Re: execve issues, and execve with cygrunsrv

[Daniel Pocock <daniel at pocock dot com dot au>]

Corinna Vinschen wrote:
> On Apr  2 16:21, Daniel Pocock wrote:
>   
> > Corinna Vinschen wrote:
> >     
> > > Did you try?
> > >   
> > >       
> > I have now had a chance to try it under cygrunsrv from Cygwin 1.5.25 and 1.7
> >
> > Under 1.5.25, it doesn't work because of the sockets issue
> >
> > Under 1.7, a new issue is revealed: execve doesn't maintain the same  
> > process ID, so cygrunsrv thinks the service has actually stopped, and  
> > the cygrunsrv process exits.  This is obviously quite bad.
> >     
>
> Huh?  The *Windows* PID is not the same after an exec, but the
> Cygwin PID is maintained after an exec.  Try this:
>
>   
cygrunsrv definitely stays running when I start gmond.  It stops 
immediately after the execve call - it thinks the process has stopped, 
but in fact a new gmond is running with a new Windows PID.  I am using 
the -x option to cygrunsrv and the -f (foreground) and -p (pidfile) 
options to gmond.  Which PID does cygrunsrv look for?

>     #include <stdio.h>
>     #include <unistd.h>
>     #include <sys/types.h>
>     #include <sys/wait.h>
>     #include <windows.h>
>
>     int main(int argc, char **argv)
>     {
>       int status;
>
>       if (argc > 1)
> 	{
> 	  printf ("Execed Child: Cygwin: %d Windows: %lu\n",
> 		  getpid (), GetCurrentProcessId ());
> 	  return 0;
> 	}
>       printf ("Parent: Cygwin: %d Windows: %lu\n",
> 	      getpid (), GetCurrentProcessId ());
>       switch (fork ())
> 	{
> 	case 0:
> 	  printf ("Forked Child: Cygwin: %d Windows: %lu\n",
> 		  getpid (), GetCurrentProcessId ());
> 	  execl ("./x", "x", "child", NULL);
> 	  break;
> 	default:
> 	  break;
> 	}
>       wait (&status);
>       return 0;
>     }
>
>
>
> Corinna
>
>   

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