nes-proj/os/net/app-layer/coap/coap-timer-default.c

/*
 * Copyright (c) 2016, SICS, Swedish ICT AB.
 * All rights reserved.
 *
 * 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 of the Institute 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 INSTITUTE 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 INSTITUTE 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.
 */

/**
 * \file
 *         CoAP timer driver implementation based on Contiki etimers
 * \author
 *         Niclas Finne <nfi@sics.se>
 *         Joakim Eriksson <joakime@sics.se>
 */

/**
 * \addtogroup coap-timer
 * @{
 *
 * \defgroup coap-timer-default CoAP timer for Contiki-NG
 * @{
 *
 * This is an implementation of CoAP timer for Contiki-NG.
 */

#include "coap-timer.h"
#include "sys/clock.h"
#include "sys/etimer.h"
#include "sys/process.h"

/* Log configuration */
#include "coap-log.h"
#define LOG_MODULE "coap-timer"
#define LOG_LEVEL  LOG_LEVEL_NONE

PROCESS(coap_timer_process, "coap timer process");

static uint64_t current_time;
static struct etimer timer;
/*---------------------------------------------------------------------------*/
static void
update_timer(void)
{
  uint64_t remaining;
  remaining = coap_timer_time_to_next_expiration();
  LOG_DBG("remaining %lu msec\n", (unsigned long)remaining);
  if(remaining == 0) {
    /* Run as soon as possible */
    process_poll(&coap_timer_process);
  } else {
    remaining *= CLOCK_SECOND;
    remaining /= 1000;
    if(remaining > CLOCK_SECOND * 60) {
      /* Make sure the CoAP timer clock is updated at least once per minute */
      remaining = CLOCK_SECOND * 60;
    } else if(remaining < 1) {
      /* Wait minimum one system clock tick */
      remaining = 1;
    }
    etimer_set(&timer, (clock_time_t)remaining);
  }
}
/*---------------------------------------------------------------------------*/
PROCESS_THREAD(coap_timer_process, ev, data)
{
  PROCESS_BEGIN();

  etimer_set(&timer, CLOCK_SECOND);
  while(1) {
    PROCESS_WAIT_EVENT_UNTIL(ev == PROCESS_EVENT_TIMER ||
                             ev == PROCESS_EVENT_POLL);

    if(coap_timer_run()) {
      /* Needs to run again */
      process_poll(&coap_timer_process);
    } else {
      update_timer();
    }
  }
  PROCESS_END();
}
/*---------------------------------------------------------------------------*/
static uint64_t
uptime(void)
{
  static clock_time_t last;
  clock_time_t now;
  uint64_t diff;

  now = clock_time();
  diff = (clock_time_t)(now - last);
  if(diff > 0) {
    current_time += (diff * 1000) / CLOCK_SECOND;
    last = now;
  }
  return current_time;
}
/*---------------------------------------------------------------------------*/
static void
init(void)
{
  process_start(&coap_timer_process, NULL);
}
/*---------------------------------------------------------------------------*/
static void
update(void)
{
  process_poll(&coap_timer_process);
}
/*---------------------------------------------------------------------------*/
const coap_timer_driver_t coap_timer_default_driver = {
  .init = init,
  .uptime = uptime,
  .update = update,
};
/*---------------------------------------------------------------------------*/
/** @} */
/** @} */