Diff: platform/src/gp_timer.c

Revision:

0:a948f5f3904c

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/platform/src/gp_timer.c	Fri Dec 19 18:56:07 2014 +0000
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2004, Swedish Institute of Computer Science.
+ * 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.
+ *
+ * This file is part of the Contiki operating system.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+#include "clock.h"
+#include "gp_timer.h"
+
+/*---------------------------------------------------------------------------*/
+/**
+ * Set a timer.
+ *
+ * This function sets a timer for a time sometime in the
+ * future. The function timer_expired() will evaluate to true after
+ * the timer has expired.
+ *
+ * @param[in] t         A pointer to the timer
+ * @param[in] interval  The interval before the timer expires.
+ *
+ */
+void
+Timer_Set(struct timer *t, tClockTime interval)
+{
+  t->interval = interval;
+  t->start = Clock_Time();
+}
+/*---------------------------------------------------------------------------*/
+/**
+ * Reset the timer with the same interval.
+ *
+ * This function resets the timer with the same interval that was
+ * given to the timer_set() function. The start point of the interval
+ * is the exact time that the timer last expired. Therefore, this
+ * function will cause the timer to be stable over time, unlike the
+ * timer_restart() function.
+ *
+ * \param t A pointer to the timer.
+ *
+ * \sa timer_restart()
+ */
+void
+Timer_Reset(struct timer *t)
+{
+  t->start += t->interval;
+}
+/*---------------------------------------------------------------------------*/
+/**
+ * Restart the timer from the current point in time
+ *
+ * This function restarts a timer with the same interval that was
+ * given to the timer_set() function. The timer will start at the
+ * current time.
+ *
+ * \note A periodic timer will drift if this function is used to reset
+ * it. For preioric timers, use the timer_reset() function instead.
+ *
+ * \param t A pointer to the timer.
+ *
+ * \sa timer_reset()
+ */
+void
+Timer_Restart(struct timer *t)
+{
+  t->start = Clock_Time();
+}
+/*---------------------------------------------------------------------------*/
+/**
+ * Check if a timer has expired.
+ *
+ * This function tests if a timer has expired and returns true or
+ * false depending on its status.
+ *
+ * \param t A pointer to the timer
+ *
+ * \return Non-zero if the timer has expired, zero otherwise.
+ *
+ */
+int
+Timer_Expired(struct timer *t)
+{
+  /* Note: Can not return diff >= t->interval so we add 1 to diff and return
+     t->interval < diff - required to avoid an internal error in mspgcc. */
+  tClockTime diff = (Clock_Time() - t->start) + 1;
+  return t->interval < diff;
+
+}
+/*---------------------------------------------------------------------------*/
+/**
+ * The time until the timer expires
+ *
+ * This function returns the time until the timer expires.
+ *
+ * \param t A pointer to the timer
+ *
+ * \return The time until the timer expires
+ *
+ */
+tClockTime
+Timer_Remaining(struct timer *t)
+{
+  return t->start + t->interval - Clock_Time();
+}
+/*---------------------------------------------------------------------------*/
+
+/** @} */
+
+
+
+