SIGKILL信号总是产生zombie进程，该怎样避免？

dyte200

编写的程序用了SIGKILL信号，但总是产生zombie进程。设置：
struct sigaction act;
act.sa_handler = SIG_IGN;
sigemptyset (&act.sa_mask);
act.sa_flags = SA_NOCLDWAIT;         
sigaction (SIGCHLD, &act, NULL);
只能消除其它信号产生的zombie进程，对SIGKILL产生的zombie进程也无济于事。

zhllg

zombie一定要wait的
为SIGCHLD注册一个handler

2. void sigchld_handler(int s){
3.        while(waitpid(-1, NULL, WNOHANG) > 0);
4. }

复制代码

daemeon

直接注册成SIG_IGN就行了

MMMIX

SIGKILL 信号可以被忽略吗?

参看 signal(7)

daemeon

是父进程将SIGCHLD注册成SIG_IGN

zhllg

from man sigaction
POSIX.1-1990  disallowed setting the action for SIGCHLD to SIG_IGN.  POSIX.1-2001 allows this pos-
       sibility, so that ignoring SIGCHLD can be used to prevent the creation of zombies  (see  wait(2)).
       Nevertheless,  the historical BSD and System V behaviours for ignoring SIGCHLD differ, so that the
       only completely portable method of ensuring that terminated children do not become zombies  is  to
       catch the SIGCHLD signal and perform a wait(2) or similar.

daemeon

thanks