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/****************************************************************************
* system/zmodem/zm_watchdog.c
*
* Copyright (C) 2013 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 <stdio.h>
#include <signal.h>
#include <time.h>
#include <errno.h>
#include "zm.h"
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: zm_expiry
*
* Description:
* SIGALRM signal handler. Simply posts the timeout event.
*
****************************************************************************/
static void zm_expiry(int signo, FAR siginfo_t *info, FAR void *context)
{
FAR struct zm_state_s *pzm = (FAR struct zm_state_s *)info->si_value.sival_ptr;
/* Just set the timeout flag. If the Zmodem logic was truly waiting, then
* the signal should wake it up and it should then process the timeout
* condition.
*
* REVISIT: This is a read-modify-write operation and has the potential
* for atomicity issue. We might need to use a dedicated boolean value
* to indicate to timeout!
*/
pzm->flags |= ZM_FLAG_TIMEOUT;
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: zm_timerinit
*
* Description:
* Create the POSIX timer used to manage timeouts and attach the SIGALRM
* signal handler to catch the timeout events.
*
****************************************************************************/
int zm_timerinit(FAR struct zm_state_s *pzm)
{
struct sigevent toevent;
struct sigaction act;
int ret;
/* Create a POSIX timer to handle timeouts */
toevent.sigev_notify = SIGEV_SIGNAL;
toevent.sigev_signo = SIGALRM;
toevent.sigev_value.sival_ptr = pzm;
ret = timer_create(CLOCK_REALTIME, &toevent, &pzm->timer);
if (ret < 0)
{
int errorcode = errno;
zmdbg("ERROR: Failed to create a timer: %d\n", errorcode);
return -errorcode;
}
/* Attach a signal handler to catch the timeout */
act.sa_sigaction = zm_expiry;
act.sa_flags = SA_SIGINFO;
sigemptyset(&act.sa_mask);
ret = sigaction(SIGALRM, &act, NULL);
if (ret < 0)
{
int errorcode = errno;
zmdbg("ERROR: Failed to attach a signal handler: %d\n", errorcode);
return -errorcode;
}
return OK;
}
/****************************************************************************
* Name: zm_timerstart
*
* Description:
* Start, restart, or stop the timer.
*
****************************************************************************/
int zm_timerstart(FAR struct zm_state_s *pzm, unsigned int sec)
{
struct itimerspec todelay;
int ret;
/* Start, restart, or stop the timer */
todelay.it_interval.tv_sec = 0; /* Nonrepeating */
todelay.it_interval.tv_nsec = 0;
todelay.it_value.tv_sec = sec;
todelay.it_value.tv_nsec = 0;
ret = timer_settime(pzm->timer, 0, &todelay, NULL);
if (ret < 0)
{
int errorcode = errno;
zmdbg("ERROR: Failed to set the timer: %d\n", errorcode);
return -errorcode;
}
return OK;
}
/****************************************************************************
* Name: zm_timerrelease
*
* Description:
* Destroy the timer and and detach the signal handler.
*
****************************************************************************/
int zm_timerrelease(FAR struct zm_state_s *pzm)
{
struct sigaction act;
int result;
int ret = OK;
/* Delete the POSIX timer */
result = timer_delete(pzm->timer);
if (result < 0)
{
int errorcode = errno;
zmdbg("ERROR: Failed to delete the timer: %d\n", errorcode);
ret = -errorcode;
}
/* Revert to the default signal behavior */
act.sa_handler = SIG_DFL;
act.sa_flags = 0;
sigemptyset(&act.sa_mask);
result = sigaction(SIGALRM, &act, NULL);
if (result < 0)
{
int errorcode = errno;
zmdbg("ERROR: Failed to detach the signal handler: %d\n", errorcode);
ret = -errorcode;
}
return ret;
}
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