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Diffstat (limited to '')
| -rw-r--r-- | interval.h | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/interval.h b/interval.h new file mode 100644 index 0000000..9845066 --- /dev/null +++ b/interval.h @@ -0,0 +1,239 @@ +/* + * OpenVPN -- An application to securely tunnel IP networks + * over a single TCP/UDP port, with support for SSL/TLS-based + * session authentication and key exchange, + * packet encryption, packet authentication, and + * packet compression. + * + * Copyright (C) 2002-2005 OpenVPN Solutions LLC <info@openvpn.net> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * 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 (see the file COPYING included with this + * distribution); if not, write to the Free Software Foundation, Inc., + * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +/* + * The interval_ routines are designed to optimize the calling of a routine + * (normally tls_multi_process()) which can be called less frequently + * between triggers. + */ + +#ifndef INTERVAL_H +#define INTERVAL_H + +#include "otime.h" + +#define INTERVAL_DEBUG 0 + +/* + * Designed to limit calls to expensive functions that need to be called + * regularly. + */ + +struct interval +{ + interval_t refresh; + interval_t horizon; + time_t future_trigger; + time_t last_action; + time_t last_test_true; +}; + +void interval_init (struct interval *top, int horizon, int refresh); + +/* + * IF + * last_action less than horizon seconds ago + * OR last_test_true more than refresh seconds ago + * OR hit future_trigger + * THEN + * return true + * ELSE + * set wakeup to the number of seconds until a true return + * return false + */ + +static inline bool +interval_test (struct interval* top) +{ + bool trigger = false; + const time_t local_now = now; + + if (top->future_trigger && local_now >= top->future_trigger) + { + trigger = true; + top->future_trigger = 0; + } + + if (top->last_action + top->horizon > local_now || + top->last_test_true + top->refresh <= local_now || + trigger) + { + top->last_test_true = local_now; +#if INTERVAL_DEBUG + dmsg (D_INTERVAL, "INTERVAL interval_test true"); +#endif + return true; + } + else + { + return false; + } +} + +static inline void +interval_schedule_wakeup (struct interval* top, interval_t *wakeup) +{ + const time_t local_now = now; + interval_earliest_wakeup (wakeup, top->last_test_true + top->refresh, local_now); + interval_earliest_wakeup (wakeup, top->future_trigger, local_now); +#if INTERVAL_DEBUG + dmsg (D_INTERVAL, "INTERVAL interval_schedule wakeup=%d", (int)*wakeup); +#endif +} + +/* + * In wakeup seconds, interval_test will return true once. + */ +static inline void +interval_future_trigger (struct interval* top, interval_t wakeup) { + if (wakeup) + { +#if INTERVAL_DEBUG + dmsg (D_INTERVAL, "INTERVAL interval_future_trigger %d", (int)wakeup); +#endif + top->future_trigger = now + wakeup; + } +} + +/* + * Once an action is triggered, interval_test will remain true for + * horizon seconds. + */ +static inline void +interval_action (struct interval* top) +{ +#if INTERVAL_DEBUG + dmsg (D_INTERVAL, "INTERVAL action"); +#endif + top->last_action = now; +} + +/* + * Measure when n seconds beyond an event have elapsed + */ + +struct event_timeout +{ + bool defined; + interval_t n; + time_t last; /* time of last event */ +}; + +static inline bool +event_timeout_defined (const struct event_timeout* et) +{ + return et->defined; +} + +static inline void +event_timeout_clear (struct event_timeout* et) +{ + et->defined = false; + et->n = 0; + et->last = 0; +} + +static inline struct event_timeout +event_timeout_clear_ret () +{ + struct event_timeout ret; + event_timeout_clear (&ret); + return ret; +} + +static inline void +event_timeout_init (struct event_timeout* et, interval_t n, const time_t local_now) +{ + et->defined = true; + et->n = (n >= 0) ? n : 0; + et->last = local_now; +} + +static inline void +event_timeout_reset (struct event_timeout* et) +{ + if (et->defined) + et->last = now; +} + +/* + * This is the principal function for testing and triggering recurring + * timers and will return true on a timer signal event. + * If et_const_retry == ETT_DEFAULT and a signal occurs, + * the function will return true and *et will be armed for the + * next event. If et_const_retry >= 0 and a signal occurs, + * *et will not be touched, but *tv will be set to + * minimum (*tv, et_const_retry) for a future re-test, + * and the function will return true. + */ + +#define ETT_DEFAULT (-1) + +bool event_timeout_trigger (struct event_timeout *et, + struct timeval *tv, + const int et_const_retry); + +/* + * Measure time intervals in microseconds + */ + +#define USEC_TIMER_MAX 60 /* maximum interval size in seconds */ + +#define USEC_TIMER_MAX_USEC (USEC_TIMER_MAX * 1000000) + +struct usec_timer { + struct timeval start; + struct timeval end; +}; + +#ifdef HAVE_GETTIMEOFDAY + +static inline void +usec_timer_start (struct usec_timer *obj) +{ + CLEAR (*obj); + gettimeofday (&obj->start, NULL); +} + +static inline void +usec_timer_end (struct usec_timer *obj) +{ + gettimeofday (&obj->end, NULL); +} + +#endif /* HAVE_GETTIMEOFDAY */ + +static inline bool +usec_timer_interval_defined (struct usec_timer *obj) +{ + return obj->start.tv_sec && obj->end.tv_sec; +} + +static inline int +usec_timer_interval (struct usec_timer *obj) +{ + return tv_subtract (&obj->end, &obj->start, USEC_TIMER_MAX); +} + +#endif /* INTERVAL_H */ |