nuttx/libs/libc/signal/sig_signal.c
Alin Jerpelea d6b50a1d3f libs: nxstyle fixes
nxstyle fixes to pass the CI checks

Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
2021-03-03 18:52:53 -08:00

109 lines
3.6 KiB
C

/****************************************************************************
* libs/libc/signal/sig_signal.c
*
* 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 <signal.h>
#include <assert.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: signal
*
* Description:
* The signal() function will modify signal dispositions. The 'signo'
* argument specifies the signal. The 'func' argument specifies the
* signal's disposition, which may be SIG_DFL, SIG_IGN, or the address
* of a signal handler. If 'func' is the address of a signal handler, the
* system will add 'signo' to the calling process' signal mask before
* executing the signal handler; when the signal handler returns, the
* system will restore the calling process' signal mask to its state prior
* to the delivery of the signal.
*
* Input Parameters:
* signo - Identifies the signal to operate on
* func - The new disposition of the signal
*
* Returned Value:
* Upon successful completion, signal() will return the previous
* disposition of the signal handling. Otherwise, SIG_ERR will be returned
* and errno set to indicate the nature of the error.
*
****************************************************************************/
_sa_handler_t signal(int signo, _sa_handler_t func)
{
struct sigaction act;
struct sigaction oact;
int ret;
DEBUGASSERT(GOOD_SIGNO(signo) && func != SIG_ERR && func != SIG_HOLD);
/* Initialize the sigaction structure */
act.sa_handler = func;
act.sa_flags = 0;
sigemptyset(&act.sa_mask);
/* Check for SIG_IGN and SIG_DFL (and someday SIG_HOLD)
*
* REVISIT: Currently SIG_IGN, SIG_DFL, and SIG_HOLD have the same value
* and cannot be distinguished.
*/
if (func != SIG_DFL /* && func != SIG_IGN */)
{
/* Add the signal to the set of signals to be ignored when the signal
* handler executes.
*/
ret = sigaddset(&act.sa_mask, signo);
if (ret < 0)
{
/* Would happen if signo were invalid */
return (_sa_handler_t)SIG_ERR;
}
}
/* Set the signal disposition */
ret = sigaction(signo, &act, &oact);
/* Upon successful completion, signal() will the signal's previous
* disposition. Otherwise, SIG_ERR will be returned and errno set to
* indicate the error.
*/
if (ret == OK)
{
return oact.sa_handler;
}
return (_sa_handler_t)SIG_ERR;
}