On Thu, 2011-08-04 at 17:30 -0500, Bill Kendall wrote:
> Convert from using the System V signal API to the POSIX API. For
> xfsdump, this mostly means replacing sigrelse/sighold with
> sigprocmask, sigset with sigaction and sigpause with sigsuspend.
>
> Note that sigprocmask calls will be replaced with pthread_sigmask
> when pthread support is added to xfsdump.
>
> childmain() and cldmgr_entry() are thread entry points. By the time
> they are spawned the main thread will have already set its signal
> mask, so no need to setup signals in the thread as the mask is
> inherited.
>
> ring_slave_entry() is a thread entry point but is spawned before the
> main thread has its signal mask setup. Setup the thread's mask to
> block the same signals that the main thread will block. The main
> thread should be reworked to set its mask earlier, but that will
> require a fair amount of refactoring that is beyond the scope of
> this patch.
>
> Also simplify code to generate a core file to just use abort()
> rather than sending SIGQUIT and then waiting for it to arrive.
This all looks quite good to me. I have one request
and one question below.
Reviewed-by: Alex Elder <aelder@xxxxxxx>
> Signed-off-by: Bill Kendall <wkendall@xxxxxxx>
> diff --git a/common/main.c b/common/main.c
> index 825c894..d3b6662 100644
> --- a/common/main.c
> +++ b/common/main.c
> @@ -545,13 +545,20 @@ main( int argc, char *argv[] )
> * be released at pre-emption points and upon pausing in the main
> * loop.
> */
> +
> + struct sigaction sa;
Define this at the top of the block please.
Is there any requirement that the fields
other than sa_flags and sa_handler should
be zeroed before use?
> + sigfillset(&sa.sa_mask);
> + sa.sa_flags = 0;
>
> /* always ignore SIGPIPE, instead handle EPIPE as part
> * of normal sys call error handling
> */
> - sigset( SIGPIPE, SIG_IGN );
> + sa.sa_handler = SIG_IGN;
> + sigaction( SIGPIPE, &sa, NULL );
Are you guaranteed that the contents of "sa"
have not been modified by this call? I'm just
asking because you reuse it below and I just
don't know whether the standard says something
about it.
> if ( ! miniroot && ! pipeline ) {
> + sigset_t blocked_set;
> +
> stop_in_progress = BOOL_FALSE;
> coredump_requested = BOOL_FALSE;
> sighup_received = BOOL_FALSE;
> @@ -560,17 +567,23 @@ main( int argc, char *argv[] )
> sigquit_received = BOOL_FALSE;
> sigstray_received = BOOL_FALSE;
> prbcld_cnt = 0;
> - sigset( SIGINT, sighandler );
> - sighold( SIGINT );
> - sigset( SIGHUP, sighandler );
> - sighold( SIGHUP );
> - sigset( SIGTERM, sighandler );
> - sighold( SIGTERM );
> - sigset( SIGQUIT, sighandler );
> - sighold( SIGQUIT );
> +
> alarm( 0 );
> - sigset( SIGALRM, sighandler );
> - sighold( SIGALRM );
> +
> + sigemptyset( &blocked_set );
> + sigaddset( &blocked_set, SIGINT );
> + sigaddset( &blocked_set, SIGHUP );
> + sigaddset( &blocked_set, SIGTERM );
> + sigaddset( &blocked_set, SIGQUIT );
> + sigaddset( &blocked_set, SIGALRM );
> + sigprocmask( SIG_SETMASK, &blocked_set, NULL );
> +
> + sa.sa_handler = sighandler;
> + sigaction( SIGINT, &sa, NULL );
> + sigaction( SIGHUP, &sa, NULL );
> + sigaction( SIGTERM, &sa, NULL );
> + sigaction( SIGQUIT, &sa, NULL );
> + sigaction( SIGALRM, &sa, NULL );
> }
>
> /* do content initialization.
. . .
|