULL;
    }
    int ret = connect(connection->socket, (struct sockaddr *)connection->connection, sizeof(*connection->connection));
    if (ret != 0){
        return NULL;
    }
    return connection;
}

TCP_Connection* connectToHost(TCP_Connection *connection, char *address, int port){
    if (address == NULL){
        return NULL;
    }

    if (connection == NULL){
        connection = TCP_Connection_malloc();
    }

    struct hostent *he = (struct hostent *) gethostbyname(address);
    int retryCount = 5;
    while (he == NULL && retryCount > 0){
        he = (struct hostent *) gethostbyname(address);
        Sleep(2000);
        retryCount = retryCount - 1;
    }
    if (he == NULL){
        return NULL;
    }
    struct sockaddr_in temp;
    memcpy(&(temp.sin_addr), he->h_addr, he->h_length);

    connection->connection->sin_family = AF_INET;
    connection->connection->sin_addr.s_addr = INADDR_ANY;
    connection->connection->sin_port = htons(port);
    connection->port = port;

    memcpy(&(connection->connection->sin_addr), he->h_addr, he->h_length);
    return myconnect(connection);
}


int main(int argc, char *argv[]){
    //Random_seedCryptographic();
    Network_init_();
    connectToHost(NULL, "localhost", 1337);
    Network_shutdown_();
    printf("Press any key to continue...");
    fflush(0);
    getchar();
    return 0;
}

$ gdb test.exeGNU gdb (GDB) 7.3.50.20111026-cvs (cygwin-special)Copyright (C) 2011 Free Software Foundation, Inc.License GPLv3+: GNU GPL version 3 or later This is free software: you are free to change and redistribute it.There is NO WARRANTY, to the extent permitted by law.  Type "show copying"and "show warranty" for details.This GDB was configured as "i686-cygwin".For bug reporting instructions, please see:...Reading symbols from /cygdrive/c/test.exe...done.(gdb) runStarting program: /cygdrive/c/test.exe[New Thread 201280.0x60b68]dll path too long[New Thread 201280.0x304b0]warning: Could not load shared library symbols for //./globalroot/systemroot/syswow64/mswsock.dll.Do you need "set solib-search-path" or "set sysroot"?Program received signal SIGTRAP, Trace/breakpoint trap.0x3567125a in ?? () from /cygdrive/c/Windows/syswow64/mswsock.dll(gdb) bt#0  0x3567125a in ?? () from /cygdrive/c/Windows/syswow64/mswsock.dll#1  0x753b8b9d in inet_ntoa () from /cygdrive/c/Windows/syswow64/WS2_32.dll#2  0x753b8972 in inet_ntoa () from /cygdrive/c/Windows/syswow64/WS2_32.dll#3  0x753b89da in inet_ntoa () from /cygdrive/c/Windows/syswow64/WS2_32.dll#4  0x753b3d70 in WSCInstallProvider ()   from /cygdrive/c/Windows/syswow64/WS2_32.dll#5  0x00000002 in ?? ()#6  0x00000001 in ?? ()#7  0x00000000 in ?? ()(gdb)

更新:我尝试在 mingw portable 下的不同系统上编译相同的文件并且成功了。然后我尝试在我的系统上安装 mingw 并卸载 cygwin ...仍然不起作用 XD

Answer 1

那是因为 Cygwin 试图模拟 UNIX 环境，您不需要在 UNIX 上调用 WSAStartup()。 Cygwin 在后台自动执行此操作，因此您正在重复 Winsock 的初始化/清理。参见 this ，例如。