Re: [PATCH 10/12] libxl: fork: Break out sigchld_installhandler_core

[Ian Campbell <Ian.Campbell@citrix.com>]

On Fri, 2014-01-17 at 16:24 +0000, Ian Jackson wrote:
> Pure code motion.  This is going to make the final substantive patch
> easier to read.
> 
> Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
> Cc: Jim Fehlig <jfehlig@suse.com>

Acked-by: Ian Campbell <Ian.Campbell@citrix.com>

> ---
>  tools/libxl/libxl_fork.c |   38 ++++++++++++++++++++++----------------
>  1 file changed, 22 insertions(+), 16 deletions(-)
> 
> diff --git a/tools/libxl/libxl_fork.c b/tools/libxl/libxl_fork.c
> index a15af8e..ce8e8eb 100644
> --- a/tools/libxl/libxl_fork.c
> +++ b/tools/libxl/libxl_fork.c
> @@ -194,6 +194,27 @@ static void sigchld_removehandler_core(void)
>      sigchld_owner = 0;
>  }
>  
> +static void sigchld_installhandler_core(libxl__gc *gc)
> +{
> +    struct sigaction ours;
> +    int r;
> +
> +    assert(!sigchld_owner);
> +    sigchld_owner = CTX;
> +
> +    memset(&ours,0,sizeof(ours));
> +    ours.sa_handler = sigchld_handler;
> +    sigemptyset(&ours.sa_mask);
> +    ours.sa_flags = SA_NOCLDSTOP | SA_RESTART;
> +    r = sigaction(SIGCHLD, &ours, &sigchld_saved_action);
> +    assert(!r);
> +
> +    assert(((void)"application must negotiate with libxl about SIGCHLD",
> +            !(sigchld_saved_action.sa_flags & SA_SIGINFO) &&
> +            (sigchld_saved_action.sa_handler == SIG_DFL ||
> +             sigchld_saved_action.sa_handler == SIG_IGN)));
> +}
> +
>  void libxl__sigchld_notneeded(libxl__gc *gc) /* non-reentrant, idempotent */
>  {
>      int rc;
> @@ -236,22 +257,7 @@ int libxl__sigchld_needed(libxl__gc *gc) /* non-reentrant, idempotent */
>  
>      atfork_lock();
>      if (sigchld_owner != CTX) {
> -        struct sigaction ours;
> -
> -        assert(!sigchld_owner);
> -        sigchld_owner = CTX;
> -
> -        memset(&ours,0,sizeof(ours));
> -        ours.sa_handler = sigchld_handler;
> -        sigemptyset(&ours.sa_mask);
> -        ours.sa_flags = SA_NOCLDSTOP | SA_RESTART;
> -        r = sigaction(SIGCHLD, &ours, &sigchld_saved_action);
> -        assert(!r);
> -
> -        assert(((void)"application must negotiate with libxl about SIGCHLD",
> -                !(sigchld_saved_action.sa_flags & SA_SIGINFO) &&
> -                (sigchld_saved_action.sa_handler == SIG_DFL ||
> -                 sigchld_saved_action.sa_handler == SIG_IGN)));
> +        sigchld_installhandler_core(gc);
>      }
>      atfork_unlock();
>