diff options
Diffstat (limited to 'lib/isc/include/isc/timer.h')
| -rw-r--r-- | lib/isc/include/isc/timer.h | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/lib/isc/include/isc/timer.h b/lib/isc/include/isc/timer.h new file mode 100644 index 0000000..a4b2df7 --- /dev/null +++ b/lib/isc/include/isc/timer.h @@ -0,0 +1,344 @@ +/* + * Copyright (C) 2004-2008 Internet Systems Consortium, Inc. ("ISC") + * Copyright (C) 1998-2002 Internet Software Consortium. + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH + * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY + * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, + * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM + * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE + * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR + * PERFORMANCE OF THIS SOFTWARE. + */ + +/* $Id: timer.h,v 1.40 2008/06/23 23:47:11 tbox Exp $ */ + +#ifndef ISC_TIMER_H +#define ISC_TIMER_H 1 + +/***** + ***** Module Info + *****/ + +/*! \file isc/timer.h + * \brief Provides timers which are event sources in the task system. + * + * Three types of timers are supported: + * + *\li 'ticker' timers generate a periodic tick event. + * + *\li 'once' timers generate an idle timeout event if they are idle for too + * long, and generate a life timeout event if their lifetime expires. + * They are used to implement both (possibly expiring) idle timers and + * 'one-shot' timers. + * + *\li 'limited' timers generate a periodic tick event until they reach + * their lifetime when they generate a life timeout event. + * + *\li 'inactive' timers generate no events. + * + * Timers can change type. It is typical to create a timer as + * an 'inactive' timer and then change it into a 'ticker' or + * 'once' timer. + * + *\li MP: + * The module ensures appropriate synchronization of data structures it + * creates and manipulates. + * Clients of this module must not be holding a timer's task's lock when + * making a call that affects that timer. Failure to follow this rule + * can result in deadlock. + * The caller must ensure that isc_timermgr_destroy() is called only + * once for a given manager. + * + * \li Reliability: + * No anticipated impact. + * + * \li Resources: + * TBS + * + * \li Security: + * No anticipated impact. + * + * \li Standards: + * None. + */ + + +/*** + *** Imports + ***/ + +#include <isc/types.h> +#include <isc/event.h> +#include <isc/eventclass.h> +#include <isc/lang.h> +#include <isc/time.h> + +ISC_LANG_BEGINDECLS + +/*** + *** Types + ***/ + +/*% Timer Type */ +typedef enum { + isc_timertype_ticker = 0, /*%< Ticker */ + isc_timertype_once = 1, /*%< Once */ + isc_timertype_limited = 2, /*%< Limited */ + isc_timertype_inactive = 3 /*%< Inactive */ +} isc_timertype_t; + +typedef struct isc_timerevent { + struct isc_event common; + isc_time_t due; +} isc_timerevent_t; + +#define ISC_TIMEREVENT_FIRSTEVENT (ISC_EVENTCLASS_TIMER + 0) +#define ISC_TIMEREVENT_TICK (ISC_EVENTCLASS_TIMER + 1) +#define ISC_TIMEREVENT_IDLE (ISC_EVENTCLASS_TIMER + 2) +#define ISC_TIMEREVENT_LIFE (ISC_EVENTCLASS_TIMER + 3) +#define ISC_TIMEREVENT_LASTEVENT (ISC_EVENTCLASS_TIMER + 65535) + +/*** + *** Timer and Timer Manager Functions + *** + *** Note: all Ensures conditions apply only if the result is success for + *** those functions which return an isc_result_t. + ***/ + +isc_result_t +isc_timer_create(isc_timermgr_t *manager, + isc_timertype_t type, + isc_time_t *expires, + isc_interval_t *interval, + isc_task_t *task, + isc_taskaction_t action, + const void *arg, + isc_timer_t **timerp); +/*%< + * Create a new 'type' timer managed by 'manager'. The timers parameters + * are specified by 'expires' and 'interval'. Events will be posted to + * 'task' and when dispatched 'action' will be called with 'arg' as the + * arg value. The new timer is returned in 'timerp'. + * + * Notes: + * + *\li For ticker timers, the timer will generate a 'tick' event every + * 'interval' seconds. The value of 'expires' is ignored. + * + *\li For once timers, 'expires' specifies the time when a life timeout + * event should be generated. If 'expires' is 0 (the epoch), then no life + * timeout will be generated. 'interval' specifies how long the timer + * can be idle before it generates an idle timeout. If 0, then no + * idle timeout will be generated. + * + *\li If 'expires' is NULL, the epoch will be used. + * + * If 'interval' is NULL, the zero interval will be used. + * + * Requires: + * + *\li 'manager' is a valid manager + * + *\li 'task' is a valid task + * + *\li 'action' is a valid action + * + *\li 'expires' points to a valid time, or is NULL. + * + *\li 'interval' points to a valid interval, or is NULL. + * + *\li type == isc_timertype_inactive || + * ('expires' and 'interval' are not both 0) + * + *\li 'timerp' is a valid pointer, and *timerp == NULL + * + * Ensures: + * + *\li '*timerp' is attached to the newly created timer + * + *\li The timer is attached to the task + * + *\li An idle timeout will not be generated until at least Now + the + * timer's interval if 'timer' is a once timer with a non-zero + * interval. + * + * Returns: + * + *\li Success + *\li No memory + *\li Unexpected error + */ + +isc_result_t +isc_timer_reset(isc_timer_t *timer, + isc_timertype_t type, + isc_time_t *expires, + isc_interval_t *interval, + isc_boolean_t purge); +/*%< + * Change the timer's type, expires, and interval values to the given + * values. If 'purge' is TRUE, any pending events from this timer + * are purged from its task's event queue. + * + * Notes: + * + *\li If 'expires' is NULL, the epoch will be used. + * + *\li If 'interval' is NULL, the zero interval will be used. + * + * Requires: + * + *\li 'timer' is a valid timer + * + *\li The same requirements that isc_timer_create() imposes on 'type', + * 'expires' and 'interval' apply. + * + * Ensures: + * + *\li An idle timeout will not be generated until at least Now + the + * timer's interval if 'timer' is a once timer with a non-zero + * interval. + * + * Returns: + * + *\li Success + *\li No memory + *\li Unexpected error + */ + +isc_result_t +isc_timer_touch(isc_timer_t *timer); +/*%< + * Set the last-touched time of 'timer' to the current time. + * + * Requires: + * + *\li 'timer' is a valid once timer. + * + * Ensures: + * + *\li An idle timeout will not be generated until at least Now + the + * timer's interval if 'timer' is a once timer with a non-zero + * interval. + * + * Returns: + * + *\li Success + *\li Unexpected error + */ + +void +isc_timer_attach(isc_timer_t *timer, isc_timer_t **timerp); +/*%< + * Attach *timerp to timer. + * + * Requires: + * + *\li 'timer' is a valid timer. + * + *\li 'timerp' points to a NULL timer. + * + * Ensures: + * + *\li *timerp is attached to timer. + */ + +void +isc_timer_detach(isc_timer_t **timerp); +/*%< + * Detach *timerp from its timer. + * + * Requires: + * + *\li 'timerp' points to a valid timer. + * + * Ensures: + * + *\li *timerp is NULL. + * + *\li If '*timerp' is the last reference to the timer, + * then: + * + *\code + * The timer will be shutdown + * + * The timer will detach from its task + * + * All resources used by the timer have been freed + * + * Any events already posted by the timer will be purged. + * Therefore, if isc_timer_detach() is called in the context + * of the timer's task, it is guaranteed that no more + * timer event callbacks will run after the call. + *\endcode + */ + +isc_timertype_t +isc_timer_gettype(isc_timer_t *timer); +/*%< + * Return the timer type. + * + * Requires: + * + *\li 'timer' to be a valid timer. + */ + +isc_result_t +isc_timermgr_create(isc_mem_t *mctx, isc_timermgr_t **managerp); +/*%< + * Create a timer manager. + * + * Notes: + * + *\li All memory will be allocated in memory context 'mctx'. + * + * Requires: + * + *\li 'mctx' is a valid memory context. + * + *\li 'managerp' points to a NULL isc_timermgr_t. + * + * Ensures: + * + *\li '*managerp' is a valid isc_timermgr_t. + * + * Returns: + * + *\li Success + *\li No memory + *\li Unexpected error + */ + +void +isc_timermgr_destroy(isc_timermgr_t **managerp); +/*%< + * Destroy a timer manager. + * + * Notes: + * + *\li This routine blocks until there are no timers left in the manager, + * so if the caller holds any timer references using the manager, it + * must detach them before calling isc_timermgr_destroy() or it will + * block forever. + * + * Requires: + * + *\li '*managerp' is a valid isc_timermgr_t. + * + * Ensures: + * + *\li *managerp == NULL + * + *\li All resources used by the manager have been freed. + */ + +void isc_timermgr_poke(isc_timermgr_t *m); + +ISC_LANG_ENDDECLS + +#endif /* ISC_TIMER_H */ |