timer.c

bind 9.3结合mysql数据库

					  timer,
					  ISC_TIMEREVENT_FIRSTEVENT,
					  ISC_TIMEREVENT_LASTEVENT,
					  NULL);
	timer->type = type;
	timer->expires = *expires;
	timer->interval = *interval;
	if (type == isc_timertype_once && !isc_interval_iszero(interval)) {
		result = isc_time_add(&now, interval, &timer->idle);
	} else {
		isc_time_settoepoch(&timer->idle);
		result = ISC_R_SUCCESS;
	}

	if (result == ISC_R_SUCCESS) {
		if (type == isc_timertype_inactive) {
			deschedule(timer);
			result = ISC_R_SUCCESS;
		} else
			result = schedule(timer, &now, ISC_TRUE);
	}

	UNLOCK(&timer->lock);
	UNLOCK(&manager->lock);

	return (result);
}

isc_result_t
isc_timer_gettype(isc_timer_t *timer) {
	isc_timertype_t t;

	REQUIRE(VALID_TIMER(timer));

	LOCK(&timer->lock);
	t = timer->type;
	UNLOCK(&timer->lock);

	return (t);
}

isc_result_t
isc_timer_touch(isc_timer_t *timer) {
	isc_result_t result;
	isc_time_t now;

	/*
	 * Set the last-touched time of 'timer' to the current time.
	 */

	REQUIRE(VALID_TIMER(timer));

	LOCK(&timer->lock);

	/*
	 * We'd like to
	 *
	 *	REQUIRE(timer->type == isc_timertype_once);
	 *
	 * but we cannot without locking the manager lock too, which we
	 * don't want to do.
	 */

	TIME_NOW(&now);
	result = isc_time_add(&now, &timer->interval, &timer->idle);

	UNLOCK(&timer->lock);

	return (result);
}

void
isc_timer_attach(isc_timer_t *timer, isc_timer_t **timerp) {
	/*
	 * Attach *timerp to timer.
	 */

	REQUIRE(VALID_TIMER(timer));
	REQUIRE(timerp != NULL && *timerp == NULL);

	LOCK(&timer->lock);
	timer->references++;
	UNLOCK(&timer->lock);

	*timerp = timer;
}

void
isc_timer_detach(isc_timer_t **timerp) {
	isc_timer_t *timer;
	isc_boolean_t free_timer = ISC_FALSE;

	/*
	 * Detach *timerp from its timer.
	 */

	REQUIRE(timerp != NULL);
	timer = *timerp;
	REQUIRE(VALID_TIMER(timer));

	LOCK(&timer->lock);
	REQUIRE(timer->references > 0);
	timer->references--;
	if (timer->references == 0)
		free_timer = ISC_TRUE;
	UNLOCK(&timer->lock);

	if (free_timer)
		destroy(timer);

	*timerp = NULL;
}

static void
dispatch(isc_timermgr_t *manager, isc_time_t *now) {
	isc_boolean_t done = ISC_FALSE, post_event, need_schedule;
	isc_event_t *event;
	isc_eventtype_t type = 0;
	isc_timer_t *timer;
	isc_result_t result;

	/*
	 * The caller must be holding the manager lock.
	 */

	while (manager->nscheduled > 0 && !done) {
		timer = isc_heap_element(manager->heap, 1);
		INSIST(timer->type != isc_timertype_inactive);
		if (isc_time_compare(now, &timer->due) >= 0) {
			if (timer->type == isc_timertype_ticker) {
				type = ISC_TIMEREVENT_TICK;
				post_event = ISC_TRUE;
				need_schedule = ISC_TRUE;
			} else if (timer->type == isc_timertype_limited) {
				int cmp;
				cmp = isc_time_compare(now, &timer->expires);
				if (cmp >= 0) {
					type = ISC_TIMEREVENT_LIFE;
					post_event = ISC_TRUE;
					need_schedule = ISC_FALSE;
				} else {
					type = ISC_TIMEREVENT_TICK;
					post_event = ISC_TRUE;
					need_schedule = ISC_TRUE;
				}
			} else if (!isc_time_isepoch(&timer->expires) &&
				   isc_time_compare(now,
						    &timer->expires) >= 0) {
				type = ISC_TIMEREVENT_LIFE;
				post_event = ISC_TRUE;
				need_schedule = ISC_FALSE;
			} else if (!isc_time_isepoch(&timer->idle) &&
				   isc_time_compare(now,
						    &timer->idle) >= 0) {
				type = ISC_TIMEREVENT_IDLE;
				post_event = ISC_TRUE;
				need_schedule = ISC_FALSE;
			} else {
				/*
				 * Idle timer has been touched; reschedule.
				 */
				XTRACEID(isc_msgcat_get(isc_msgcat,
							ISC_MSGSET_TIMER,
							ISC_MSG_IDLERESCHED,
							"idle reschedule"),
					 timer);
				post_event = ISC_FALSE;
				need_schedule = ISC_TRUE;
			}

			if (post_event) {
				XTRACEID(isc_msgcat_get(isc_msgcat,
							ISC_MSGSET_TIMER,
							ISC_MSG_POSTING,
							"posting"), timer);
				/*
				 * XXX We could preallocate this event.
				 */
				event = isc_event_allocate(manager->mctx,
							   timer,
							   type,
							   timer->action,
							   timer->arg,
							   sizeof(*event));

				if (event != NULL)
					isc_task_send(timer->task, &event);
				else
					UNEXPECTED_ERROR(__FILE__, __LINE__,
						 isc_msgcat_get(isc_msgcat,
							 ISC_MSGSET_TIMER,
							 ISC_MSG_EVENTNOTALLOC,
							 "couldn't "
							 "allocate event"));
			}

			timer->index = 0;
			isc_heap_delete(manager->heap, 1);
			manager->nscheduled--;

			if (need_schedule) {
				result = schedule(timer, now, ISC_FALSE);
				if (result != ISC_R_SUCCESS)
					UNEXPECTED_ERROR(__FILE__, __LINE__,
						isc_msgcat_get(isc_msgcat,
							ISC_MSGSET_TIMER,
							ISC_MSG_SCHEDFAIL,
							"couldn't "
							"schedule timer: %u"),
							 result);
			}
		} else {
			manager->due = timer->due;
			done = ISC_TRUE;
		}
	}
}

#ifdef ISC_PLATFORM_USETHREADS
static isc_threadresult_t
#ifdef _WIN32			/* XXXDCL */
WINAPI
#endif
run(void *uap) {
	isc_timermgr_t *manager = uap;
	isc_time_t now;
	isc_result_t result;

	LOCK(&manager->lock);
	while (!manager->done) {
		TIME_NOW(&now);

		XTRACETIME(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
					  ISC_MSG_RUNNING,
					  "running"), now);

		dispatch(manager, &now);

		if (manager->nscheduled > 0) {
			XTRACETIME2(isc_msgcat_get(isc_msgcat,
						   ISC_MSGSET_GENERAL,
						   ISC_MSG_WAITUNTIL,
						   "waituntil"),
				    manager->due, now);
			result = WAITUNTIL(&manager->wakeup, &manager->lock, &manager->due);
			INSIST(result == ISC_R_SUCCESS ||
			       result == ISC_R_TIMEDOUT);
		} else {
			XTRACETIME(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
						  ISC_MSG_WAIT, "wait"), now);
			WAIT(&manager->wakeup, &manager->lock);
		}
		XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
				      ISC_MSG_WAKEUP, "wakeup"));
	}
	UNLOCK(&manager->lock);

	return ((isc_threadresult_t)0);
}
#endif /* ISC_PLATFORM_USETHREADS */

static isc_boolean_t
sooner(void *v1, void *v2) {
	isc_timer_t *t1, *t2;

	t1 = v1;
	t2 = v2;
	REQUIRE(VALID_TIMER(t1));
	REQUIRE(VALID_TIMER(t2));

	if (isc_time_compare(&t1->due, &t2->due) < 0)
		return (ISC_TRUE);
	return (ISC_FALSE);
}

static void
set_index(void *what, unsigned int index) {
	isc_timer_t *timer;

	timer = what;
	REQUIRE(VALID_TIMER(timer));

	timer->index = index;
}

isc_result_t
isc_timermgr_create(isc_mem_t *mctx, isc_timermgr_t **managerp) {
	isc_timermgr_t *manager;
	isc_result_t result;

	/*
	 * Create a timer manager.
	 */

	REQUIRE(managerp != NULL && *managerp == NULL);

#ifndef ISC_PLATFORM_USETHREADS
	if (timermgr != NULL) {
		timermgr->refs++;
		*managerp = timermgr;
		return (ISC_R_SUCCESS);
	}
#endif /* ISC_PLATFORM_USETHREADS */

	manager = isc_mem_get(mctx, sizeof(*manager));
	if (manager == NULL)
		return (ISC_R_NOMEMORY);

	manager->magic = TIMER_MANAGER_MAGIC;
	manager->mctx = NULL;
	manager->done = ISC_FALSE;
	INIT_LIST(manager->timers);
	manager->nscheduled = 0;
	isc_time_settoepoch(&manager->due);
	manager->heap = NULL;
	result = isc_heap_create(mctx, sooner, set_index, 0, &manager->heap);
	if (result != ISC_R_SUCCESS) {
		INSIST(result == ISC_R_NOMEMORY);
		isc_mem_put(mctx, manager, sizeof(*manager));
		return (ISC_R_NOMEMORY);
	}
	if (isc_mutex_init(&manager->lock) != ISC_R_SUCCESS) {
		isc_heap_destroy(&manager->heap);
		isc_mem_put(mctx, manager, sizeof(*manager));
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_mutex_init() %s",
				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
						ISC_MSG_FAILED, "failed"));
		return (ISC_R_UNEXPECTED);
	}
	isc_mem_attach(mctx, &manager->mctx);
#ifdef ISC_PLATFORM_USETHREADS
	if (isc_condition_init(&manager->wakeup) != ISC_R_SUCCESS) {
		isc_mem_detach(&manager->mctx);
		DESTROYLOCK(&manager->lock);
		isc_heap_destroy(&manager->heap);
		isc_mem_put(mctx, manager, sizeof(*manager));
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_condition_init() %s",
				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
						ISC_MSG_FAILED, "failed"));
		return (ISC_R_UNEXPECTED);
	}
	if (isc_thread_create(run, manager, &manager->thread) !=
	    ISC_R_SUCCESS) {
		isc_mem_detach(&manager->mctx);
		(void)isc_condition_destroy(&manager->wakeup);
		DESTROYLOCK(&manager->lock);
		isc_heap_destroy(&manager->heap);
		isc_mem_put(mctx, manager, sizeof(*manager));
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_thread_create() %s",
				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
						ISC_MSG_FAILED, "failed"));
		return (ISC_R_UNEXPECTED);
	}
#else /* ISC_PLATFORM_USETHREADS */
	manager->refs = 1;
	timermgr = manager;
#endif /* ISC_PLATFORM_USETHREADS */

	*managerp = manager;

	return (ISC_R_SUCCESS);
}

void
isc_timermgr_poke(isc_timermgr_t *manager) {
#ifdef ISC_PLATFORM_USETHREADS
	REQUIRE(VALID_MANAGER(manager));

	SIGNAL(&manager->wakeup);
#else
	UNUSED(manager);
#endif
}

void
isc_timermgr_destroy(isc_timermgr_t **managerp) {
	isc_timermgr_t *manager;
	isc_mem_t *mctx;

	/*
	 * Destroy a timer manager.
	 */

	REQUIRE(managerp != NULL);
	manager = *managerp;
	REQUIRE(VALID_MANAGER(manager));

	LOCK(&manager->lock);

#ifndef ISC_PLATFORM_USETHREADS
	if (manager->refs > 1) {
		manager->refs--;
		UNLOCK(&manager->lock);
		*managerp = NULL;
		return;
	}

	isc__timermgr_dispatch();
#endif /* ISC_PLATFORM_USETHREADS */

	REQUIRE(EMPTY(manager->timers));
	manager->done = ISC_TRUE;

#ifdef ISC_PLATFORM_USETHREADS
	XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
			      ISC_MSG_SIGNALDESTROY, "signal (destroy)"));
	SIGNAL(&manager->wakeup);
#endif /* ISC_PLATFORM_USETHREADS */

	UNLOCK(&manager->lock);

#ifdef ISC_PLATFORM_USETHREADS
	/*
	 * Wait for thread to exit.
	 */
	if (isc_thread_join(manager->thread, NULL) != ISC_R_SUCCESS)
		UNEXPECTED_ERROR(__FILE__, __LINE__,
				 "isc_thread_join() %s",
				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
						ISC_MSG_FAILED, "failed"));
#endif /* ISC_PLATFORM_USETHREADS */

	/*
	 * Clean up.
	 */
#ifdef ISC_PLATFORM_USETHREADS
	(void)isc_condition_destroy(&manager->wakeup);
#endif /* ISC_PLATFORM_USETHREADS */
	DESTROYLOCK(&manager->lock);
	isc_heap_destroy(&manager->heap);
	manager->magic = 0;
	mctx = manager->mctx;
	isc_mem_put(mctx, manager, sizeof(*manager));
	isc_mem_detach(&mctx);

	*managerp = NULL;
}

#ifndef ISC_PLATFORM_USETHREADS
isc_result_t
isc__timermgr_nextevent(isc_time_t *when) {
	if (timermgr == NULL || timermgr->nscheduled == 0)
		return (ISC_R_NOTFOUND);
	*when = timermgr->due;
	return (ISC_R_SUCCESS);
}

void
isc__timermgr_dispatch(void) {
	isc_time_t now;
	if (timermgr == NULL)
		return;
	TIME_NOW(&now);
	dispatch(timermgr, &now);
}
#endif /* ISC_PLATFORM_USETHREADS */