glibc/hurd/preempt-sig.c

69 lines
2.1 KiB
C

/* Copyright (C) 1994, 1995, 1996 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., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <hurd/sigpreempt.h>
#include <hurd/signal.h>
#include <assert.h>
void
hurd_preempt_signals (struct hurd_signal_preemptor *preemptor)
{
__mutex_lock (&_hurd_siglock);
preemptor->next = _hurdsig_preemptors;
_hurdsig_preemptors = preemptor;
_hurdsig_preempted_set |= preemptor->signals;
__mutex_unlock (&_hurd_siglock);
}
void
hurd_unpreempt_signals (struct hurd_signal_preemptor *preemptor)
{
struct hurd_signal_preemptor **p;
sigset_t preempted = 0;
__mutex_lock (&_hurd_siglock);
p = &_hurdsig_preemptors;
while (*p)
if (*p == preemptor)
{
/* Found it; take it off the chain. */
*p = (*p)->next;
if ((preemptor->signals & preempted) != preemptor->signals)
{
/* This might have been the only preemptor for some
of those signals, so we must collect the full mask
from the others. */
struct hurd_signal_preemptor *pp;
for (pp = *p; pp; pp = pp->next)
preempted |= pp->signals;
_hurdsig_preempted_set = preempted;
}
__mutex_unlock (&_hurd_siglock);
return;
}
else
{
preempted |= (*p)->signals;
p = &(*p)->next;
}
__mutex_unlock (&_hurd_siglock); /* Avoid deadlock during death rattle. */
assert (! "removing absent preemptor");
}