From ec8b4501c7b0bfb286db7789635168d1b84f9105 Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Sat, 20 Feb 2010 20:34:29 +0100 Subject: intial checkin of the libosmocore project --- src/timer.c | 185 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 185 insertions(+) create mode 100644 src/timer.c (limited to 'src/timer.c') diff --git a/src/timer.c b/src/timer.c new file mode 100644 index 00000000..37d7d166 --- /dev/null +++ b/src/timer.c @@ -0,0 +1,185 @@ +/* + * (C) 2008,2009 by Holger Hans Peter Freyther + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + * + */ + +#include +#include +#include + +static LLIST_HEAD(timer_list); +static struct timeval s_nearest_time; +static struct timeval s_select_time; + +#define MICRO_SECONDS 1000000LL + +#define TIME_SMALLER(left, right) \ + (left.tv_sec*MICRO_SECONDS+left.tv_usec) <= (right.tv_sec*MICRO_SECONDS+right.tv_usec) + +void bsc_add_timer(struct timer_list *timer) +{ + struct timer_list *list_timer; + + /* TODO: Optimize and remember the closest item... */ + timer->active = 1; + + /* this might be called from within update_timers */ + llist_for_each_entry(list_timer, &timer_list, entry) + if (timer == list_timer) + return; + + timer->in_list = 1; + llist_add(&timer->entry, &timer_list); +} + +void bsc_schedule_timer(struct timer_list *timer, int seconds, int microseconds) +{ + struct timeval current_time; + + gettimeofday(¤t_time, NULL); + unsigned long long currentTime = current_time.tv_sec * MICRO_SECONDS + current_time.tv_usec; + currentTime += seconds * MICRO_SECONDS + microseconds; + timer->timeout.tv_sec = currentTime / MICRO_SECONDS; + timer->timeout.tv_usec = currentTime % MICRO_SECONDS; + bsc_add_timer(timer); +} + +void bsc_del_timer(struct timer_list *timer) +{ + if (timer->in_list) { + timer->active = 0; + timer->in_list = 0; + llist_del(&timer->entry); + } +} + +int bsc_timer_pending(struct timer_list *timer) +{ + return timer->active; +} + +/* + * if we have a nearest time return the delta between the current + * time and the time of the nearest timer. + * If the nearest timer timed out return NULL and then we will + * dispatch everything after the select + */ +struct timeval *bsc_nearest_timer() +{ + struct timeval current_time; + + if (s_nearest_time.tv_sec == 0 && s_nearest_time.tv_usec == 0) + return NULL; + + if (gettimeofday(¤t_time, NULL) == -1) + return NULL; + + unsigned long long nearestTime = s_nearest_time.tv_sec * MICRO_SECONDS + s_nearest_time.tv_usec; + unsigned long long currentTime = current_time.tv_sec * MICRO_SECONDS + current_time.tv_usec; + + if (nearestTime < currentTime) { + s_select_time.tv_sec = 0; + s_select_time.tv_usec = 0; + } else { + s_select_time.tv_sec = (nearestTime - currentTime) / MICRO_SECONDS; + s_select_time.tv_usec = (nearestTime - currentTime) % MICRO_SECONDS; + } + + return &s_select_time; +} + +/* + * Find the nearest time and update s_nearest_time + */ +void bsc_prepare_timers() +{ + struct timer_list *timer, *nearest_timer = NULL; + llist_for_each_entry(timer, &timer_list, entry) { + if (!nearest_timer || TIME_SMALLER(timer->timeout, nearest_timer->timeout)) { + nearest_timer = timer; + } + } + + if (nearest_timer) { + s_nearest_time = nearest_timer->timeout; + } else { + memset(&s_nearest_time, 0, sizeof(struct timeval)); + } +} + +/* + * fire all timers... and remove them + */ +int bsc_update_timers() +{ + struct timeval current_time; + struct timer_list *timer, *tmp; + int work = 0; + + gettimeofday(¤t_time, NULL); + + /* + * The callbacks might mess with our list and in this case + * even llist_for_each_entry_safe is not safe to use. To allow + * del_timer, add_timer, schedule_timer to be called from within + * the callback we jump through some loops. + * + * First we set the handled flag of each active timer to zero, + * then we iterate over the list and execute the callbacks. As the + * list might have been changed (specially the next) from within + * the callback we have to start over again. Once every callback + * is dispatched we will remove the non-active from the list. + * + * TODO: If this is a performance issue we can poison a global + * variable in add_timer and del_timer and only then restart. + */ + llist_for_each_entry(timer, &timer_list, entry) { + timer->handled = 0; + } + +restart: + llist_for_each_entry(timer, &timer_list, entry) { + if (!timer->handled && TIME_SMALLER(timer->timeout, current_time)) { + timer->handled = 1; + timer->active = 0; + (*timer->cb)(timer->data); + work = 1; + goto restart; + } + } + + llist_for_each_entry_safe(timer, tmp, &timer_list, entry) { + timer->handled = 0; + if (!timer->active) { + bsc_del_timer(timer); + } + } + + return work; +} + +int bsc_timer_check(void) +{ + struct timer_list *timer; + int i = 0; + + llist_for_each_entry(timer, &timer_list, entry) { + i++; + } + return i; +} -- cgit v1.2.3