[pacman-dev] [PATCH] Revamp pacman signal handler

[dave reisner]

On Sep 26, 2011 4:29 PM, "Dan McGee" <dan at archlinux.org> wrote:
>
> * All errors now go to stdout

I think you meant stderr here. Looks good otherwise. Do we want to handle a
SIGQUIT which is easily accessible from a shell (ctrl-/)?

D

, so do the same here and simplify the
>  writing of the error message.
> * Add SIGHUP to the handled signal list, and don't repeat code.
> * Attempt to release the transaction (e.g. remove the lock file)
>  for all of HUP, INT, and TERM. Signals HUP and INT respects
>  transaction state, TERM will immediately terminate the process.
>
> Signed-off-by: Dan McGee <dan at archlinux.org>
> ---
>  src/pacman/pacman.c |   46 +++++++++++++++++++++++-----------------------
>  1 files changed, 23 insertions(+), 23 deletions(-)
>
> diff --git a/src/pacman/pacman.c b/src/pacman/pacman.c
> index 061d593..40aa444 100644
> --- a/src/pacman/pacman.c
> +++ b/src/pacman/pacman.c
> @@ -299,26 +299,29 @@ static void handler(int signum)
>  {
>        int out = fileno(stdout);
>        int err = fileno(stderr);
> +       const char *msg;
>        if(signum == SIGSEGV) {
> -               const char *msg1 = "error: segmentation fault\n";
> -               const char *msg2 = "Internal pacman error: Segmentation
fault.\n"
> +               msg = "\nerror: segmentation fault\n"
>                        "Please submit a full bug report with --debug if
appropriate.\n";
> -               /* write a error message to out, the rest to err */
> -               xwrite(out, msg1, strlen(msg1));
> -               xwrite(err, msg2, strlen(msg2));
> +               xwrite(err, msg, strlen(msg));
>                exit(signum);
> -       } else if(signum == SIGINT) {
> -               const char *msg = "\nInterrupt signal received\n";
> +       } else if(signum == SIGINT || signum == SIGHUP) {
> +               if(signum == SIGINT) {
> +                       msg = "\nInterrupt signal received\n";
> +               } else {
> +                       msg = "\nHangup signal received\n";
> +               }
>                xwrite(err, msg, strlen(msg));
>                if(alpm_trans_interrupt(config->handle) == 0) {
>                        /* a transaction is being interrupted, don't exit
pacman yet. */
>                        return;
>                }
> -               /* no commiting transaction, we can release it now and
then exit pacman */
> -               alpm_trans_release(config->handle);
> -               /* output a newline to be sure we clear any line we may be
on */
> -               xwrite(out, "\n", 1);
>        }
> +       /* SIGINT: no commiting transaction, release it now and then exit
pacman
> +        * SIGHUP, SIGTERM: release no matter what */
> +       alpm_trans_release(config->handle);
> +       /* output a newline to be sure we clear any line we may be on */
> +       xwrite(out, "\n", 1);
>        cleanup(128 + signum);
>  }
>
> @@ -757,8 +760,9 @@ static void cl_to_log(int argc, char* argv[])
>  */
>  int main(int argc, char *argv[])
>  {
> -       int ret = 0;
> +       int i, ret = 0;
>        struct sigaction new_action, old_action;
> +       const int signals[] = { SIGHUP, SIGINT, SIGTERM, SIGSEGV };
>  #if defined(HAVE_GETEUID) && !defined(CYGWIN)
>        /* geteuid undefined in CYGWIN */
>        uid_t myuid = geteuid();
> @@ -775,17 +779,13 @@ int main(int argc, char *argv[])
>        sigemptyset(&new_action.sa_mask);
>        new_action.sa_flags = 0;
>
> -       sigaction(SIGINT, NULL, &old_action);
> -       if(old_action.sa_handler != SIG_IGN) {
> -               sigaction(SIGINT, &new_action, NULL);
> -       }
> -       sigaction(SIGTERM, NULL, &old_action);
> -       if(old_action.sa_handler != SIG_IGN) {
> -               sigaction(SIGTERM, &new_action, NULL);
> -       }
> -       sigaction(SIGSEGV, NULL, &old_action);
> -       if(old_action.sa_handler != SIG_IGN) {
> -               sigaction(SIGSEGV, &new_action, NULL);
> +       /* assign our handler to any signals we care about */
> +       for(i = 0; i < sizeof(signals) / sizeof(signals[0]); i++) {
> +               int signal = signals[i];
> +               sigaction(signal, NULL, &old_action);
> +               if(old_action.sa_handler != SIG_IGN) {
> +                       sigaction(signal, &new_action, NULL);
> +               }
>        }
>
>        /* i18n init */
> --
> 1.7.6.3
>
>