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