1 /* $NetBSD: timer.h,v 1.6 2020/05/25 20:47:21 christos Exp $ */ 2 3 /* 4 * Copyright (C) 2004-2009 Internet Systems Consortium, Inc. ("ISC") 5 * Copyright (C) 1998-2002 Internet Software Consortium. 6 * 7 * Permission to use, copy, modify, and/or distribute this software for any 8 * purpose with or without fee is hereby granted, provided that the above 9 * copyright notice and this permission notice appear in all copies. 10 * 11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 13 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 17 * PERFORMANCE OF THIS SOFTWARE. 18 */ 19 20 /* Id: timer.h,v 1.43 2009/09/02 23:48:03 tbox Exp */ 21 22 #ifndef ISC_TIMER_H 23 #define ISC_TIMER_H 1 24 25 /***** 26 ***** Module Info 27 *****/ 28 29 /*! \file isc/timer.h 30 * \brief Provides timers which are event sources in the task system. 31 * 32 * Three types of timers are supported: 33 * 34 *\li 'ticker' timers generate a periodic tick event. 35 * 36 *\li 'once' timers generate an idle timeout event if they are idle for too 37 * long, and generate a life timeout event if their lifetime expires. 38 * They are used to implement both (possibly expiring) idle timers and 39 * 'one-shot' timers. 40 * 41 *\li 'limited' timers generate a periodic tick event until they reach 42 * their lifetime when they generate a life timeout event. 43 * 44 *\li 'inactive' timers generate no events. 45 * 46 * Timers can change type. It is typical to create a timer as 47 * an 'inactive' timer and then change it into a 'ticker' or 48 * 'once' timer. 49 * 50 *\li MP: 51 * The module ensures appropriate synchronization of data structures it 52 * creates and manipulates. 53 * Clients of this module must not be holding a timer's task's lock when 54 * making a call that affects that timer. Failure to follow this rule 55 * can result in deadlock. 56 * The caller must ensure that isc_timermgr_destroy() is called only 57 * once for a given manager. 58 * 59 * \li Reliability: 60 * No anticipated impact. 61 * 62 * \li Resources: 63 * TBS 64 * 65 * \li Security: 66 * No anticipated impact. 67 * 68 * \li Standards: 69 * None. 70 */ 71 72 73 /*** 74 *** Imports 75 ***/ 76 77 #include <isc/types.h> 78 #include <isc/event.h> 79 #include <isc/eventclass.h> 80 #include <isc/lang.h> 81 #include <isc/time.h> 82 83 ISC_LANG_BEGINDECLS 84 85 /*** 86 *** Types 87 ***/ 88 89 /*% Timer Type */ 90 typedef enum { 91 isc_timertype_ticker = 0, /*%< Ticker */ 92 isc_timertype_once = 1, /*%< Once */ 93 isc_timertype_limited = 2, /*%< Limited */ 94 isc_timertype_inactive = 3 /*%< Inactive */ 95 } isc_timertype_t; 96 97 typedef struct isc_timerevent { 98 struct isc_event common; 99 isc_time_t due; 100 } isc_timerevent_t; 101 102 #define ISC_TIMEREVENT_FIRSTEVENT (ISC_EVENTCLASS_TIMER + 0) 103 #define ISC_TIMEREVENT_TICK (ISC_EVENTCLASS_TIMER + 1) 104 #define ISC_TIMEREVENT_IDLE (ISC_EVENTCLASS_TIMER + 2) 105 #define ISC_TIMEREVENT_LIFE (ISC_EVENTCLASS_TIMER + 3) 106 #define ISC_TIMEREVENT_LASTEVENT (ISC_EVENTCLASS_TIMER + 65535) 107 108 /*% Timer and timer manager methods */ 109 typedef struct { 110 void (*destroy)(isc_timermgr_t **managerp); 111 isc_result_t (*timercreate)(isc_timermgr_t *manager, 112 isc_timertype_t type, 113 isc_time_t *expires, 114 isc_interval_t *interval, 115 isc_task_t *task, 116 isc_taskaction_t action, 117 const void *arg, 118 isc_timer_t **timerp); 119 } isc_timermgrmethods_t; 120 121 typedef struct { 122 void (*attach)(isc_timer_t *timer, isc_timer_t **timerp); 123 void (*detach)(isc_timer_t **timerp); 124 isc_result_t (*reset)(isc_timer_t *timer, isc_timertype_t type, 125 isc_time_t *expires, isc_interval_t *interval, 126 isc_boolean_t purge); 127 isc_result_t (*touch)(isc_timer_t *timer); 128 } isc_timermethods_t; 129 130 /*% 131 * This structure is actually just the common prefix of a timer manager 132 * object implementation's version of an isc_timermgr_t. 133 * \brief 134 * Direct use of this structure by clients is forbidden. timer implementations 135 * may change the structure. 'magic' must be ISCAPI_TIMERMGR_MAGIC for any 136 * of the isc_timer_ routines to work. timer implementations must maintain 137 * all timer invariants. 138 */ 139 struct isc_timermgr { 140 unsigned int impmagic; 141 unsigned int magic; 142 isc_timermgrmethods_t *methods; 143 }; 144 145 #define ISCAPI_TIMERMGR_MAGIC ISC_MAGIC('A','t','m','g') 146 #define ISCAPI_TIMERMGR_VALID(m) ((m) != NULL && \ 147 (m)->magic == ISCAPI_TIMERMGR_MAGIC) 148 149 /*% 150 * This is the common prefix of a timer object. The same note as 151 * that for the timermgr structure applies. 152 */ 153 struct isc_timer { 154 unsigned int impmagic; 155 unsigned int magic; 156 isc_timermethods_t *methods; 157 }; 158 159 #define ISCAPI_TIMER_MAGIC ISC_MAGIC('A','t','m','r') 160 #define ISCAPI_TIMER_VALID(s) ((s) != NULL && \ 161 (s)->magic == ISCAPI_TIMER_MAGIC) 162 163 /*** 164 *** Timer and Timer Manager Functions 165 *** 166 *** Note: all Ensures conditions apply only if the result is success for 167 *** those functions which return an isc_result_t. 168 ***/ 169 170 isc_result_t 171 isc_timer_create(isc_timermgr_t *manager, 172 isc_timertype_t type, 173 isc_time_t *expires, 174 isc_interval_t *interval, 175 isc_task_t *task, 176 isc_taskaction_t action, 177 const void *arg, 178 isc_timer_t **timerp); 179 /*%< 180 * Create a new 'type' timer managed by 'manager'. The timers parameters 181 * are specified by 'expires' and 'interval'. Events will be posted to 182 * 'task' and when dispatched 'action' will be called with 'arg' as the 183 * arg value. The new timer is returned in 'timerp'. 184 * 185 * Notes: 186 * 187 *\li For ticker timers, the timer will generate a 'tick' event every 188 * 'interval' seconds. The value of 'expires' is ignored. 189 * 190 *\li For once timers, 'expires' specifies the time when a life timeout 191 * event should be generated. If 'expires' is 0 (the epoch), then no life 192 * timeout will be generated. 'interval' specifies how long the timer 193 * can be idle before it generates an idle timeout. If 0, then no 194 * idle timeout will be generated. 195 * 196 *\li If 'expires' is NULL, the epoch will be used. 197 * 198 * If 'interval' is NULL, the zero interval will be used. 199 * 200 * Requires: 201 * 202 *\li 'manager' is a valid manager 203 * 204 *\li 'task' is a valid task 205 * 206 *\li 'action' is a valid action 207 * 208 *\li 'expires' points to a valid time, or is NULL. 209 * 210 *\li 'interval' points to a valid interval, or is NULL. 211 * 212 *\li type == isc_timertype_inactive || 213 * ('expires' and 'interval' are not both 0) 214 * 215 *\li 'timerp' is a valid pointer, and *timerp == NULL 216 * 217 * Ensures: 218 * 219 *\li '*timerp' is attached to the newly created timer 220 * 221 *\li The timer is attached to the task 222 * 223 *\li An idle timeout will not be generated until at least Now + the 224 * timer's interval if 'timer' is a once timer with a non-zero 225 * interval. 226 * 227 * Returns: 228 * 229 *\li Success 230 *\li No memory 231 *\li Unexpected error 232 */ 233 234 isc_result_t 235 isc_timer_reset(isc_timer_t *timer, 236 isc_timertype_t type, 237 isc_time_t *expires, 238 isc_interval_t *interval, 239 isc_boolean_t purge); 240 /*%< 241 * Change the timer's type, expires, and interval values to the given 242 * values. If 'purge' is TRUE, any pending events from this timer 243 * are purged from its task's event queue. 244 * 245 * Notes: 246 * 247 *\li If 'expires' is NULL, the epoch will be used. 248 * 249 *\li If 'interval' is NULL, the zero interval will be used. 250 * 251 * Requires: 252 * 253 *\li 'timer' is a valid timer 254 * 255 *\li The same requirements that isc_timer_create() imposes on 'type', 256 * 'expires' and 'interval' apply. 257 * 258 * Ensures: 259 * 260 *\li An idle timeout will not be generated until at least Now + the 261 * timer's interval if 'timer' is a once timer with a non-zero 262 * interval. 263 * 264 * Returns: 265 * 266 *\li Success 267 *\li No memory 268 *\li Unexpected error 269 */ 270 271 isc_result_t 272 isc_timer_touch(isc_timer_t *timer); 273 /*%< 274 * Set the last-touched time of 'timer' to the current time. 275 * 276 * Requires: 277 * 278 *\li 'timer' is a valid once timer. 279 * 280 * Ensures: 281 * 282 *\li An idle timeout will not be generated until at least Now + the 283 * timer's interval if 'timer' is a once timer with a non-zero 284 * interval. 285 * 286 * Returns: 287 * 288 *\li Success 289 *\li Unexpected error 290 */ 291 292 void 293 isc_timer_attach(isc_timer_t *timer, isc_timer_t **timerp); 294 /*%< 295 * Attach *timerp to timer. 296 * 297 * Requires: 298 * 299 *\li 'timer' is a valid timer. 300 * 301 *\li 'timerp' points to a NULL timer. 302 * 303 * Ensures: 304 * 305 *\li *timerp is attached to timer. 306 */ 307 308 void 309 isc_timer_detach(isc_timer_t **timerp); 310 /*%< 311 * Detach *timerp from its timer. 312 * 313 * Requires: 314 * 315 *\li 'timerp' points to a valid timer. 316 * 317 * Ensures: 318 * 319 *\li *timerp is NULL. 320 * 321 *\li If '*timerp' is the last reference to the timer, 322 * then: 323 * 324 *\code 325 * The timer will be shutdown 326 * 327 * The timer will detach from its task 328 * 329 * All resources used by the timer have been freed 330 * 331 * Any events already posted by the timer will be purged. 332 * Therefore, if isc_timer_detach() is called in the context 333 * of the timer's task, it is guaranteed that no more 334 * timer event callbacks will run after the call. 335 *\endcode 336 */ 337 338 isc_timertype_t 339 isc_timer_gettype(isc_timer_t *timer); 340 /*%< 341 * Return the timer type. 342 * 343 * Requires: 344 * 345 *\li 'timer' to be a valid timer. 346 */ 347 348 isc_result_t 349 isc_timermgr_createinctx(isc_mem_t *mctx, isc_appctx_t *actx, 350 isc_timermgr_t **managerp); 351 352 isc_result_t 353 isc_timermgr_create(isc_mem_t *mctx, isc_timermgr_t **managerp); 354 /*%< 355 * Create a timer manager. isc_timermgr_createinctx() also associates 356 * the new manager with the specified application context. 357 * 358 * Notes: 359 * 360 *\li All memory will be allocated in memory context 'mctx'. 361 * 362 * Requires: 363 * 364 *\li 'mctx' is a valid memory context. 365 * 366 *\li 'managerp' points to a NULL isc_timermgr_t. 367 * 368 *\li 'actx' is a valid application context (for createinctx()). 369 * 370 * Ensures: 371 * 372 *\li '*managerp' is a valid isc_timermgr_t. 373 * 374 * Returns: 375 * 376 *\li Success 377 *\li No memory 378 *\li Unexpected error 379 */ 380 381 void 382 isc_timermgr_destroy(isc_timermgr_t **managerp); 383 /*%< 384 * Destroy a timer manager. 385 * 386 * Notes: 387 * 388 *\li This routine blocks until there are no timers left in the manager, 389 * so if the caller holds any timer references using the manager, it 390 * must detach them before calling isc_timermgr_destroy() or it will 391 * block forever. 392 * 393 * Requires: 394 * 395 *\li '*managerp' is a valid isc_timermgr_t. 396 * 397 * Ensures: 398 * 399 *\li *managerp == NULL 400 * 401 *\li All resources used by the manager have been freed. 402 */ 403 404 void isc_timermgr_poke(isc_timermgr_t *m); 405 406 #ifdef USE_TIMERIMPREGISTER 407 /*%< 408 * See isc_timermgr_create() above. 409 */ 410 typedef isc_result_t 411 (*isc_timermgrcreatefunc_t)(isc_mem_t *mctx, isc_timermgr_t **managerp); 412 413 isc_result_t 414 isc__timer_register(void); 415 /*%< 416 * Register a new timer management implementation and add it to the list of 417 * supported implementations. This function must be called when a different 418 * event library is used than the one contained in the ISC library. 419 */ 420 421 isc_result_t 422 isc_timer_register(isc_timermgrcreatefunc_t createfunc); 423 /*%< 424 * A short cut function that specifies the timer management module in the ISC 425 * library for isc_timer_register(). An application that uses the ISC library 426 * usually do not have to care about this function: it would call 427 * isc_lib_register(), which internally calls this function. 428 */ 429 #endif /* USE_TIMERIMPREGISTER */ 430 431 ISC_LANG_ENDDECLS 432 433 #endif /* ISC_TIMER_H */ 434