nuttx/libs/libc/signal/signal.c
Gregory Nutt cf99fb40c9 This commit moves all of the libraries under a common directory called libs/. This most certainly break libcxx and uClibc++ for now.
Squashed commit of the following:

    libs/libxx:  Fix some confusing in naming.  If the directory is called libxx, then the library must be libxx.a (unless perhaps LIBCXX is selected).
    libs/:  Fix paths in moved library directories.
    libs:  Brute force move of libc, libnx, and libxx to libs.  Cannot yet build it in that configuration.
2018-05-29 13:21:26 -06:00

124 lines
4.4 KiB
C

/****************************************************************************
* libs/libc/signal/signal.c
*
* Copyright (C) 2015-2017 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* 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;
(void)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;
}