X-Git-Url: http://v3vee.org/palacios/gitweb/gitweb.cgi?p=palacios.git;a=blobdiff_plain;f=geekos%2Fsrc%2Fnet%2Ftimer.c;fp=geekos%2Fsrc%2Fnet%2Ftimer.c;h=b615f0acf0e97ca71cc0c6a2e2e21d6473f18cff;hp=0000000000000000000000000000000000000000;hb=ddc16b0737cf58f7aa90a69c6652cdf4090aec51;hpb=626595465a2c6987606a6bc697df65130ad8c2d3 diff --git a/geekos/src/net/timer.c b/geekos/src/net/timer.c new file mode 100644 index 0000000..b615f0a --- /dev/null +++ b/geekos/src/net/timer.c @@ -0,0 +1,127 @@ +/** + * \addtogroup timer + * @{ + */ + +/** + * \file + * Timer library implementation. + * \author + * Adam Dunkels + */ + +/* + * 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 uIP TCP/IP stack + * + * Author: Adam Dunkels + * + * $Id: timer.c,v 1.1 2008/08/06 23:21:19 andrewlxia Exp $ + */ + +#include +#include + +/*---------------------------------------------------------------------------*/ +/** + * Set a timer. + * + * This function is used to set a timer for a time sometime in the + * future. The function timer_expired() will evaluate to true after + * the timer has expired. + * + * \param t A pointer to the timer + * \param interval The interval before the timer expires. + * + */ +void +timer_set(struct timer *t, clock_time_t 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_rester() 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) +{ + return (clock_time_t)(clock_time() - t->start) >= (clock_time_t)t->interval; +} +/*---------------------------------------------------------------------------*/ + +/** @} */