File:  [ELWIX - Embedded LightWeight unIX -] / embedaddon / ntp / lib / isc / timer.c
Revision 1.1.1.1 (vendor branch): download - view: text, annotated - select for diffs - revision graph
Tue May 29 12:08:38 2012 UTC (12 years, 7 months ago) by misho
Branches: ntp, MAIN
CVS tags: v4_2_6p5p0, v4_2_6p5, HEAD
ntp 4.2.6p5

    1: /*
    2:  * Copyright (C) 2004, 2005, 2007-2009  Internet Systems Consortium, Inc. ("ISC")
    3:  * Copyright (C) 1998-2002  Internet Software Consortium.
    4:  *
    5:  * Permission to use, copy, modify, and/or distribute this software for any
    6:  * purpose with or without fee is hereby granted, provided that the above
    7:  * copyright notice and this permission notice appear in all copies.
    8:  *
    9:  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
   10:  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
   11:  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
   12:  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
   13:  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
   14:  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
   15:  * PERFORMANCE OF THIS SOFTWARE.
   16:  */
   17: 
   18: /* $Id: timer.c,v 1.1.1.1 2012/05/29 12:08:38 misho Exp $ */
   19: 
   20: /*! \file */
   21: 
   22: #include <config.h>
   23: 
   24: #include <isc/condition.h>
   25: #include <isc/heap.h>
   26: #include <isc/log.h>
   27: #include <isc/magic.h>
   28: #include <isc/mem.h>
   29: #include <isc/msgs.h>
   30: #include <isc/platform.h>
   31: #include <isc/task.h>
   32: #include <isc/thread.h>
   33: #include <isc/time.h>
   34: #include <isc/timer.h>
   35: #include <isc/util.h>
   36: 
   37: #ifndef ISC_PLATFORM_USETHREADS
   38: #include "timer_p.h"
   39: #endif /* ISC_PLATFORM_USETHREADS */
   40: 
   41: #ifdef ISC_TIMER_TRACE
   42: #define XTRACE(s)			fprintf(stderr, "%s\n", (s))
   43: #define XTRACEID(s, t)			fprintf(stderr, "%s %p\n", (s), (t))
   44: #define XTRACETIME(s, d)		fprintf(stderr, "%s %u.%09u\n", (s), \
   45: 					       (d).seconds, (d).nanoseconds)
   46: #define XTRACETIME2(s, d, n)		fprintf(stderr, "%s %u.%09u %u.%09u\n", (s), \
   47: 					       (d).seconds, (d).nanoseconds, (n).seconds, (n).nanoseconds)
   48: #define XTRACETIMER(s, t, d)		fprintf(stderr, "%s %p %u.%09u\n", (s), (t), \
   49: 					       (d).seconds, (d).nanoseconds)
   50: #else
   51: #define XTRACE(s)
   52: #define XTRACEID(s, t)
   53: #define XTRACETIME(s, d)
   54: #define XTRACETIME2(s, d, n)
   55: #define XTRACETIMER(s, t, d)
   56: #endif /* ISC_TIMER_TRACE */
   57: 
   58: #define TIMER_MAGIC			ISC_MAGIC('T', 'I', 'M', 'R')
   59: #define VALID_TIMER(t)			ISC_MAGIC_VALID(t, TIMER_MAGIC)
   60: 
   61: struct isc_timer {
   62: 	/*! Not locked. */
   63: 	unsigned int			magic;
   64: 	isc_timermgr_t *		manager;
   65: 	isc_mutex_t			lock;
   66: 	/*! Locked by timer lock. */
   67: 	unsigned int			references;
   68: 	isc_time_t			idle;
   69: 	/*! Locked by manager lock. */
   70: 	isc_timertype_t			type;
   71: 	isc_time_t			expires;
   72: 	isc_interval_t			interval;
   73: 	isc_task_t *			task;
   74: 	isc_taskaction_t		action;
   75: 	void *				arg;
   76: 	unsigned int			index;
   77: 	isc_time_t			due;
   78: 	LINK(isc_timer_t)		link;
   79: };
   80: 
   81: #define TIMER_MANAGER_MAGIC		ISC_MAGIC('T', 'I', 'M', 'M')
   82: #define VALID_MANAGER(m)		ISC_MAGIC_VALID(m, TIMER_MANAGER_MAGIC)
   83: 
   84: struct isc_timermgr {
   85: 	/* Not locked. */
   86: 	unsigned int			magic;
   87: 	isc_mem_t *			mctx;
   88: 	isc_mutex_t			lock;
   89: 	/* Locked by manager lock. */
   90: 	isc_boolean_t			done;
   91: 	LIST(isc_timer_t)		timers;
   92: 	unsigned int			nscheduled;
   93: 	isc_time_t			due;
   94: #ifdef ISC_PLATFORM_USETHREADS
   95: 	isc_condition_t			wakeup;
   96: 	isc_thread_t			thread;
   97: #else /* ISC_PLATFORM_USETHREADS */
   98: 	unsigned int			refs;
   99: #endif /* ISC_PLATFORM_USETHREADS */
  100: 	isc_heap_t *			heap;
  101: };
  102: 
  103: #ifndef ISC_PLATFORM_USETHREADS
  104: /*!
  105:  * If threads are not in use, there can be only one.
  106:  */
  107: static isc_timermgr_t *timermgr = NULL;
  108: #endif /* ISC_PLATFORM_USETHREADS */
  109: 
  110: static inline isc_result_t
  111: schedule(isc_timer_t *timer, isc_time_t *now, isc_boolean_t signal_ok) {
  112: 	isc_result_t result;
  113: 	isc_timermgr_t *manager;
  114: 	isc_time_t due;
  115: 	int cmp;
  116: #ifdef ISC_PLATFORM_USETHREADS
  117: 	isc_boolean_t timedwait;
  118: #endif
  119: 
  120: 	/*!
  121: 	 * Note: the caller must ensure locking.
  122: 	 */
  123: 
  124: 	REQUIRE(timer->type != isc_timertype_inactive);
  125: 
  126: #ifndef ISC_PLATFORM_USETHREADS
  127: 	UNUSED(signal_ok);
  128: #endif /* ISC_PLATFORM_USETHREADS */
  129: 
  130: 	manager = timer->manager;
  131: 
  132: #ifdef ISC_PLATFORM_USETHREADS
  133: 	/*!
  134: 	 * If the manager was timed wait, we may need to signal the
  135: 	 * manager to force a wakeup.
  136: 	 */
  137: 	timedwait = ISC_TF(manager->nscheduled > 0 &&
  138: 			   isc_time_seconds(&manager->due) != 0);
  139: #endif
  140: 
  141: 	/*
  142: 	 * Compute the new due time.
  143: 	 */
  144: 	if (timer->type != isc_timertype_once) {
  145: 		result = isc_time_add(now, &timer->interval, &due);
  146: 		if (result != ISC_R_SUCCESS)
  147: 			return (result);
  148: 		if (timer->type == isc_timertype_limited &&
  149: 		    isc_time_compare(&timer->expires, &due) < 0)
  150: 			due = timer->expires;
  151: 	} else {
  152: 		if (isc_time_isepoch(&timer->idle))
  153: 			due = timer->expires;
  154: 		else if (isc_time_isepoch(&timer->expires))
  155: 			due = timer->idle;
  156: 		else if (isc_time_compare(&timer->idle, &timer->expires) < 0)
  157: 			due = timer->idle;
  158: 		else
  159: 			due = timer->expires;
  160: 	}
  161: 
  162: 	/*
  163: 	 * Schedule the timer.
  164: 	 */
  165: 
  166: 	if (timer->index > 0) {
  167: 		/*
  168: 		 * Already scheduled.
  169: 		 */
  170: 		cmp = isc_time_compare(&due, &timer->due);
  171: 		timer->due = due;
  172: 		switch (cmp) {
  173: 		case -1:
  174: 			isc_heap_increased(manager->heap, timer->index);
  175: 			break;
  176: 		case 1:
  177: 			isc_heap_decreased(manager->heap, timer->index);
  178: 			break;
  179: 		case 0:
  180: 			/* Nothing to do. */
  181: 			break;
  182: 		}
  183: 	} else {
  184: 		timer->due = due;
  185: 		result = isc_heap_insert(manager->heap, timer);
  186: 		if (result != ISC_R_SUCCESS) {
  187: 			INSIST(result == ISC_R_NOMEMORY);
  188: 			return (ISC_R_NOMEMORY);
  189: 		}
  190: 		manager->nscheduled++;
  191: 	}
  192: 
  193: 	XTRACETIMER(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
  194: 				   ISC_MSG_SCHEDULE, "schedule"), timer, due);
  195: 
  196: 	/*
  197: 	 * If this timer is at the head of the queue, we need to ensure
  198: 	 * that we won't miss it if it has a more recent due time than
  199: 	 * the current "next" timer.  We do this either by waking up the
  200: 	 * run thread, or explicitly setting the value in the manager.
  201: 	 */
  202: #ifdef ISC_PLATFORM_USETHREADS
  203: 
  204: 	/*
  205: 	 * This is a temporary (probably) hack to fix a bug on tru64 5.1
  206: 	 * and 5.1a.  Sometimes, pthread_cond_timedwait() doesn't actually
  207: 	 * return when the time expires, so here, we check to see if
  208: 	 * we're 15 seconds or more behind, and if we are, we signal
  209: 	 * the dispatcher.  This isn't such a bad idea as a general purpose
  210: 	 * watchdog, so perhaps we should just leave it in here.
  211: 	 */
  212: 	if (signal_ok && timedwait) {
  213: 		isc_interval_t fifteen;
  214: 		isc_time_t then;
  215: 
  216: 		isc_interval_set(&fifteen, 15, 0);
  217: 		result = isc_time_add(&manager->due, &fifteen, &then);
  218: 
  219: 		if (result == ISC_R_SUCCESS &&
  220: 		    isc_time_compare(&then, now) < 0) {
  221: 			SIGNAL(&manager->wakeup);
  222: 			signal_ok = ISC_FALSE;
  223: 			isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL,
  224: 				      ISC_LOGMODULE_TIMER, ISC_LOG_WARNING,
  225: 				      "*** POKED TIMER ***");
  226: 		}
  227: 	}
  228: 
  229: 	if (timer->index == 1 && signal_ok) {
  230: 		XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
  231: 				      ISC_MSG_SIGNALSCHED,
  232: 				      "signal (schedule)"));
  233: 		SIGNAL(&manager->wakeup);
  234: 	}
  235: #else /* ISC_PLATFORM_USETHREADS */
  236: 	if (timer->index == 1 &&
  237: 	    isc_time_compare(&timer->due, &manager->due) < 0)
  238: 		manager->due = timer->due;
  239: #endif /* ISC_PLATFORM_USETHREADS */
  240: 
  241: 	return (ISC_R_SUCCESS);
  242: }
  243: 
  244: static inline void
  245: deschedule(isc_timer_t *timer) {
  246: 	isc_boolean_t need_wakeup = ISC_FALSE;
  247: 	isc_timermgr_t *manager;
  248: 
  249: 	/*
  250: 	 * The caller must ensure locking.
  251: 	 */
  252: 
  253: 	manager = timer->manager;
  254: 	if (timer->index > 0) {
  255: 		if (timer->index == 1)
  256: 			need_wakeup = ISC_TRUE;
  257: 		isc_heap_delete(manager->heap, timer->index);
  258: 		timer->index = 0;
  259: 		INSIST(manager->nscheduled > 0);
  260: 		manager->nscheduled--;
  261: #ifdef ISC_PLATFORM_USETHREADS
  262: 		if (need_wakeup) {
  263: 			XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
  264: 					      ISC_MSG_SIGNALDESCHED,
  265: 					      "signal (deschedule)"));
  266: 			SIGNAL(&manager->wakeup);
  267: 		}
  268: #endif /* ISC_PLATFORM_USETHREADS */
  269: 	}
  270: }
  271: 
  272: static void
  273: destroy(isc_timer_t *timer) {
  274: 	isc_timermgr_t *manager = timer->manager;
  275: 
  276: 	/*
  277: 	 * The caller must ensure it is safe to destroy the timer.
  278: 	 */
  279: 
  280: 	LOCK(&manager->lock);
  281: 
  282: 	(void)isc_task_purgerange(timer->task,
  283: 				  timer,
  284: 				  ISC_TIMEREVENT_FIRSTEVENT,
  285: 				  ISC_TIMEREVENT_LASTEVENT,
  286: 				  NULL);
  287: 	deschedule(timer);
  288: 	UNLINK(manager->timers, timer, link);
  289: 
  290: 	UNLOCK(&manager->lock);
  291: 
  292: 	isc_task_detach(&timer->task);
  293: 	DESTROYLOCK(&timer->lock);
  294: 	timer->magic = 0;
  295: 	isc_mem_put(manager->mctx, timer, sizeof(*timer));
  296: }
  297: 
  298: isc_result_t
  299: isc_timer_create(isc_timermgr_t *manager, isc_timertype_t type,
  300: 		 isc_time_t *expires, isc_interval_t *interval,
  301: 		 isc_task_t *task, isc_taskaction_t action, const void *arg,
  302: 		 isc_timer_t **timerp)
  303: {
  304: 	isc_timer_t *timer;
  305: 	isc_result_t result;
  306: 	isc_time_t now;
  307: 
  308: 	/*
  309: 	 * Create a new 'type' timer managed by 'manager'.  The timers
  310: 	 * parameters are specified by 'expires' and 'interval'.  Events
  311: 	 * will be posted to 'task' and when dispatched 'action' will be
  312: 	 * called with 'arg' as the arg value.  The new timer is returned
  313: 	 * in 'timerp'.
  314: 	 */
  315: 
  316: 	REQUIRE(VALID_MANAGER(manager));
  317: 	REQUIRE(task != NULL);
  318: 	REQUIRE(action != NULL);
  319: 	if (expires == NULL)
  320: 		expires = isc_time_epoch;
  321: 	if (interval == NULL)
  322: 		interval = isc_interval_zero;
  323: 	REQUIRE(type == isc_timertype_inactive ||
  324: 		!(isc_time_isepoch(expires) && isc_interval_iszero(interval)));
  325: 	REQUIRE(timerp != NULL && *timerp == NULL);
  326: 	REQUIRE(type != isc_timertype_limited ||
  327: 		!(isc_time_isepoch(expires) || isc_interval_iszero(interval)));
  328: 
  329: 	/*
  330: 	 * Get current time.
  331: 	 */
  332: 	if (type != isc_timertype_inactive) {
  333: 		TIME_NOW(&now);
  334: 	} else {
  335: 		/*
  336: 		 * We don't have to do this, but it keeps the compiler from
  337: 		 * complaining about "now" possibly being used without being
  338: 		 * set, even though it will never actually happen.
  339: 		 */
  340: 		isc_time_settoepoch(&now);
  341: 	}
  342: 
  343: 
  344: 	timer = isc_mem_get(manager->mctx, sizeof(*timer));
  345: 	if (timer == NULL)
  346: 		return (ISC_R_NOMEMORY);
  347: 
  348: 	timer->manager = manager;
  349: 	timer->references = 1;
  350: 
  351: 	if (type == isc_timertype_once && !isc_interval_iszero(interval)) {
  352: 		result = isc_time_add(&now, interval, &timer->idle);
  353: 		if (result != ISC_R_SUCCESS) {
  354: 			isc_mem_put(manager->mctx, timer, sizeof(*timer));
  355: 			return (result);
  356: 		}
  357: 	} else
  358: 		isc_time_settoepoch(&timer->idle);
  359: 
  360: 	timer->type = type;
  361: 	timer->expires = *expires;
  362: 	timer->interval = *interval;
  363: 	timer->task = NULL;
  364: 	isc_task_attach(task, &timer->task);
  365: 	timer->action = action;
  366: 	/*
  367: 	 * Removing the const attribute from "arg" is the best of two
  368: 	 * evils here.  If the timer->arg member is made const, then
  369: 	 * it affects a great many recipients of the timer event
  370: 	 * which did not pass in an "arg" that was truly const.
  371: 	 * Changing isc_timer_create() to not have "arg" prototyped as const,
  372: 	 * though, can cause compilers warnings for calls that *do*
  373: 	 * have a truly const arg.  The caller will have to carefully
  374: 	 * keep track of whether arg started as a true const.
  375: 	 */
  376: 	DE_CONST(arg, timer->arg);
  377: 	timer->index = 0;
  378: 	result = isc_mutex_init(&timer->lock);
  379: 	if (result != ISC_R_SUCCESS) {
  380: 		isc_task_detach(&timer->task);
  381: 		isc_mem_put(manager->mctx, timer, sizeof(*timer));
  382: 		return (result);
  383: 	}
  384: 	ISC_LINK_INIT(timer, link);
  385: 	timer->magic = TIMER_MAGIC;
  386: 
  387: 	LOCK(&manager->lock);
  388: 
  389: 	/*
  390: 	 * Note we don't have to lock the timer like we normally would because
  391: 	 * there are no external references to it yet.
  392: 	 */
  393: 
  394: 	if (type != isc_timertype_inactive)
  395: 		result = schedule(timer, &now, ISC_TRUE);
  396: 	else
  397: 		result = ISC_R_SUCCESS;
  398: 	if (result == ISC_R_SUCCESS)
  399: 		APPEND(manager->timers, timer, link);
  400: 
  401: 	UNLOCK(&manager->lock);
  402: 
  403: 	if (result != ISC_R_SUCCESS) {
  404: 		timer->magic = 0;
  405: 		DESTROYLOCK(&timer->lock);
  406: 		isc_task_detach(&timer->task);
  407: 		isc_mem_put(manager->mctx, timer, sizeof(*timer));
  408: 		return (result);
  409: 	}
  410: 
  411: 	*timerp = timer;
  412: 
  413: 	return (ISC_R_SUCCESS);
  414: }
  415: 
  416: isc_result_t
  417: isc_timer_reset(isc_timer_t *timer, isc_timertype_t type,
  418: 		isc_time_t *expires, isc_interval_t *interval,
  419: 		isc_boolean_t purge)
  420: {
  421: 	isc_time_t now;
  422: 	isc_timermgr_t *manager;
  423: 	isc_result_t result;
  424: 
  425: 	/*
  426: 	 * Change the timer's type, expires, and interval values to the given
  427: 	 * values.  If 'purge' is ISC_TRUE, any pending events from this timer
  428: 	 * are purged from its task's event queue.
  429: 	 */
  430: 
  431: 	REQUIRE(VALID_TIMER(timer));
  432: 	manager = timer->manager;
  433: 	REQUIRE(VALID_MANAGER(manager));
  434: 	if (expires == NULL)
  435: 		expires = isc_time_epoch;
  436: 	if (interval == NULL)
  437: 		interval = isc_interval_zero;
  438: 	REQUIRE(type == isc_timertype_inactive ||
  439: 		!(isc_time_isepoch(expires) && isc_interval_iszero(interval)));
  440: 	REQUIRE(type != isc_timertype_limited ||
  441: 		!(isc_time_isepoch(expires) || isc_interval_iszero(interval)));
  442: 
  443: 	/*
  444: 	 * Get current time.
  445: 	 */
  446: 	if (type != isc_timertype_inactive) {
  447: 		TIME_NOW(&now);
  448: 	} else {
  449: 		/*
  450: 		 * We don't have to do this, but it keeps the compiler from
  451: 		 * complaining about "now" possibly being used without being
  452: 		 * set, even though it will never actually happen.
  453: 		 */
  454: 		isc_time_settoepoch(&now);
  455: 	}
  456: 
  457: 	manager = timer->manager;
  458: 
  459: 	LOCK(&manager->lock);
  460: 	LOCK(&timer->lock);
  461: 
  462: 	if (purge)
  463: 		(void)isc_task_purgerange(timer->task,
  464: 					  timer,
  465: 					  ISC_TIMEREVENT_FIRSTEVENT,
  466: 					  ISC_TIMEREVENT_LASTEVENT,
  467: 					  NULL);
  468: 	timer->type = type;
  469: 	timer->expires = *expires;
  470: 	timer->interval = *interval;
  471: 	if (type == isc_timertype_once && !isc_interval_iszero(interval)) {
  472: 		result = isc_time_add(&now, interval, &timer->idle);
  473: 	} else {
  474: 		isc_time_settoepoch(&timer->idle);
  475: 		result = ISC_R_SUCCESS;
  476: 	}
  477: 
  478: 	if (result == ISC_R_SUCCESS) {
  479: 		if (type == isc_timertype_inactive) {
  480: 			deschedule(timer);
  481: 			result = ISC_R_SUCCESS;
  482: 		} else
  483: 			result = schedule(timer, &now, ISC_TRUE);
  484: 	}
  485: 
  486: 	UNLOCK(&timer->lock);
  487: 	UNLOCK(&manager->lock);
  488: 
  489: 	return (result);
  490: }
  491: 
  492: isc_timertype_t
  493: isc_timer_gettype(isc_timer_t *timer) {
  494: 	isc_timertype_t t;
  495: 
  496: 	REQUIRE(VALID_TIMER(timer));
  497: 
  498: 	LOCK(&timer->lock);
  499: 	t = timer->type;
  500: 	UNLOCK(&timer->lock);
  501: 
  502: 	return (t);
  503: }
  504: 
  505: isc_result_t
  506: isc_timer_touch(isc_timer_t *timer) {
  507: 	isc_result_t result;
  508: 	isc_time_t now;
  509: 
  510: 	/*
  511: 	 * Set the last-touched time of 'timer' to the current time.
  512: 	 */
  513: 
  514: 	REQUIRE(VALID_TIMER(timer));
  515: 
  516: 	LOCK(&timer->lock);
  517: 
  518: 	/*
  519: 	 * We'd like to
  520: 	 *
  521: 	 *	REQUIRE(timer->type == isc_timertype_once);
  522: 	 *
  523: 	 * but we cannot without locking the manager lock too, which we
  524: 	 * don't want to do.
  525: 	 */
  526: 
  527: 	TIME_NOW(&now);
  528: 	result = isc_time_add(&now, &timer->interval, &timer->idle);
  529: 
  530: 	UNLOCK(&timer->lock);
  531: 
  532: 	return (result);
  533: }
  534: 
  535: void
  536: isc_timer_attach(isc_timer_t *timer, isc_timer_t **timerp) {
  537: 	/*
  538: 	 * Attach *timerp to timer.
  539: 	 */
  540: 
  541: 	REQUIRE(VALID_TIMER(timer));
  542: 	REQUIRE(timerp != NULL && *timerp == NULL);
  543: 
  544: 	LOCK(&timer->lock);
  545: 	timer->references++;
  546: 	UNLOCK(&timer->lock);
  547: 
  548: 	*timerp = timer;
  549: }
  550: 
  551: void
  552: isc_timer_detach(isc_timer_t **timerp) {
  553: 	isc_timer_t *timer;
  554: 	isc_boolean_t free_timer = ISC_FALSE;
  555: 
  556: 	/*
  557: 	 * Detach *timerp from its timer.
  558: 	 */
  559: 
  560: 	REQUIRE(timerp != NULL);
  561: 	timer = *timerp;
  562: 	REQUIRE(VALID_TIMER(timer));
  563: 
  564: 	LOCK(&timer->lock);
  565: 	REQUIRE(timer->references > 0);
  566: 	timer->references--;
  567: 	if (timer->references == 0)
  568: 		free_timer = ISC_TRUE;
  569: 	UNLOCK(&timer->lock);
  570: 
  571: 	if (free_timer)
  572: 		destroy(timer);
  573: 
  574: 	*timerp = NULL;
  575: }
  576: 
  577: static void
  578: dispatch(isc_timermgr_t *manager, isc_time_t *now) {
  579: 	isc_boolean_t done = ISC_FALSE, post_event, need_schedule;
  580: 	isc_timerevent_t *event;
  581: 	isc_eventtype_t type = 0;
  582: 	isc_timer_t *timer;
  583: 	isc_result_t result;
  584: 	isc_boolean_t idle;
  585: 
  586: 	/*!
  587: 	 * The caller must be holding the manager lock.
  588: 	 */
  589: 
  590: 	while (manager->nscheduled > 0 && !done) {
  591: 		timer = isc_heap_element(manager->heap, 1);
  592: 		INSIST(timer->type != isc_timertype_inactive);
  593: 		if (isc_time_compare(now, &timer->due) >= 0) {
  594: 			if (timer->type == isc_timertype_ticker) {
  595: 				type = ISC_TIMEREVENT_TICK;
  596: 				post_event = ISC_TRUE;
  597: 				need_schedule = ISC_TRUE;
  598: 			} else if (timer->type == isc_timertype_limited) {
  599: 				int cmp;
  600: 				cmp = isc_time_compare(now, &timer->expires);
  601: 				if (cmp >= 0) {
  602: 					type = ISC_TIMEREVENT_LIFE;
  603: 					post_event = ISC_TRUE;
  604: 					need_schedule = ISC_FALSE;
  605: 				} else {
  606: 					type = ISC_TIMEREVENT_TICK;
  607: 					post_event = ISC_TRUE;
  608: 					need_schedule = ISC_TRUE;
  609: 				}
  610: 			} else if (!isc_time_isepoch(&timer->expires) &&
  611: 				   isc_time_compare(now,
  612: 						    &timer->expires) >= 0) {
  613: 				type = ISC_TIMEREVENT_LIFE;
  614: 				post_event = ISC_TRUE;
  615: 				need_schedule = ISC_FALSE;
  616: 			} else {
  617: 				idle = ISC_FALSE;
  618: 
  619: 				LOCK(&timer->lock);
  620: 				if (!isc_time_isepoch(&timer->idle) &&
  621: 				    isc_time_compare(now,
  622: 						     &timer->idle) >= 0) {
  623: 					idle = ISC_TRUE;
  624: 				}
  625: 				UNLOCK(&timer->lock);
  626: 				if (idle) {
  627: 					type = ISC_TIMEREVENT_IDLE;
  628: 					post_event = ISC_TRUE;
  629: 					need_schedule = ISC_FALSE;
  630: 				} else {
  631: 					/*
  632: 					 * Idle timer has been touched;
  633: 					 * reschedule.
  634: 					 */
  635: 					XTRACEID(isc_msgcat_get(isc_msgcat,
  636: 								ISC_MSGSET_TIMER,
  637: 								ISC_MSG_IDLERESCHED,
  638: 								"idle reschedule"),
  639: 						 timer);
  640: 					post_event = ISC_FALSE;
  641: 					need_schedule = ISC_TRUE;
  642: 				}
  643: 			}
  644: 
  645: 			if (post_event) {
  646: 				XTRACEID(isc_msgcat_get(isc_msgcat,
  647: 							ISC_MSGSET_TIMER,
  648: 							ISC_MSG_POSTING,
  649: 							"posting"), timer);
  650: 				/*
  651: 				 * XXX We could preallocate this event.
  652: 				 */
  653: 				event = (isc_timerevent_t *)isc_event_allocate(manager->mctx,
  654: 							   timer,
  655: 							   type,
  656: 							   timer->action,
  657: 							   timer->arg,
  658: 							   sizeof(*event));
  659: 
  660: 				if (event != NULL) {
  661: 					event->due = timer->due;
  662: 					isc_task_send(timer->task,
  663: 						      ISC_EVENT_PTR(&event));
  664: 				} else
  665: 					UNEXPECTED_ERROR(__FILE__, __LINE__, "%s",
  666: 						 isc_msgcat_get(isc_msgcat,
  667: 							 ISC_MSGSET_TIMER,
  668: 							 ISC_MSG_EVENTNOTALLOC,
  669: 							 "couldn't "
  670: 							 "allocate event"));
  671: 			}
  672: 
  673: 			timer->index = 0;
  674: 			isc_heap_delete(manager->heap, 1);
  675: 			manager->nscheduled--;
  676: 
  677: 			if (need_schedule) {
  678: 				result = schedule(timer, now, ISC_FALSE);
  679: 				if (result != ISC_R_SUCCESS)
  680: 					UNEXPECTED_ERROR(__FILE__, __LINE__,
  681: 							 "%s: %u",
  682: 						isc_msgcat_get(isc_msgcat,
  683: 							ISC_MSGSET_TIMER,
  684: 							ISC_MSG_SCHEDFAIL,
  685: 							"couldn't schedule "
  686: 							"timer"),
  687: 							 result);
  688: 			}
  689: 		} else {
  690: 			manager->due = timer->due;
  691: 			done = ISC_TRUE;
  692: 		}
  693: 	}
  694: }
  695: 
  696: #ifdef ISC_PLATFORM_USETHREADS
  697: static isc_threadresult_t
  698: #ifdef _WIN32			/* XXXDCL */
  699: WINAPI
  700: #endif
  701: run(void *uap) {
  702: 	isc_timermgr_t *manager = uap;
  703: 	isc_time_t now;
  704: 	isc_result_t result;
  705: 
  706: 	LOCK(&manager->lock);
  707: 	while (!manager->done) {
  708: 		TIME_NOW(&now);
  709: 
  710: 		XTRACETIME(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
  711: 					  ISC_MSG_RUNNING,
  712: 					  "running"), now);
  713: 
  714: 		dispatch(manager, &now);
  715: 
  716: 		if (manager->nscheduled > 0) {
  717: 			XTRACETIME2(isc_msgcat_get(isc_msgcat,
  718: 						   ISC_MSGSET_GENERAL,
  719: 						   ISC_MSG_WAITUNTIL,
  720: 						   "waituntil"),
  721: 				    manager->due, now);
  722: 			result = WAITUNTIL(&manager->wakeup, &manager->lock, &manager->due);
  723: 			INSIST(result == ISC_R_SUCCESS ||
  724: 			       result == ISC_R_TIMEDOUT);
  725: 		} else {
  726: 			XTRACETIME(isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
  727: 						  ISC_MSG_WAIT, "wait"), now);
  728: 			WAIT(&manager->wakeup, &manager->lock);
  729: 		}
  730: 		XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
  731: 				      ISC_MSG_WAKEUP, "wakeup"));
  732: 	}
  733: 	UNLOCK(&manager->lock);
  734: 
  735: 	return ((isc_threadresult_t)0);
  736: }
  737: #endif /* ISC_PLATFORM_USETHREADS */
  738: 
  739: static isc_boolean_t
  740: sooner(void *v1, void *v2) {
  741: 	isc_timer_t *t1, *t2;
  742: 
  743: 	t1 = v1;
  744: 	t2 = v2;
  745: 	REQUIRE(VALID_TIMER(t1));
  746: 	REQUIRE(VALID_TIMER(t2));
  747: 
  748: 	if (isc_time_compare(&t1->due, &t2->due) < 0)
  749: 		return (ISC_TRUE);
  750: 	return (ISC_FALSE);
  751: }
  752: 
  753: static void
  754: set_index(void *what, unsigned int index) {
  755: 	isc_timer_t *timer;
  756: 
  757: 	timer = what;
  758: 	REQUIRE(VALID_TIMER(timer));
  759: 
  760: 	timer->index = index;
  761: }
  762: 
  763: isc_result_t
  764: isc_timermgr_create(isc_mem_t *mctx, isc_timermgr_t **managerp) {
  765: 	isc_timermgr_t *manager;
  766: 	isc_result_t result;
  767: 
  768: 	/*
  769: 	 * Create a timer manager.
  770: 	 */
  771: 
  772: 	REQUIRE(managerp != NULL && *managerp == NULL);
  773: 
  774: #ifndef ISC_PLATFORM_USETHREADS
  775: 	if (timermgr != NULL) {
  776: 		timermgr->refs++;
  777: 		*managerp = timermgr;
  778: 		return (ISC_R_SUCCESS);
  779: 	}
  780: #endif /* ISC_PLATFORM_USETHREADS */
  781: 
  782: 	manager = isc_mem_get(mctx, sizeof(*manager));
  783: 	if (manager == NULL)
  784: 		return (ISC_R_NOMEMORY);
  785: 
  786: 	manager->magic = TIMER_MANAGER_MAGIC;
  787: 	manager->mctx = NULL;
  788: 	manager->done = ISC_FALSE;
  789: 	INIT_LIST(manager->timers);
  790: 	manager->nscheduled = 0;
  791: 	isc_time_settoepoch(&manager->due);
  792: 	manager->heap = NULL;
  793: 	result = isc_heap_create(mctx, sooner, set_index, 0, &manager->heap);
  794: 	if (result != ISC_R_SUCCESS) {
  795: 		INSIST(result == ISC_R_NOMEMORY);
  796: 		isc_mem_put(mctx, manager, sizeof(*manager));
  797: 		return (ISC_R_NOMEMORY);
  798: 	}
  799: 	result = isc_mutex_init(&manager->lock);
  800: 	if (result != ISC_R_SUCCESS) {
  801: 		isc_heap_destroy(&manager->heap);
  802: 		isc_mem_put(mctx, manager, sizeof(*manager));
  803: 		return (result);
  804: 	}
  805: 	isc_mem_attach(mctx, &manager->mctx);
  806: #ifdef ISC_PLATFORM_USETHREADS
  807: 	if (isc_condition_init(&manager->wakeup) != ISC_R_SUCCESS) {
  808: 		isc_mem_detach(&manager->mctx);
  809: 		DESTROYLOCK(&manager->lock);
  810: 		isc_heap_destroy(&manager->heap);
  811: 		isc_mem_put(mctx, manager, sizeof(*manager));
  812: 		UNEXPECTED_ERROR(__FILE__, __LINE__,
  813: 				 "isc_condition_init() %s",
  814: 				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
  815: 						ISC_MSG_FAILED, "failed"));
  816: 		return (ISC_R_UNEXPECTED);
  817: 	}
  818: 	if (isc_thread_create(run, manager, &manager->thread) !=
  819: 	    ISC_R_SUCCESS) {
  820: 		isc_mem_detach(&manager->mctx);
  821: 		(void)isc_condition_destroy(&manager->wakeup);
  822: 		DESTROYLOCK(&manager->lock);
  823: 		isc_heap_destroy(&manager->heap);
  824: 		isc_mem_put(mctx, manager, sizeof(*manager));
  825: 		UNEXPECTED_ERROR(__FILE__, __LINE__,
  826: 				 "isc_thread_create() %s",
  827: 				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
  828: 						ISC_MSG_FAILED, "failed"));
  829: 		return (ISC_R_UNEXPECTED);
  830: 	}
  831: #else /* ISC_PLATFORM_USETHREADS */
  832: 	manager->refs = 1;
  833: 	timermgr = manager;
  834: #endif /* ISC_PLATFORM_USETHREADS */
  835: 
  836: 	*managerp = manager;
  837: 
  838: 	return (ISC_R_SUCCESS);
  839: }
  840: 
  841: void
  842: isc_timermgr_poke(isc_timermgr_t *manager) {
  843: #ifdef ISC_PLATFORM_USETHREADS
  844: 	REQUIRE(VALID_MANAGER(manager));
  845: 
  846: 	SIGNAL(&manager->wakeup);
  847: #else
  848: 	UNUSED(manager);
  849: #endif
  850: }
  851: 
  852: void
  853: isc_timermgr_destroy(isc_timermgr_t **managerp) {
  854: 	isc_timermgr_t *manager;
  855: 	isc_mem_t *mctx;
  856: 
  857: 	/*
  858: 	 * Destroy a timer manager.
  859: 	 */
  860: 
  861: 	REQUIRE(managerp != NULL);
  862: 	manager = *managerp;
  863: 	REQUIRE(VALID_MANAGER(manager));
  864: 
  865: 	LOCK(&manager->lock);
  866: 
  867: #ifndef ISC_PLATFORM_USETHREADS
  868: 	if (manager->refs > 1) {
  869: 		manager->refs--;
  870: 		UNLOCK(&manager->lock);
  871: 		*managerp = NULL;
  872: 		return;
  873: 	}
  874: 
  875: 	isc__timermgr_dispatch();
  876: #endif /* ISC_PLATFORM_USETHREADS */
  877: 
  878: 	REQUIRE(EMPTY(manager->timers));
  879: 	manager->done = ISC_TRUE;
  880: 
  881: #ifdef ISC_PLATFORM_USETHREADS
  882: 	XTRACE(isc_msgcat_get(isc_msgcat, ISC_MSGSET_TIMER,
  883: 			      ISC_MSG_SIGNALDESTROY, "signal (destroy)"));
  884: 	SIGNAL(&manager->wakeup);
  885: #endif /* ISC_PLATFORM_USETHREADS */
  886: 
  887: 	UNLOCK(&manager->lock);
  888: 
  889: #ifdef ISC_PLATFORM_USETHREADS
  890: 	/*
  891: 	 * Wait for thread to exit.
  892: 	 */
  893: 	if (isc_thread_join(manager->thread, NULL) != ISC_R_SUCCESS)
  894: 		UNEXPECTED_ERROR(__FILE__, __LINE__,
  895: 				 "isc_thread_join() %s",
  896: 				 isc_msgcat_get(isc_msgcat, ISC_MSGSET_GENERAL,
  897: 						ISC_MSG_FAILED, "failed"));
  898: #endif /* ISC_PLATFORM_USETHREADS */
  899: 
  900: 	/*
  901: 	 * Clean up.
  902: 	 */
  903: #ifdef ISC_PLATFORM_USETHREADS
  904: 	(void)isc_condition_destroy(&manager->wakeup);
  905: #endif /* ISC_PLATFORM_USETHREADS */
  906: 	DESTROYLOCK(&manager->lock);
  907: 	isc_heap_destroy(&manager->heap);
  908: 	manager->magic = 0;
  909: 	mctx = manager->mctx;
  910: 	isc_mem_put(mctx, manager, sizeof(*manager));
  911: 	isc_mem_detach(&mctx);
  912: 
  913: 	*managerp = NULL;
  914: }
  915: 
  916: #ifndef ISC_PLATFORM_USETHREADS
  917: isc_result_t
  918: isc__timermgr_nextevent(isc_time_t *when) {
  919: 	if (timermgr == NULL || timermgr->nscheduled == 0)
  920: 		return (ISC_R_NOTFOUND);
  921: 	*when = timermgr->due;
  922: 	return (ISC_R_SUCCESS);
  923: }
  924: 
  925: void
  926: isc__timermgr_dispatch(void) {
  927: 	isc_time_t now;
  928: 	if (timermgr == NULL)
  929: 		return;
  930: 	TIME_NOW(&now);
  931: 	dispatch(timermgr, &now);
  932: }
  933: #endif /* ISC_PLATFORM_USETHREADS */

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