1 /* $NetBSD: event-internal.h,v 1.2 2013/04/11 16:56:41 christos Exp $ */ 2 /* 3 * Copyright (c) 2000-2007 Niels Provos <provos@citi.umich.edu> 4 * Copyright (c) 2007-2012 Niels Provos and Nick Mathewson 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. The name of the author may not be used to endorse or promote products 15 * derived from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 #ifndef _EVENT_INTERNAL_H_ 29 #define _EVENT_INTERNAL_H_ 30 31 #ifdef __cplusplus 32 extern "C" { 33 #endif 34 35 #include "event2/event-config.h" 36 #include <time.h> 37 #include <sys/queue.h> 38 #include "event2/event_struct.h" 39 #include "minheap-internal.h" 40 #include "evsignal-internal.h" 41 #include "mm-internal.h" 42 #include "defer-internal.h" 43 44 /* map union members back */ 45 46 /* mutually exclusive */ 47 #define ev_signal_next _ev.ev_signal.ev_signal_next 48 #define ev_io_next _ev.ev_io.ev_io_next 49 #define ev_io_timeout _ev.ev_io.ev_timeout 50 51 /* used only by signals */ 52 #define ev_ncalls _ev.ev_signal.ev_ncalls 53 #define ev_pncalls _ev.ev_signal.ev_pncalls 54 55 /* Possible values for ev_closure in struct event. */ 56 #define EV_CLOSURE_NONE 0 57 #define EV_CLOSURE_SIGNAL 1 58 #define EV_CLOSURE_PERSIST 2 59 60 /** Structure to define the backend of a given event_base. */ 61 struct eventop { 62 /** The name of this backend. */ 63 const char *name; 64 /** Function to set up an event_base to use this backend. It should 65 * create a new structure holding whatever information is needed to 66 * run the backend, and return it. The returned pointer will get 67 * stored by event_init into the event_base.evbase field. On failure, 68 * this function should return NULL. */ 69 void *(*init)(struct event_base *); 70 /** Enable reading/writing on a given fd or signal. 'events' will be 71 * the events that we're trying to enable: one or more of EV_READ, 72 * EV_WRITE, EV_SIGNAL, and EV_ET. 'old' will be those events that 73 * were enabled on this fd previously. 'fdinfo' will be a structure 74 * associated with the fd by the evmap; its size is defined by the 75 * fdinfo field below. It will be set to 0 the first time the fd is 76 * added. The function should return 0 on success and -1 on error. 77 */ 78 int (*add)(struct event_base *, evutil_socket_t fd, short old, short events, void *fdinfo); 79 /** As "add", except 'events' contains the events we mean to disable. */ 80 int (*del)(struct event_base *, evutil_socket_t fd, short old, short events, void *fdinfo); 81 /** Function to implement the core of an event loop. It must see which 82 added events are ready, and cause event_active to be called for each 83 active event (usually via event_io_active or such). It should 84 return 0 on success and -1 on error. 85 */ 86 int (*dispatch)(struct event_base *, struct timeval *); 87 /** Function to clean up and free our data from the event_base. */ 88 void (*dealloc)(struct event_base *); 89 /** Flag: set if we need to reinitialize the event base after we fork. 90 */ 91 int need_reinit; 92 /** Bit-array of supported event_method_features that this backend can 93 * provide. */ 94 enum event_method_feature features; 95 /** Length of the extra information we should record for each fd that 96 has one or more active events. This information is recorded 97 as part of the evmap entry for each fd, and passed as an argument 98 to the add and del functions above. 99 */ 100 size_t fdinfo_len; 101 }; 102 103 #ifdef WIN32 104 /* If we're on win32, then file descriptors are not nice low densely packed 105 integers. Instead, they are pointer-like windows handles, and we want to 106 use a hashtable instead of an array to map fds to events. 107 */ 108 #define EVMAP_USE_HT 109 #endif 110 111 /* #define HT_CACHE_HASH_VALS */ 112 113 #ifdef EVMAP_USE_HT 114 #include "ht-internal.h" 115 struct event_map_entry; 116 HT_HEAD(event_io_map, event_map_entry); 117 #else 118 #define event_io_map event_signal_map 119 #endif 120 121 /* Used to map signal numbers to a list of events. If EVMAP_USE_HT is not 122 defined, this structure is also used as event_io_map, which maps fds to a 123 list of events. 124 */ 125 struct event_signal_map { 126 /* An array of evmap_io * or of evmap_signal *; empty entries are 127 * set to NULL. */ 128 void **entries; 129 /* The number of entries available in entries */ 130 int nentries; 131 }; 132 133 /* A list of events waiting on a given 'common' timeout value. Ordinarily, 134 * events waiting for a timeout wait on a minheap. Sometimes, however, a 135 * queue can be faster. 136 **/ 137 struct common_timeout_list { 138 /* List of events currently waiting in the queue. */ 139 struct event_list events; 140 /* 'magic' timeval used to indicate the duration of events in this 141 * queue. */ 142 struct timeval duration; 143 /* Event that triggers whenever one of the events in the queue is 144 * ready to activate */ 145 struct event timeout_event; 146 /* The event_base that this timeout list is part of */ 147 struct event_base *base; 148 }; 149 150 /** Mask used to get the real tv_usec value from a common timeout. */ 151 #define COMMON_TIMEOUT_MICROSECONDS_MASK 0x000fffff 152 153 struct event_change; 154 155 /* List of 'changes' since the last call to eventop.dispatch. Only maintained 156 * if the backend is using changesets. */ 157 struct event_changelist { 158 struct event_change *changes; 159 int n_changes; 160 int changes_size; 161 }; 162 163 #ifndef _EVENT_DISABLE_DEBUG_MODE 164 /* Global internal flag: set to one if debug mode is on. */ 165 extern int _event_debug_mode_on; 166 #define EVENT_DEBUG_MODE_IS_ON() (_event_debug_mode_on) 167 #else 168 #define EVENT_DEBUG_MODE_IS_ON() (0) 169 #endif 170 171 struct event_base { 172 /** Function pointers and other data to describe this event_base's 173 * backend. */ 174 const struct eventop *evsel; 175 /** Pointer to backend-specific data. */ 176 void *evbase; 177 178 /** List of changes to tell backend about at next dispatch. Only used 179 * by the O(1) backends. */ 180 struct event_changelist changelist; 181 182 /** Function pointers used to describe the backend that this event_base 183 * uses for signals */ 184 const struct eventop *evsigsel; 185 /** Data to implement the common signal handelr code. */ 186 struct evsig_info sig; 187 188 /** Number of virtual events */ 189 int virtual_event_count; 190 /** Number of total events added to this event_base */ 191 int event_count; 192 /** Number of total events active in this event_base */ 193 int event_count_active; 194 195 /** Set if we should terminate the loop once we're done processing 196 * events. */ 197 int event_gotterm; 198 /** Set if we should terminate the loop immediately */ 199 int event_break; 200 /** Set if we should start a new instance of the loop immediately. */ 201 int event_continue; 202 203 /** The currently running priority of events */ 204 int event_running_priority; 205 206 /** Set if we're running the event_base_loop function, to prevent 207 * reentrant invocation. */ 208 int running_loop; 209 210 /* Active event management. */ 211 /** An array of nactivequeues queues for active events (ones that 212 * have triggered, and whose callbacks need to be called). Low 213 * priority numbers are more important, and stall higher ones. 214 */ 215 struct event_list *activequeues; 216 /** The length of the activequeues array */ 217 int nactivequeues; 218 219 /* common timeout logic */ 220 221 /** An array of common_timeout_list* for all of the common timeout 222 * values we know. */ 223 struct common_timeout_list **common_timeout_queues; 224 /** The number of entries used in common_timeout_queues */ 225 int n_common_timeouts; 226 /** The total size of common_timeout_queues. */ 227 int n_common_timeouts_allocated; 228 229 /** List of defered_cb that are active. We run these after the active 230 * events. */ 231 struct deferred_cb_queue defer_queue; 232 233 /** Mapping from file descriptors to enabled (added) events */ 234 struct event_io_map io; 235 236 /** Mapping from signal numbers to enabled (added) events. */ 237 struct event_signal_map sigmap; 238 239 /** All events that have been enabled (added) in this event_base */ 240 struct event_list eventqueue; 241 242 /** Stored timeval; used to detect when time is running backwards. */ 243 struct timeval event_tv; 244 245 /** Priority queue of events with timeouts. */ 246 struct min_heap timeheap; 247 248 /** Stored timeval: used to avoid calling gettimeofday/clock_gettime 249 * too often. */ 250 struct timeval tv_cache; 251 252 #if defined(_EVENT_HAVE_CLOCK_GETTIME) && defined(CLOCK_MONOTONIC) 253 /** Difference between internal time (maybe from clock_gettime) and 254 * gettimeofday. */ 255 struct timeval tv_clock_diff; 256 /** Second in which we last updated tv_clock_diff, in monotonic time. */ 257 time_t last_updated_clock_diff; 258 #endif 259 260 #ifndef _EVENT_DISABLE_THREAD_SUPPORT 261 /* threading support */ 262 /** The thread currently running the event_loop for this base */ 263 unsigned long th_owner_id; 264 /** A lock to prevent conflicting accesses to this event_base */ 265 void *th_base_lock; 266 /** The event whose callback is executing right now */ 267 struct event *current_event; 268 /** A condition that gets signalled when we're done processing an 269 * event with waiters on it. */ 270 void *current_event_cond; 271 /** Number of threads blocking on current_event_cond. */ 272 int current_event_waiters; 273 #endif 274 275 #ifdef WIN32 276 /** IOCP support structure, if IOCP is enabled. */ 277 struct event_iocp_port *iocp; 278 #endif 279 280 /** Flags that this base was configured with */ 281 enum event_base_config_flag flags; 282 283 /* Notify main thread to wake up break, etc. */ 284 /** True if the base already has a pending notify, and we don't need 285 * to add any more. */ 286 int is_notify_pending; 287 /** A socketpair used by some th_notify functions to wake up the main 288 * thread. */ 289 evutil_socket_t th_notify_fd[2]; 290 /** An event used by some th_notify functions to wake up the main 291 * thread. */ 292 struct event th_notify; 293 /** A function used to wake up the main thread from another thread. */ 294 int (*th_notify_fn)(struct event_base *base); 295 }; 296 297 struct event_config_entry { 298 TAILQ_ENTRY(event_config_entry) next; 299 300 const char *avoid_method; 301 }; 302 303 /** Internal structure: describes the configuration we want for an event_base 304 * that we're about to allocate. */ 305 struct event_config { 306 TAILQ_HEAD(event_configq, event_config_entry) entries; 307 308 int n_cpus_hint; 309 enum event_method_feature require_features; 310 enum event_base_config_flag flags; 311 }; 312 313 /* Internal use only: Functions that might be missing from <sys/queue.h> */ 314 #if defined(_EVENT_HAVE_SYS_QUEUE_H) && !defined(_EVENT_HAVE_TAILQFOREACH) 315 #ifndef TAILQ_FIRST 316 #define TAILQ_FIRST(head) ((head)->tqh_first) 317 #endif 318 #ifndef TAILQ_END 319 #define TAILQ_END(head) NULL 320 #endif 321 #ifndef TAILQ_NEXT 322 #define TAILQ_NEXT(elm, field) ((elm)->field.tqe_next) 323 #endif 324 325 #ifndef TAILQ_FOREACH 326 #define TAILQ_FOREACH(var, head, field) \ 327 for ((var) = TAILQ_FIRST(head); \ 328 (var) != TAILQ_END(head); \ 329 (var) = TAILQ_NEXT(var, field)) 330 #endif 331 332 #ifndef TAILQ_INSERT_BEFORE 333 #define TAILQ_INSERT_BEFORE(listelm, elm, field) do { \ 334 (elm)->field.tqe_prev = (listelm)->field.tqe_prev; \ 335 (elm)->field.tqe_next = (listelm); \ 336 *(listelm)->field.tqe_prev = (elm); \ 337 (listelm)->field.tqe_prev = &(elm)->field.tqe_next; \ 338 } while (/*CONSTCOND*/0) 339 #endif 340 #endif /* TAILQ_FOREACH */ 341 342 #define N_ACTIVE_CALLBACKS(base) \ 343 ((base)->event_count_active + (base)->defer_queue.active_count) 344 345 int _evsig_set_handler(struct event_base *base, int evsignal, 346 void (*fn)(int)); 347 int _evsig_restore_handler(struct event_base *base, int evsignal); 348 349 350 void event_active_nolock(struct event *ev, int res, short count); 351 352 /* FIXME document. */ 353 void event_base_add_virtual(struct event_base *base); 354 void event_base_del_virtual(struct event_base *base); 355 356 /** For debugging: unless assertions are disabled, verify the referential 357 integrity of the internal data structures of 'base'. This operation can 358 be expensive. 359 360 Returns on success; aborts on failure. 361 */ 362 void event_base_assert_ok(struct event_base *base); 363 364 #ifdef __cplusplus 365 } 366 #endif 367 368 #endif /* _EVENT_INTERNAL_H_ */ 369 370