6a3c2aded6
* Simplify EINTR/ECANCEL error handling 1. Add semaphore uninterruptible wait function 2 .Replace semaphore wait loop with a single uninterruptible wait 3. Replace all sem_xxx to nxsem_xxx * Unify the void cast usage 1. Remove void cast for function because many place ignore the returned value witout cast 2. Replace void cast for variable with UNUSED macro
124 lines
4.4 KiB
C
124 lines
4.4 KiB
C
/****************************************************************************
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* libs/libc/signal/sig_signal.c
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*
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* Copyright (C) 2015-2017 Gregory Nutt. All rights reserved.
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* Author: Gregory Nutt <gnutt@nuttx.org>
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in
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* the documentation and/or other materials provided with the
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* distribution.
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* 3. Neither the name NuttX nor the names of its contributors may be
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* used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
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* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
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* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*
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****************************************************************************/
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/****************************************************************************
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* Included Files
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****************************************************************************/
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#include <nuttx/config.h>
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#include <signal.h>
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#include <assert.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: signal
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*
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* Description:
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* The signal() function will modify signal dispositions. The 'signo'
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* argument specifies the signal. The 'func' argument specifies the
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* signal's disposition, which may be SIG_DFL, SIG_IGN, or the address
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* of a signal handler. If 'func' is the address of a signal handler, the
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* system will add 'signo' to the calling process' signal mask before
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* executing the signal handler; when the signal handler returns, the
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* system will restore the calling process' signal mask to its state prior
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* to the delivery of the signal.
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*
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* Input Parameters:
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* signo - Identifies the signal to operate on
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* func - The new disposition of the signal
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*
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* Returned Value:
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* Upon successful completion, signal() will return the previous
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* disposition of the signal handling. Otherwise, SIG_ERR will be returned
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* and errno set to indicate the nature of the error.
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*
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****************************************************************************/
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_sa_handler_t signal(int signo, _sa_handler_t func)
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{
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struct sigaction act;
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struct sigaction oact;
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int ret;
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DEBUGASSERT(GOOD_SIGNO(signo) && func != SIG_ERR && func != SIG_HOLD);
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/* Initialize the sigaction structure */
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act.sa_handler = func;
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act.sa_flags = 0;
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sigemptyset(&act.sa_mask);
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/* Check for SIG_IGN and SIG_DFL (and someday SIG_HOLD)
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*
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* REVISIT: Currently SIG_IGN, SIG_DFL, and SIG_HOLD have the same value
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* and cannot be distinguished.
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*/
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if (func != SIG_DFL /* && func != SIG_IGN */)
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{
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/* Add the signal to the set of signals to be ignored when the signal
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* handler executes.
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*/
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ret = sigaddset(&act.sa_mask, signo);
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if (ret < 0)
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{
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/* Would happen if signo were invalid */
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return (_sa_handler_t)SIG_ERR;
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}
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}
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/* Set the signal disposition */
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ret = sigaction(signo, &act, &oact);
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/* Upon successful completion, signal() will the signal's previous
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* disposition. Otherwise, SIG_ERR will be returned and errno set to
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* indicate the error.
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*/
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if (ret == OK)
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{
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return oact.sa_handler;
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}
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return (_sa_handler_t)SIG_ERR;
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}
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