path purpose//Re：[patch]fork: subprocess quit when parent died

[李林哲]

Thanks for reply.


This patch is solving the problem that the sub process (worker process) will not quit when master process quits on SIGKILL. which will be done by OS (especially Linux) when system meet OOM.


I've found a bug, and will send a new patch for comment.





------------------------------------------------------------------
发件人：Maxim Dounin <mdounin at mdounin.ru>
发送时间：2016年10月12日(星期三) 22:22
收件人：nginx-devel <nginx-devel at nginx.org>; 李林哲 <llz at antiy.cn>
主　题：Re: [patch]fork: subprocess quit when parent died


Hello!

On Wed, Oct 12, 2016 at 08:44:25PM +0800, 李林哲 wrote:

> # HG changeset patch
> # User lilinzhe <llz at antiy.cn>
> # Date 1476275566 -28800
> # Node ID 07d294d39cc6ec07769c1a72d5ee9b7da27b9ce1
> # Parent  7cdf69d012f02a80c94d930b29c71847e203e4d6
> fork: subprocess quit when parent died
> 
> diff -r 7cdf69d012f0 -r 07d294d39cc6 auto/os/linux
> --- a/auto/os/linux Tue Oct 11 18:03:01 2016 +0300
> +++ b/auto/os/linux Wed Oct 12 20:32:46 2016 +0800
> @@ -157,6 +157,18 @@
>  . auto/feature
>  
>  
> +# prctl(PR_SET_PDEATHSIG)
> +
> +ngx_feature="prctl(PR_SET_PDEATHSIG)"
> +ngx_feature_name="NGX_HAVE_PR_SET_PDEATHSIG"
> +ngx_feature_run=yes
> +ngx_feature_incs="#include <sys/prctl.h>
> +                  #include <signal.h>"
> +ngx_feature_path=
> +ngx_feature_libs=
> +ngx_feature_test="if (prctl(PR_SET_PDEATHSIG, SIGKILL, 0, 0, 0) == -1) return 1"
> +. auto/feature
> +
>  # sched_setaffinity()
>  
>  ngx_feature="sched_setaffinity()"
> diff -r 7cdf69d012f0 -r 07d294d39cc6 src/os/unix/ngx_daemon.c
> --- a/src/os/unix/ngx_daemon.c Tue Oct 11 18:03:01 2016 +0300
> +++ b/src/os/unix/ngx_daemon.c Wed Oct 12 20:32:46 2016 +0800
> @@ -26,6 +26,13 @@
>          exit(0);
>      }
>  
> +    #if(NGX_HAVE_PR_SET_PDEATHSIG)
> +        if(prctl(PR_SET_PDEATHSIG, SIGTERM, 0,0,0) == -1){
> +            ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "prctl PR_SET_PDEATHSIG failed");
> +            return NGX_ERROR;
> +        }
> +    #endif
> +
>      ngx_pid = ngx_getpid();
>  
>      if (setsid() == -1) {
> diff -r 7cdf69d012f0 -r 07d294d39cc6 src/os/unix/ngx_process.c
> --- a/src/os/unix/ngx_process.c Tue Oct 11 18:03:01 2016 +0300
> +++ b/src/os/unix/ngx_process.c Wed Oct 12 20:32:46 2016 +0800
> @@ -195,6 +195,13 @@
>  
>      case 0:
>          ngx_pid = ngx_getpid();
> +
> +        #if(NGX_HAVE_PR_SET_PDEATHSIG)
> +            if(prctl(PR_SET_PDEATHSIG, SIGTERM, 0,0,0) == -1){
> +                ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_errno, "prctl PR_SET_PDEATHSIG failed");
> +                return NGX_ERROR;
> +            }
> +        #endif
>          proc(cycle, data);
>          break;

It is not clear what problem you are trying to solve.

-- 
Maxim Dounin
http://nginx.org/