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