incubator-nuttx/sched/signal/sig_usleep.c

102 lines
3.8 KiB
C

/****************************************************************************
* sched/sig_usleep.c
*
* Copyright (C) 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 <sys/types.h>
#include <unistd.h>
#include <signal.h>
#include <assert.h>
#include <errno.h>
#include <nuttx/signal.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxsig_usleep
*
* Description:
* The nxsig_usleep() function will cause the calling thread to be
* suspended from execution until either the number of real-time
* microseconds specified by the argument 'usec' has elapsed or a signal
* is delivered to the calling thread. The suspension time may be longer
* than requested due to the scheduling of other activity by the system.
*
* This is an internal OS interface. It is functionally equivalent to
* the standard nxsig_usleep() application interface except that:
*
* - It is not a cancellation point, and
* - It does not modify the errno value.
*
* See the description of usleep() for additional information that is not
* duplicated here.
*
* Input Parameters:
* usec - the number of microseconds to wait.
*
* Returned Value:
* This is an internal OS interface and should not be used by applications.
* It follows the NuttX internal error return policy: Zero (OK) is
* returned on success. A negated errno value is returned on failure.
*
****************************************************************************/
int nxsig_usleep(useconds_t usec)
{
struct timespec rqtp;
time_t sec;
int ret = 0;
if (usec)
{
/* Let nxsig_nanosleep() do all of the work. */
sec = usec / 1000000;
rqtp.tv_sec = sec;
rqtp.tv_nsec = (usec - (sec * 1000000)) * 1000;
ret = nxsig_nanosleep(&rqtp, NULL);
}
return ret;
}