[PATCH 1/1] os: added the -sigstop option for Upstart (or equivalent) startup.

[Peter Hutterer]

On Wed, Jul 14, 2010 at 11:26:43AM +0300, Oliver McFadden wrote:
> This is very similar to the RunFromSmartParent (implicit) option, except
> we do not send the signal to our parent process, but our own process
> instead, and that signal is SIGSTOP, not SIGUSR1.
> 
> Upstart or a similar equivalent program will detect this, realize that
> we are ready to accept clients now, send us SIGCONT and move our job
> status from SPAWNED to RUNNING.
> 
> Signed-off-by: Oliver McFadden <oliver.mcfadden at nokia.com>
> ---
>  include/opaque.h |    1 +
>  os/connection.c  |    5 +++++
>  os/utils.c       |    5 +++++
>  3 files changed, 11 insertions(+), 0 deletions(-)
> 
> diff --git a/include/opaque.h b/include/opaque.h
> index b3c7c70..dfe440c 100644
> --- a/include/opaque.h
> +++ b/include/opaque.h
> @@ -55,6 +55,7 @@ extern _X_EXPORT int defaultBackingStore;
>  extern _X_EXPORT Bool disableBackingStore;
>  extern _X_EXPORT Bool enableBackingStore;
>  extern _X_EXPORT Bool PartialNetwork;
> +extern _X_EXPORT Bool RunFromSigStopParent;
>  #ifndef NOLOGOHACK
>  extern _X_EXPORT int logoScreenSaver;
>  #endif
> diff --git a/os/connection.c b/os/connection.c
> index c143fb6..c596731 100644
> --- a/os/connection.c
> +++ b/os/connection.c
> @@ -146,6 +146,8 @@ Bool NewOutputPending;		/* not yet attempted to write some new output */
>  Bool AnyClientsWriteBlocked;	/* true if some client blocked on write */
>  
>  static Bool RunFromSmartParent;	/* send SIGUSR1 to parent process */
> +Bool RunFromSigStopParent;	/* send SIGSTOP to our own process; Upstart (or
> +				   equivalent) will send SIGCONT back. */
>  Bool PartialNetwork;	/* continue even if unable to bind all addrs */
>  static Pid_t ParentProcess;
>  
> @@ -357,6 +359,9 @@ NotifyParentProcess(void)
>  	    kill (ParentProcess, SIGUSR1);
>  	}
>      }
> +    if (RunFromSigStopParent) {
> +	raise (SIGSTOP);
> +    }
>  #endif
>  }
>  
> diff --git a/os/utils.c b/os/utils.c
> index 51455cc..f30674b 100644
> --- a/os/utils.c
> +++ b/os/utils.c
> @@ -527,6 +527,7 @@ void UseMsg(void)
>  #endif
>      ErrorF("-dumbSched             Disable smart scheduling, enable old behavior\n");
>      ErrorF("-schedInterval int     Set scheduler interval in msec\n");
> +    ErrorF("-sigstop               Enable SIGSTOP based startup\n");
>      ErrorF("+extension name        Enable extension\n");
>      ErrorF("-extension name        Disable extension\n");
>  #ifdef XDMCP
> @@ -922,6 +923,10 @@ ProcessCommandLine(int argc, char *argv[])
>  	    else
>  		UseMsg ();
>  	}
> +	else if ( strcmp( argv[i], "-sigstop") == 0)
> +	{
> +	    RunFromSigStopParent = TRUE;
> +	}
>  	else if ( strcmp( argv[i], "+extension") == 0)
>  	{
>  	    if (++i < argc)
> -- 
> 1.7.1.245.g7c42e

Acked-by: Peter Hutterer <peter.hutterer at who-t.net>

Cheers,
  Peter