Re: [Qemu-devel] [PATCH v6 1/5] shutdown: Simplify shutdown_signal

[Alistair Francis]

On Fri, May 5, 2017 at 12:38 PM, Eric Blake <address@hidden> wrote:
> There is no signal 0 (kill(pid, 0) has special semantics to probe whether
> a process is alive), rather than actually sending a signal 0).  So we
> can use the simpler 0, instead of -1, for our sentinel of whether a
> shutdown request due to a signal has happened.
>
> Suggested-by: Markus Armbruster <address@hidden>
> Signed-off-by: Eric Blake <address@hidden>
> Reviewed-by: Markus Armbruster <address@hidden>

Reviewed-by: Alistair Francis <address@hidden>

Thanks,

Alistair

>
> ---
> v4-v6: no change
> v3: new patch
> ---
>  vl.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/vl.c b/vl.c
> index 42d4bce..f22a3ac 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -1598,7 +1598,7 @@ void vm_state_notify(int running, RunState state)
>  }
>
>  static int reset_requested;
> -static int shutdown_requested, shutdown_signal = -1;
> +static int shutdown_requested, shutdown_signal;
>  static pid_t shutdown_pid;
>  static int powerdown_requested;
>  static int debug_requested;
> @@ -1629,7 +1629,7 @@ static int qemu_shutdown_requested(void)
>
>  static void qemu_kill_report(void)
>  {
> -    if (!qtest_driver() && shutdown_signal != -1) {
> +    if (!qtest_driver() && shutdown_signal) {
>          if (shutdown_pid == 0) {
>              /* This happens for eg ^C at the terminal, so it's worth
>               * avoiding printing an odd message in that case.
> @@ -1643,7 +1643,7 @@ static void qemu_kill_report(void)
>                           shutdown_cmd ? shutdown_cmd : "<unknown process>");
>              g_free(shutdown_cmd);
>          }
> -        shutdown_signal = -1;
> +        shutdown_signal = 0;
>      }
>  }
>
> --
> 2.9.3
>
>