ldom_utils.c revision e6590bdc0d540003c7df26f1d3b66db7cae9be2c
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2010 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* ldom_utils.c
*
* Common functions within the library
*
*/
#include <stdio.h>
#include <signal.h>
#include <pthread.h>
/*
* ldom_find_thr_sig()
* Description:
* Find an unmasked signal which is used for terminating the thread
*
* If the libldom.so thread is started before all fmd modules are loaded,
* all signals are unmasked. Either SIGTERM or SIGUSR1 can be used to
* stop the thread.
* If the thread is started by a fmd module, fmd has masked all signals
* except the client.thrsig and a list of reserver/non-catchable signals.
* The fmd client.thrsig signal must be used to stop the thread. The default
* value of the client.thrsig is SIGUSR1.
*
* This fucntion first tries to check if the SIGTERM, SIGUSR1 or SIGUSR2
* signal is umasked. If so, select this signal.
* Otherwise, go through all the signals and find an umasked one.
*/
int
ldom_find_thr_sig(void)
{
int i;
sigset_t oset, rset;
int sig[] = {SIGTERM, SIGUSR1, SIGUSR2};
int sig_sz = sizeof (sig) / sizeof (int);
int rc = SIGTERM;
/* prefered set of signals that are likely used to terminate threads */
(void) sigemptyset(&oset);
(void) pthread_sigmask(SIG_SETMASK, NULL, &oset);
for (i = 0; i < sig_sz; i++) {
if (sigismember(&oset, sig[i]) == 0) {
return (sig[i]);
}
}
/* reserved set of signals that are not allowed to terminate thread */
(void) sigemptyset(&rset);
(void) sigaddset(&rset, SIGABRT);
(void) sigaddset(&rset, SIGKILL);
(void) sigaddset(&rset, SIGSTOP);
(void) sigaddset(&rset, SIGCANCEL);
/* Find signal that is not masked and not in the reserved list. */
for (i = 1; i < MAXSIG; i++) {
if (sigismember(&rset, i) == 1) {
continue;
}
if (sigismember(&oset, i) == 0) {
return (i);
}
}
return (rc);
}