incubator-nuttx/sched/signal/sig_procmask.c

213 lines
6.9 KiB
C

/****************************************************************************
* sched/signal/sig_procmask.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <unistd.h>
#include <signal.h>
#include <time.h>
#include <sched.h>
#include <assert.h>
#include <errno.h>
#include <debug.h>
#include <nuttx/irq.h>
#include <nuttx/arch.h>
#include <nuttx/wdog.h>
#include <nuttx/kmalloc.h>
#include <nuttx/signal.h>
#include "sched/sched.h"
#include "signal/signal.h"
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxsig_procmask
*
* Description:
* This function allows the calling process to examine and/or change its
* signal mask. If the 'set' is not NULL, then it points to a set of
* signals to be used to change the currently blocked set. The value of
* 'how' indicates the manner in which the set is changed.
*
* If there any pending unblocked signals after the call to
* nxsig_procmask(), those signals will be delivered before
* nxsig_procmask() returns.
*
* If nxsig_procmask() fails, the signal mask of the process is not changed
* by this function call.
*
* This is an internal OS interface. It is functionally equivalent to
* sigprocmask() except that it does not modify the errno value.
*
* Input Parameters:
* how - How the signal mask will be changed:
* SIG_BLOCK - The resulting set is the union of the current set
* and the signal set pointed to by 'set'.
* SIG_UNBLOCK - The resulting set is the intersection of the current
* set and the complement of the signal set pointed to
* by 'set'.
* SIG_SETMASK - The resulting set is the signal set pointed to by
* 'set'.
* set - Location of the new signal mask
* oset - Location to store the old signal mask
*
* Returned Value:
* This is an internal OS interface and should not be used by applications.
* It follows the NuttX internal error return policy: Zero (OK) is
* returned on success. A negated errno value is returned on failure.
*
* EINVAL - The 'how' argument is invalid.
*
****************************************************************************/
int nxsig_procmask(int how, FAR const sigset_t *set, FAR sigset_t *oset)
{
FAR struct tcb_s *rtcb = this_task();
irqstate_t flags;
int ret = OK;
/* Return the old signal mask if requested */
if (oset != NULL)
{
*oset = rtcb->sigprocmask;
}
/* Modify the current signal mask if so requested */
if (set != NULL)
{
/* Some of these operations are non-atomic. We need to protect
* ourselves from attempts to process signals from interrupts
*/
flags = enter_critical_section();
/* Okay, determine what we are supposed to do */
switch (how)
{
/* The resulting set is the union of the current set and the
* signal set pointed to by set.
*/
case SIG_BLOCK:
sigorset(&rtcb->sigprocmask, &rtcb->sigprocmask, set);
break;
/* The resulting set is the intersection of the current set and
* the complement of the signal set pointed to by set.
*/
case SIG_UNBLOCK:
nxsig_nandset(&rtcb->sigprocmask, &rtcb->sigprocmask, set);
break;
/* The resulting set is the signal set pointed to by set. */
case SIG_SETMASK:
rtcb->sigprocmask = *set;
break;
default:
ret = -EINVAL;
break;
}
leave_critical_section(flags);
/* Now, process any pending signals that were just unmasked */
nxsig_unmask_pendingsignal();
}
return ret;
}
/****************************************************************************
* Name: sigprocmask
*
* Description:
* This function allows the calling process to examine and/or change its
* signal mask. If the 'set' is not NULL, then it points to a set of
* signals to be used to change the currently blocked set. The value of
* 'how' indicates the manner in which the set is changed.
*
* If there any pending unblocked signals after the call to sigprocmask(),
* those signals will be delivered before sigprocmask() returns.
*
* If sigprocmask() fails, the signal mask of the process is not changed
* by this function call.
*
* Input Parameters:
* how - How the signal mask will be changed:
* SIG_BLOCK - The resulting set is the union of the current set
* and the signal set pointed to by 'set'.
* SIG_UNBLOCK - The resulting set is the intersection of the current
* set and the complement of the signal set pointed to
* by 'set'.
* SIG_SETMASK - The resulting set is the signal set pointed to by
* 'set'.
* set - Location of the new signal mask
* oset - Location to store the old signal mask
*
* Returned Value:
* This function will return 0 (OK) on success or -1 (ERROR) if how is
* invalid. In the latter case, the errno variable will be set to EINVAL.
*
****************************************************************************/
int sigprocmask(int how, FAR const sigset_t *set, FAR sigset_t *oset)
{
sigset_t nset;
int ret;
/* SIGKILL and SIGSTOP should not be added to signal mask */
if (set != NULL)
{
nset = *set;
nxsig_delset(&nset, SIGKILL);
nxsig_delset(&nset, SIGSTOP);
set = &nset;
}
/* Let nxsig_procmask do all of the work */
ret = nxsig_procmask(how, set, oset);
if (ret < 0)
{
set_errno(-ret);
ret = ERROR;
}
return ret;
}