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Diffstat (limited to 'apps/system/zmodem/zm_watchdog.c')
-rw-r--r-- | apps/system/zmodem/zm_watchdog.c | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/apps/system/zmodem/zm_watchdog.c b/apps/system/zmodem/zm_watchdog.c new file mode 100644 index 000000000..48b983acf --- /dev/null +++ b/apps/system/zmodem/zm_watchdog.c @@ -0,0 +1,197 @@ +/**************************************************************************** + * 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; +} |