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
107 lines
3.7 KiB
C
107 lines
3.7 KiB
C
/****************************************************************************
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* sched/signal/sig_pause.c
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*
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* Copyright (C) 2012, 2016 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 <unistd.h>
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#include <signal.h>
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#include <errno.h>
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#include <nuttx/signal.h>
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#include <nuttx/cancelpt.h>
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/****************************************************************************
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* Public Functions
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****************************************************************************/
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/****************************************************************************
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* Name: pause
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*
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* Description:
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* The pause() function will suspend the calling thread until delivery of a
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* non-blocked signal.
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*
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* Input Parameters:
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* None
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*
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* Returned Value:
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* Since pause() suspends thread execution indefinitely unless interrupted
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* a signal, there is no successful completion return value. A value of -1
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* will always be returned and errno set to indicate the error (EINTR).
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*
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* POSIX compatibility:
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* In the POSIX description of this function is the pause() function will
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* suspend the calling thread until delivery of a signal whose action is
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* either to execute a signal-catching function or to terminate the
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* process. This implementation only waits for any non-blocked signal
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* to be received.
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*
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****************************************************************************/
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int pause(void)
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{
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sigset_t set;
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int ret;
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/* pause() is a cancellation point */
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enter_cancellation_point();
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/* Set up for the sleep. Using the empty set means that we are not
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* waiting for any particular signal. However, any unmasked signal
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* can still awaken sigtimedwait().
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*/
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sigemptyset(&set);
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/* sigtwaitinfo() cannot succeed. It should always return error EINTR
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* meaning that some unblocked signal was caught.
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*/
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ret = nxsig_waitinfo(&set, NULL);
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if (ret < 0)
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{
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set_errno(-ret);
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ret = ERROR;
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}
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leave_cancellation_point();
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return ret;
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}
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