diff options
Diffstat (limited to 'src/common/timers.c')
| -rw-r--r-- | src/common/timers.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/src/common/timers.c b/src/common/timers.c index 5f42cd45ba..58981b9588 100644 --- a/src/common/timers.c +++ b/src/common/timers.c @@ -79,12 +79,23 @@ static struct event *global_timer_event = NULL; /** We need to choose this value carefully. Because we're using timer wheels, * it actually costs us to have extra resolution we don't use. So for now, * I'm going to define our resolution as .1 msec, and hope that's good enough. + * + * Note that two of the most popular libevent backends (epoll without timerfd, + * and windows select), simply can't support sub-millisecond resolution, + * do this is optimistic for a lot of users. */ #define USEC_PER_TICK 100 /** One million microseconds in a second */ #define USEC_PER_SEC 1000000 +/** Check at least once every N seconds. */ +#define MIN_CHECK_SECONDS 3600 + +/** Check at least once every N ticks. */ +#define MIN_CHECK_TICKS \ + (((timeout_t)MIN_CHECK_SECONDS) * (1000000 / USEC_PER_TICK)) + /** * Convert the timeval in <b>tv</b> to a timeout_t, and return it. * @@ -135,8 +146,10 @@ libevent_timer_reschedule(void) tor_gettimeofday_cached_monotonic(&now); timer_advance_to_cur_time(&now); - const timeout_t delay = timeouts_timeout(global_timeouts); + timeout_t delay = timeouts_timeout(global_timeouts); struct timeval d; + if (delay > MIN_CHECK_TICKS) + delay = MIN_CHECK_TICKS; timeout_to_tv(delay, &d); event_add(global_timer_event, &d); } @@ -153,6 +166,7 @@ libevent_timer_callback(evutil_socket_t fd, short what, void *arg) (void)arg; struct timeval now; + tor_gettimeofday_cache_clear(); tor_gettimeofday_cached_monotonic(&now); timer_advance_to_cur_time(&now); @@ -187,6 +201,8 @@ timers_initialize(void) -1, 0, libevent_timer_callback, NULL); tor_assert(timer_event); global_timer_event = timer_event; + + libevent_timer_reschedule(); } /** @@ -253,12 +269,15 @@ timer_schedule(tor_timer_t *t, const struct timeval *tv) tor_gettimeofday_cached_monotonic(&now); timer_advance_to_cur_time(&now); + /* Take the old timeout value. */ + timeout_t to = timeouts_timeout(global_timeouts); + timeouts_add(global_timeouts, t, when); /* Should we update the libevent timer? */ if (to <= when) { return; /* we're already going to fire before this timer would trigger. */ - + } libevent_timer_reschedule(); } |