glibc/sysdeps/mach/hurd/sigaction.c
1995-02-18 01:27:10 +00:00

85 lines
2.4 KiB
C

/* Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <ansidecl.h>
#include <errno.h>
#include <signal.h>
#include <hurd.h>
#include <hurd/signal.h>
/* If ACT is not NULL, change the action for SIG to *ACT.
If OACT is not NULL, put the old action for SIG in *OACT. */
int
DEFUN(__sigaction, (sig, act, oact),
int sig AND CONST struct sigaction *act AND struct sigaction *oact)
{
struct hurd_sigstate *ss;
struct sigaction a, old;
sigset_t pending;
if (sig <= 0 || sig >= NSIG ||
(act != NULL && act->sa_handler != SIG_DFL &&
((__sigmask (sig) & _SIG_CANT_MASK) ||
act->sa_handler == SIG_ERR)))
{
errno = EINVAL;
return -1;
}
/* Copy so we fault before taking locks. */
if (act != NULL)
a = *act;
ss = _hurd_self_sigstate ();
__spin_lock (&ss->lock);
old = ss->actions[sig];
if (act != NULL)
ss->actions[sig] = a;
if (act != NULL && sig == SIGCHLD)
{
ss->critical_section = 1;
__spin_unlock (&ss->lock);
/* Inform the proc server whether or not it should send us SIGCHLD for
stopped children. We do this in a critical section so that no
SIGCHLD can arrive in the middle and be of indeterminate status. */
__USEPORT (PROC,
__proc_mod_stopchild (port, !(a.sa_flags & SA_NOCLDSTOP)));
__spin_lock (&ss->lock);
ss->critical_section = 0;
pending = ss->pending & ~ss->blocked;
}
else
pending = 0;
__spin_unlock (&ss->lock);
if (pending)
__msg_sig_post (_hurd_msgport, 0, __mach_task_self ());
if (oact != NULL)
*oact = old;
return 0;
}
weak_alias (__sigaction, sigaction)