[英]Zombie process is not cleanup with waitpid call
我正在用 htop 观察进程,我看到即使我用 waitpid 调用进行清理,子进程仍保持为僵尸状态。 知道为什么会发生这种情况吗?
非常感谢!
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <signal.h>
void child_signal_handler(int signal) {
printf("Someone is stabbed me with signal %d\n", signal);
}
int main(int argc, char** argv)
{
const pid_t child = fork();
if (child == 0) {
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sa.sa_handler = &child_signal_handler;
sigaction(SIGTERM, &sa, NULL);
printf("Child is started in busy loop\n");
while (true)
;
} else {
const int mercy_period = 3;
printf("Parent is angry and gonna kill his child in %d sec\n", mercy_period);
sleep(mercy_period);
kill(child, SIGTERM);
// clean-up zombie child process as it is terminated before we can wait on
// it
int status = 0;
while(waitpid(-1, &status, WNOHANG) > 0);
}
return EXIT_SUCCESS;
}
waitpid glibc 实现注释
如果 PID 为 (pid_t) -1,则匹配任何进程。 如果在 OPTIONS 中设置了 WNOHANG 位,并且该孩子尚未死亡,则返回 (pid_t) 0。
当0 > 0
为假时,while 循环显然会立即退出。
将else
和信号更改为SIGKILL
} else {
const int mercy_period = 3;
printf("Parent is angry and gonna kill his child in %d sec\n", mercy_period);
sleep(mercy_period);
kill(child, SIGKILL);
int status = 0;
pid_t pid = waitpid(-1, &status, WNOHANG);
while(!pid) {
pid = waitpid(-1, &status, WNOHANG);
printf("%d\n", pid);
}
}
经过几次尝试后, waitpid
将返回子进程的 pid。 成功。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.