C++ kill()使Linux崩溃到登录屏幕

我的一个项目遇到了问题， 我正在用fork创建子进程，然后用kill(pid，SIGint)终止它们，然后重新启动它们 第二次中断后，Linux将崩溃到登录屏幕.所以也有可能gnome或我的窗口管理器实际上就是崩溃的东西 我不知道如何解决这个问题. 这是导致崩溃的代码

#include <iostream>
#include <signal.h>
#include <thread>

const int CHILDREN = 3;
bool is_active;

using namespace std;

void signalHandler(int signum)
{
    cout << "Interrupt signal (" << signum << ") received.\n";

    // cleanup and close up stuff here
    // terminate program

    is_active = false;
}

pid_t fork_process(int process_nr)
{
    pid_t c_pid;
    c_pid = fork();
    if (c_pid == -1)
    {
        perror("failure to fork new process");
        return -1;
    }
    else if (c_pid == 0)
    { // child process
        signal(SIGINT, signalHandler);
        is_active = true;
        while (is_active)
        {
        }
        cout << "child " << process_nr << " EXIT" << endl;
        return -1;
    }
    return c_pid;
}

pid_t restart_process(int process_nr, pid_t pid)
{
    cout << "restart process " << process_nr << endl;
    pid_t new_c_pid;
    kill(pid, SIGINT);//THIS IS WHERE THE CRASH HAPPENS

    sleep(3);

    new_c_pid = fork_process(process_nr);
    return new_c_pid;
}

int main(int argc, char const *argv[])
{
    int ret;
    pid_t c_pid[CHILDREN];

    for (int i = 0; i < CHILDREN; i++)
    {
        ret = fork_process(i);
        if (ret == -1)
            return 0;
        c_pid[i] = ret;
        cout << "parent created child " << i << " with c_pid " << c_pid[i] << endl;
    }

    int to_restart = 1;

    this_thread::sleep_for(chrono::seconds(16));

    // restart the selected process
    c_pid[to_restart] = restart_process(to_restart, c_pid[to_restart]);

    this_thread::sleep_for(chrono::seconds(16));

    // restart the selected process
    c_pid[to_restart] = restart_process(to_restart, c_pid[to_restart]);//THIS IS WHERE THE CRASH HAPPENS

    this_thread::sleep_for(chrono::seconds(16));
    return 0;
}

使用Makfile

CC = g++
CFLAGS = -Wall -g

output: main.o
    $(CC) $(CFLAGS) -o output main.o
main.o: main.cpp
    $(CC) $(CFLAGS) -c  main.cpp
clean:
    rm *.o output

谢谢你的帮助.

重新启动一次效果很好，所以我不知道调用两次会造成崩溃 我已经用gDB运行了它，并标记了崩溃发生的位置.然而，它不会立即发生，而是在执行kill()函数5秒后发生