src/common/xsignal.c

/*****************************************************************************\
 * src/common/xsignal.c - POSIX signal functions
 *****************************************************************************
 *  Copyright (C) 2002 The Regents of the University of California.
 *  Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
 *  Written by Mark Grondona <mgrondona@llnl.gov>.
 *  UCRL-CODE-226842.
 *  
 *  This file is part of SLURM, a resource management program.
 *  For details, see <http://www.llnl.gov/linux/slurm/>.
 *  
 *  SLURM is free software; you can redistribute it and/or modify it under
 *  the terms of the GNU General Public License as published by the Free
 *  Software Foundation; either version 2 of the License, or (at your option)
 *  any later version.
 *
 *  In addition, as a special exception, the copyright holders give permission 
 *  to link the code of portions of this program with the OpenSSL library under 
 *  certain conditions as described in each individual source file, and 
 *  distribute linked combinations including the two. You must obey the GNU 
 *  General Public License in all respects for all of the code used other than 
 *  OpenSSL. If you modify file(s) with this exception, you may extend this 
 *  exception to your version of the file(s), but you are not obligated to do 
 *  so. If you do not wish to do so, delete this exception statement from your
 *  version.  If you delete this exception statement from all source files in 
 *  the program, then also delete it here.
 *  
 *  SLURM 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 General Public License for more
 *  details.
 *  
 *  You should have received a copy of the GNU General Public License along
 *  with SLURM; if not, write to the Free Software Foundation, Inc.,
 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA.
\*****************************************************************************/

#if HAVE_CONFIG_H
#  include "config.h"
#endif

#include <errno.h>
#include <signal.h>

#include <slurm/slurm_errno.h>

#include "src/common/log.h"
#include "src/common/macros.h"
#include "src/common/xsignal.h"
#include "src/common/xassert.h"

/*
 * Define slurm-specific aliases for use by plugins, see slurm_xlator.h 
 * for details. 
 */
strong_alias(xsignal,		slurm_xsignal);
strong_alias(xsignal_save_mask,	slurm_xsignal_save_mask);
strong_alias(xsignal_set_mask,	slurm_xsignal_set_mask);
strong_alias(xsignal_block,	slurm_xsignal_block);
strong_alias(xsignal_unblock,	slurm_xsignal_unblock);
strong_alias(xsignal_sigset_create, slurm_xsignal_sigset_create);

SigFunc *
xsignal(int signo, SigFunc *f)
{
	struct sigaction sa, old_sa;

	sa.sa_handler = f;
	sigemptyset(&sa.sa_mask);
	sigaddset(&sa.sa_mask, signo);
	sa.sa_flags = 0;
	if (sigaction(signo, &sa, &old_sa) < 0)
		error("xsignal(%d) failed: %m", signo);
	return (old_sa.sa_handler);
}


/*
 *  Wrapper for pthread_sigmask.
 */
static int
_sigmask(int how, sigset_t *set, sigset_t *oset)
{
	int err;

	if ((err = pthread_sigmask(how, set, oset)))
		return error ("pthread_sigmask: %s", slurm_strerror(err));

	return SLURM_SUCCESS;
}


/*  
 *  Fill in the sigset_t with the list of signals in the
 *   the (zero-terminated) array of signals `sigarray.'
 */
int
xsignal_sigset_create(int sigarray[], sigset_t *setp)
{
	int i = 0, sig;

	if (sigemptyset(setp) < 0)
		error("sigemptyset: %m");

	while ((sig = sigarray[i++])) {
		if (sigaddset(setp, sig) < 0)
			return error ("sigaddset(%d): %m", sig);
	}

	return SLURM_SUCCESS;
}

int
xsignal_save_mask(sigset_t *set)
{
	sigemptyset(set);
	return _sigmask(SIG_SETMASK, NULL, set);
}

int
xsignal_set_mask(sigset_t *set)
{
	return _sigmask(SIG_SETMASK, set, NULL);
}

int
xsignal_block(int sigarray[])
{
	sigset_t set;

	xassert(sigarray != NULL);

	if (xsignal_sigset_create(sigarray, &set) < 0)
		return SLURM_ERROR;

	return _sigmask(SIG_BLOCK, &set, NULL);
}

int
xsignal_unblock(int sigarray[])
{
	sigset_t set;

	xassert(sigarray != NULL);

	if (xsignal_sigset_create(sigarray, &set) < 0)
		return SLURM_ERROR;

	return _sigmask(SIG_UNBLOCK, &set, NULL);
}