SIGINT上的C ++程序内存泄漏

Question

我有一个程序，用作套接字客户端，这里是代码

#include <stdio.h>
#include <signal.h>
#include <iostream>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <sys/socket.h>
#include <netdb.h>

using namespace std;

void signalHandler(const int signal) {
    cout << "SIGINT handled" << endl;
    exit(EXIT_SUCCESS);
}

void error(const char *msg) {
    perror(msg);
    exit(0);
}

const string readStr(int descriptor) {
    int n = 0;
    string cmd = "";

    char buffer[256];
    memset(buffer, 0, sizeof(buffer));

    while ((n = read(descriptor, buffer, 255)) != 0) {
        if (n < 0) {
            error("Error reading string");
        }

        // full string - just copy
        if (n == 255) {
            cmd += buffer;
            memset(buffer, 0, sizeof(buffer));
        }
        else {
            cmd += buffer;
            break;
        }
    }

    return cmd;
}

int main(int argc, char** argv) {
    signal(SIGINT, signalHandler);

    int fd, port = (argc >= 3 ? atoi(argv[2]) : 11212), n;
    fd = socket(AF_INET, SOCK_STREAM, 0);
    if (fd < 0) {
        error("ERROR opening socket");
    }

    struct hostent *server = (argc >= 2 ? gethostbyname(argv[1]) : gethostbyname("localhost"));
    if (server == NULL) {
        error("ERROR no such host");
    }

    struct sockaddr_in addr;
    memset(&addr, 0, sizeof(addr));

    addr.sin_family = AF_INET;
    bcopy(server->h_addr, &addr.sin_addr.s_addr, server->h_length);
    addr.sin_port = htons(port);

    if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
        error("ERROR connecting");
    }

    string tmp;
    while (1) {
        cout << "Please enter the message: \n< " << flush;
        tmp = readStr(0);
        n = send(fd, tmp.c_str(), tmp.size(), 0);
        if (n < 0) {
            perror("ERROR writing to socket");
        }

        tmp = readStr(fd);
        cout << "> " << tmp << endl;
    }
    close(fd);

    return EXIT_SUCCESS;
}

当我发送SIGNINT来处理（CTRL + C）valgrind时说：

^ CSIGINT已处理== 3798 ==== 3798 ==堆摘要：== 3798 ==在出口处使用：1块中39个字节== 3798 ==总堆使用量：45个分配，44个释放，4,778个字节分配== 3798 ==== 3798 == 1个丢失记录中的1个块中有39个字节可能丢失== 3798 == at 0x402471C：运算符new（unsigned int）（vg_replace_malloc.c：255）== 3798 ==通过0x40DBB64：std :: string :: _ Rep :: _ S_create（unsigned int，unsigned int，std :: allocator const＆）（在/usr/lib/libstdc++.so.6.0.15）== 3798 ==通过0x1BFF403：???== 3798 ==== 3798 ==泄漏摘要：== 3798 ==绝对丢失：0字节，位于0块中== 3798 ==间接丢失：0个字节（0块）== 3798 ==可能丢失：1个块中39个字节== 3798 ==仍可到达：0字节，共0块== 3798 ==已抑制：0字节，0块== 3798 ==== 3798 ==有关检测到的和抑制的错误的计数，请重新运行：-v== 3798 ==错误摘要：来自1个上下文的1个错误（禁止显示：9个中的20个）

如果程序正确退出，例如，如果将while(1)换成int i = 0; while(i++ <= 2)，则没有内存泄漏

所以有人可以帮我解决这个问题吗？

Answer 1

[当从信号处理程序中调用std::exit时，不会取消堆栈，并且不会破坏std::string中的tmp对象main之类的局部变量。