glibc/sysdeps/posix/sigvec.c
1996-10-02 01:40:17 +00:00

166 lines
3.8 KiB
C

/* Copyright (C) 1991, 92, 94, 95, 96 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 <signal.h>
#include <errno.h>
#include <stddef.h>
/* We use a wrapper handler to support SV_RESETHAND. */
static __sighandler_t wrapped_handlers[NSIG];
static sigset_t wrapped_masks[NSIG];
static void wrapper_handler __P ((int sig));
static inline int convert_mask __P ((sigset_t *set, const int mask));
static void
wrapper_handler (sig)
int sig;
{
int save;
struct sigaction act;
act.sa_handler = SIG_DFL;
act.sa_mask = wrapped_masks[sig];
act.sa_flags = 0;
save = errno;
(void) __sigaction (sig, &act, (struct sigaction *) NULL);
__set_errno (save);
(*wrapped_handlers[sig]) (sig);
}
static inline int
convert_mask (set, mask)
sigset_t *set;
const int mask;
{
register int sig;
if (sizeof (*set) == sizeof (mask))
{
*(int *) set = mask;
return 0;
}
if (__sigemptyset (set) < 0)
return -1;
for (sig = 1; sig < NSIG; ++sig)
if (mask & sigmask (sig))
if (__sigaddset (set, sig) < 0)
return -1;
return 0;
}
/* If VEC is non-NULL, set the handler for SIG to the `sv_handler' member
of VEC. The signals in `sv_mask' will be blocked while the handler runs.
If the SV_RESETHAND bit is set in `sv_flags', the handler for SIG will be
reset to SIG_DFL before `sv_handler' is entered. If OVEC is non-NULL,
it is filled in with the old information for SIG. */
int
__sigvec (sig, vec, ovec)
int sig;
const struct sigvec *vec;
struct sigvec *ovec;
{
struct sigaction old;
if (vec == NULL || !(vec->sv_flags & SV_RESETHAND))
{
struct sigaction new, *n;
if (vec == NULL)
n = NULL;
else
{
n = &new;
n->sa_handler = vec->sv_handler;
if (convert_mask (&n->sa_mask, vec->sv_mask) < 0)
return -1;
n->sa_flags = 0;
if (vec->sv_flags & SV_ONSTACK)
{
#ifdef SA_ONSTACK
n->sa_flags |= SA_ONSTACK;
#else
__set_errno (ENOSYS);
return -1;
#endif
}
#ifdef SA_RESTART
if (!(vec->sv_flags & SV_INTERRUPT))
n->sa_flags |= SA_RESTART;
#endif
}
if (__sigaction (sig, n, &old) < 0)
return -1;
}
else
{
struct sigaction wrapper;
wrapper.sa_handler = wrapper_handler;
wrapped_handlers[sig] = vec->sv_handler;
if (convert_mask (&wrapped_masks[sig], vec->sv_mask) < 0)
return -1;
if (__sigaction (sig, &wrapper, &old) < 0)
return -1;
}
if (ovec != NULL)
{
register int i;
int mask = 0;
if (sizeof (int) == sizeof (sigset_t))
mask = *(int *) &old.sa_mask;
else
for (i = 1; i < NSIG; ++i)
if (__sigismember(&old.sa_mask, i))
mask |= sigmask(i);
ovec->sv_mask = mask;
ovec->sv_flags = 0;
#ifdef SA_ONSTACK
if (old.sa_flags & SA_ONSTACK)
ovec->sv_flags |= SV_ONSTACK;
#endif
#ifdef SA_RESTART
if (!(old.sa_flags & SA_RESTART))
#endif
ovec->sv_flags |= SV_INTERRUPT;
if (old.sa_handler == wrapper_handler)
{
ovec->sv_flags |= SV_RESETHAND;
ovec->sv_handler = wrapped_handlers[sig];
}
else
ovec->sv_handler = old.sa_handler;
}
return 0;
}
weak_alias (__sigvec, sigvec)