forked from libevent/libevent
-
Notifications
You must be signed in to change notification settings - Fork 0
/
event.c
3782 lines (3257 loc) · 96.1 KB
/
event.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
* Copyright (c) 2000-2007 Niels Provos <[email protected]>
* Copyright (c) 2007-2012 Niels Provos and Nick Mathewson
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "event2/event-config.h"
#include "evconfig-private.h"
#ifdef _WIN32
#include <winsock2.h>
#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#undef WIN32_LEAN_AND_MEAN
#endif
#include <sys/types.h>
#if !defined(_WIN32) && defined(EVENT__HAVE_SYS_TIME_H)
#include <sys/time.h>
#endif
#include <sys/queue.h>
#ifdef EVENT__HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#ifdef EVENT__HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <time.h>
#include <limits.h>
#include "event2/event.h"
#include "event2/event_struct.h"
#include "event2/event_compat.h"
#include "event-internal.h"
#include "defer-internal.h"
#include "evthread-internal.h"
#include "event2/thread.h"
#include "event2/util.h"
#include "log-internal.h"
#include "evmap-internal.h"
#include "iocp-internal.h"
#include "changelist-internal.h"
#define HT_NO_CACHE_HASH_VALUES
#include "ht-internal.h"
#include "util-internal.h"
#ifdef EVENT__HAVE_WORKING_KQUEUE
#include "kqueue-internal.h"
#endif
#ifdef EVENT__HAVE_EVENT_PORTS
extern const struct eventop evportops;
#endif
#ifdef EVENT__HAVE_SELECT
extern const struct eventop selectops;
#endif
#ifdef EVENT__HAVE_POLL
extern const struct eventop pollops;
#endif
#ifdef EVENT__HAVE_EPOLL
extern const struct eventop epollops;
#endif
#ifdef EVENT__HAVE_WORKING_KQUEUE
extern const struct eventop kqops;
#endif
#ifdef EVENT__HAVE_DEVPOLL
extern const struct eventop devpollops;
#endif
#ifdef _WIN32
extern const struct eventop win32ops;
#endif
/* Array of backends in order of preference. */
static const struct eventop *eventops[] = {
#ifdef EVENT__HAVE_EVENT_PORTS
&evportops,
#endif
#ifdef EVENT__HAVE_WORKING_KQUEUE
&kqops,
#endif
#ifdef EVENT__HAVE_EPOLL
&epollops,
#endif
#ifdef EVENT__HAVE_DEVPOLL
&devpollops,
#endif
#ifdef EVENT__HAVE_POLL
&pollops,
#endif
#ifdef EVENT__HAVE_SELECT
&selectops,
#endif
#ifdef _WIN32
&win32ops,
#endif
NULL
};
/* Global state; deprecated */
struct event_base *event_global_current_base_ = NULL;
#define current_base event_global_current_base_
/* Global state */
static void *event_self_cbarg_ptr_ = NULL;
/* Prototypes */
static void event_queue_insert_active(struct event_base *, struct event_callback *);
static void event_queue_insert_active_later(struct event_base *, struct event_callback *);
static void event_queue_insert_timeout(struct event_base *, struct event *);
static void event_queue_insert_inserted(struct event_base *, struct event *);
static void event_queue_remove_active(struct event_base *, struct event_callback *);
static void event_queue_remove_active_later(struct event_base *, struct event_callback *);
static void event_queue_remove_timeout(struct event_base *, struct event *);
static void event_queue_remove_inserted(struct event_base *, struct event *);
static void event_queue_make_later_events_active(struct event_base *base);
static int evthread_make_base_notifiable_nolock_(struct event_base *base);
static int event_del_(struct event *ev, int blocking);
#ifdef USE_REINSERT_TIMEOUT
/* This code seems buggy; only turn it on if we find out what the trouble is. */
static void event_queue_reinsert_timeout(struct event_base *,struct event *, int was_common, int is_common, int old_timeout_idx);
#endif
static int event_haveevents(struct event_base *);
static int event_process_active(struct event_base *);
static int timeout_next(struct event_base *, struct timeval **);
static void timeout_process(struct event_base *);
static inline void event_signal_closure(struct event_base *, struct event *ev);
static inline void event_persist_closure(struct event_base *, struct event *ev);
static int evthread_notify_base(struct event_base *base);
static void insert_common_timeout_inorder(struct common_timeout_list *ctl,
struct event *ev);
#ifndef EVENT__DISABLE_DEBUG_MODE
/* These functions implement a hashtable of which 'struct event *' structures
* have been setup or added. We don't want to trust the content of the struct
* event itself, since we're trying to work through cases where an event gets
* clobbered or freed. Instead, we keep a hashtable indexed by the pointer.
*/
struct event_debug_entry {
HT_ENTRY(event_debug_entry) node;
const struct event *ptr;
unsigned added : 1;
};
static inline unsigned
hash_debug_entry(const struct event_debug_entry *e)
{
/* We need to do this silliness to convince compilers that we
* honestly mean to cast e->ptr to an integer, and discard any
* part of it that doesn't fit in an unsigned.
*/
unsigned u = (unsigned) ((ev_uintptr_t) e->ptr);
/* Our hashtable implementation is pretty sensitive to low bits,
* and every struct event is over 64 bytes in size, so we can
* just say >>6. */
return (u >> 6);
}
static inline int
eq_debug_entry(const struct event_debug_entry *a,
const struct event_debug_entry *b)
{
return a->ptr == b->ptr;
}
int event_debug_mode_on_ = 0;
/* Set if it's too late to enable event_debug_mode. */
static int event_debug_mode_too_late = 0;
#ifndef EVENT__DISABLE_THREAD_SUPPORT
static void *event_debug_map_lock_ = NULL;
#endif
static HT_HEAD(event_debug_map, event_debug_entry) global_debug_map =
HT_INITIALIZER();
HT_PROTOTYPE(event_debug_map, event_debug_entry, node, hash_debug_entry,
eq_debug_entry)
HT_GENERATE(event_debug_map, event_debug_entry, node, hash_debug_entry,
eq_debug_entry, 0.5, mm_malloc, mm_realloc, mm_free)
/* Macro: record that ev is now setup (that is, ready for an add) */
#define event_debug_note_setup_(ev) do { \
if (event_debug_mode_on_) { \
struct event_debug_entry *dent,find; \
find.ptr = (ev); \
EVLOCK_LOCK(event_debug_map_lock_, 0); \
dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
if (dent) { \
dent->added = 0; \
} else { \
dent = mm_malloc(sizeof(*dent)); \
if (!dent) \
event_err(1, \
"Out of memory in debugging code"); \
dent->ptr = (ev); \
dent->added = 0; \
HT_INSERT(event_debug_map, &global_debug_map, dent); \
} \
EVLOCK_UNLOCK(event_debug_map_lock_, 0); \
} \
event_debug_mode_too_late = 1; \
} while (0)
/* Macro: record that ev is no longer setup */
#define event_debug_note_teardown_(ev) do { \
if (event_debug_mode_on_) { \
struct event_debug_entry *dent,find; \
find.ptr = (ev); \
EVLOCK_LOCK(event_debug_map_lock_, 0); \
dent = HT_REMOVE(event_debug_map, &global_debug_map, &find); \
if (dent) \
mm_free(dent); \
EVLOCK_UNLOCK(event_debug_map_lock_, 0); \
} \
event_debug_mode_too_late = 1; \
} while (0)
/* Macro: record that ev is now added */
#define event_debug_note_add_(ev) do { \
if (event_debug_mode_on_) { \
struct event_debug_entry *dent,find; \
find.ptr = (ev); \
EVLOCK_LOCK(event_debug_map_lock_, 0); \
dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
if (dent) { \
dent->added = 1; \
} else { \
event_errx(EVENT_ERR_ABORT_, \
"%s: noting an add on a non-setup event %p" \
" (events: 0x%x, fd: "EV_SOCK_FMT \
", flags: 0x%x)", \
__func__, (ev), (ev)->ev_events, \
EV_SOCK_ARG((ev)->ev_fd), (ev)->ev_flags); \
} \
EVLOCK_UNLOCK(event_debug_map_lock_, 0); \
} \
event_debug_mode_too_late = 1; \
} while (0)
/* Macro: record that ev is no longer added */
#define event_debug_note_del_(ev) do { \
if (event_debug_mode_on_) { \
struct event_debug_entry *dent,find; \
find.ptr = (ev); \
EVLOCK_LOCK(event_debug_map_lock_, 0); \
dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
if (dent) { \
dent->added = 0; \
} else { \
event_errx(EVENT_ERR_ABORT_, \
"%s: noting a del on a non-setup event %p" \
" (events: 0x%x, fd: "EV_SOCK_FMT \
", flags: 0x%x)", \
__func__, (ev), (ev)->ev_events, \
EV_SOCK_ARG((ev)->ev_fd), (ev)->ev_flags); \
} \
EVLOCK_UNLOCK(event_debug_map_lock_, 0); \
} \
event_debug_mode_too_late = 1; \
} while (0)
/* Macro: assert that ev is setup (i.e., okay to add or inspect) */
#define event_debug_assert_is_setup_(ev) do { \
if (event_debug_mode_on_) { \
struct event_debug_entry *dent,find; \
find.ptr = (ev); \
EVLOCK_LOCK(event_debug_map_lock_, 0); \
dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
if (!dent) { \
event_errx(EVENT_ERR_ABORT_, \
"%s called on a non-initialized event %p" \
" (events: 0x%x, fd: "EV_SOCK_FMT\
", flags: 0x%x)", \
__func__, (ev), (ev)->ev_events, \
EV_SOCK_ARG((ev)->ev_fd), (ev)->ev_flags); \
} \
EVLOCK_UNLOCK(event_debug_map_lock_, 0); \
} \
} while (0)
/* Macro: assert that ev is not added (i.e., okay to tear down or set
* up again) */
#define event_debug_assert_not_added_(ev) do { \
if (event_debug_mode_on_) { \
struct event_debug_entry *dent,find; \
find.ptr = (ev); \
EVLOCK_LOCK(event_debug_map_lock_, 0); \
dent = HT_FIND(event_debug_map, &global_debug_map, &find); \
if (dent && dent->added) { \
event_errx(EVENT_ERR_ABORT_, \
"%s called on an already added event %p" \
" (events: 0x%x, fd: "EV_SOCK_FMT", " \
"flags: 0x%x)", \
__func__, (ev), (ev)->ev_events, \
EV_SOCK_ARG((ev)->ev_fd), (ev)->ev_flags); \
} \
EVLOCK_UNLOCK(event_debug_map_lock_, 0); \
} \
} while (0)
#else
#define event_debug_note_setup_(ev) \
((void)0)
#define event_debug_note_teardown_(ev) \
((void)0)
#define event_debug_note_add_(ev) \
((void)0)
#define event_debug_note_del_(ev) \
((void)0)
#define event_debug_assert_is_setup_(ev) \
((void)0)
#define event_debug_assert_not_added_(ev) \
((void)0)
#endif
#define EVENT_BASE_ASSERT_LOCKED(base) \
EVLOCK_ASSERT_LOCKED((base)->th_base_lock)
/* How often (in seconds) do we check for changes in wall clock time relative
* to monotonic time? Set this to -1 for 'never.' */
#define CLOCK_SYNC_INTERVAL 5
/** Set 'tp' to the current time according to 'base'. We must hold the lock
* on 'base'. If there is a cached time, return it. Otherwise, use
* clock_gettime or gettimeofday as appropriate to find out the right time.
* Return 0 on success, -1 on failure.
*/
static int
gettime(struct event_base *base, struct timeval *tp)
{
EVENT_BASE_ASSERT_LOCKED(base);
if (base->tv_cache.tv_sec) {
*tp = base->tv_cache;
return (0);
}
if (evutil_gettime_monotonic_(&base->monotonic_timer, tp) == -1) {
return -1;
}
if (base->last_updated_clock_diff + CLOCK_SYNC_INTERVAL
< tp->tv_sec) {
struct timeval tv;
evutil_gettimeofday(&tv,NULL);
evutil_timersub(&tv, tp, &base->tv_clock_diff);
base->last_updated_clock_diff = tp->tv_sec;
}
return 0;
}
int
event_base_gettimeofday_cached(struct event_base *base, struct timeval *tv)
{
int r;
if (!base) {
base = current_base;
if (!current_base)
return evutil_gettimeofday(tv, NULL);
}
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
if (base->tv_cache.tv_sec == 0) {
r = evutil_gettimeofday(tv, NULL);
} else {
evutil_timeradd(&base->tv_cache, &base->tv_clock_diff, tv);
r = 0;
}
EVBASE_RELEASE_LOCK(base, th_base_lock);
return r;
}
/** Make 'base' have no current cached time. */
static inline void
clear_time_cache(struct event_base *base)
{
base->tv_cache.tv_sec = 0;
}
/** Replace the cached time in 'base' with the current time. */
static inline void
update_time_cache(struct event_base *base)
{
base->tv_cache.tv_sec = 0;
if (!(base->flags & EVENT_BASE_FLAG_NO_CACHE_TIME))
gettime(base, &base->tv_cache);
}
int
event_base_update_cache_time(struct event_base *base)
{
if (!base) {
base = current_base;
if (!current_base)
return -1;
}
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
if (base->running_loop)
update_time_cache(base);
EVBASE_RELEASE_LOCK(base, th_base_lock);
return 0;
}
static inline struct event *
event_callback_to_event(struct event_callback *evcb)
{
EVUTIL_ASSERT((evcb->evcb_flags & EVLIST_INIT));
return EVUTIL_UPCAST(evcb, struct event, ev_evcallback);
}
static inline struct event_callback *
event_to_event_callback(struct event *ev)
{
return &ev->ev_evcallback;
}
struct event_base *
event_init(void)
{
struct event_base *base = event_base_new_with_config(NULL);
if (base == NULL) {
event_errx(1, "%s: Unable to construct event_base", __func__);
return NULL;
}
current_base = base;
return (base);
}
struct event_base *
event_base_new(void)
{
struct event_base *base = NULL;
struct event_config *cfg = event_config_new();
if (cfg) {
base = event_base_new_with_config(cfg);
event_config_free(cfg);
}
return base;
}
/** Return true iff 'method' is the name of a method that 'cfg' tells us to
* avoid. */
static int
event_config_is_avoided_method(const struct event_config *cfg,
const char *method)
{
struct event_config_entry *entry;
TAILQ_FOREACH(entry, &cfg->entries, next) {
if (entry->avoid_method != NULL &&
strcmp(entry->avoid_method, method) == 0)
return (1);
}
return (0);
}
/** Return true iff 'method' is disabled according to the environment. */
static int
event_is_method_disabled(const char *name)
{
char environment[64];
int i;
evutil_snprintf(environment, sizeof(environment), "EVENT_NO%s", name);
for (i = 8; environment[i] != '\0'; ++i)
environment[i] = EVUTIL_TOUPPER_(environment[i]);
/* Note that evutil_getenv_() ignores the environment entirely if
* we're setuid */
return (evutil_getenv_(environment) != NULL);
}
int
event_base_get_features(const struct event_base *base)
{
return base->evsel->features;
}
void
event_enable_debug_mode(void)
{
#ifndef EVENT__DISABLE_DEBUG_MODE
if (event_debug_mode_on_)
event_errx(1, "%s was called twice!", __func__);
if (event_debug_mode_too_late)
event_errx(1, "%s must be called *before* creating any events "
"or event_bases",__func__);
event_debug_mode_on_ = 1;
HT_INIT(event_debug_map, &global_debug_map);
#endif
}
#if 0
void
event_disable_debug_mode(void)
{
struct event_debug_entry **ent, *victim;
EVLOCK_LOCK(event_debug_map_lock_, 0);
for (ent = HT_START(event_debug_map, &global_debug_map); ent; ) {
victim = *ent;
ent = HT_NEXT_RMV(event_debug_map,&global_debug_map, ent);
mm_free(victim);
}
HT_CLEAR(event_debug_map, &global_debug_map);
EVLOCK_UNLOCK(event_debug_map_lock_ , 0);
}
#endif
struct event_base *
event_base_new_with_config(const struct event_config *cfg)
{
int i;
struct event_base *base;
int should_check_environment;
#ifndef EVENT__DISABLE_DEBUG_MODE
event_debug_mode_too_late = 1;
#endif
if ((base = mm_calloc(1, sizeof(struct event_base))) == NULL) {
event_warn("%s: calloc", __func__);
return NULL;
}
if (cfg)
base->flags = cfg->flags;
should_check_environment =
!(cfg && (cfg->flags & EVENT_BASE_FLAG_IGNORE_ENV));
{
struct timeval tmp;
int precise_time =
cfg && (cfg->flags & EVENT_BASE_FLAG_PRECISE_TIMER);
int flags;
if (should_check_environment && !precise_time) {
precise_time = evutil_getenv_("EVENT_PRECISE_TIMER") != NULL;
base->flags |= EVENT_BASE_FLAG_PRECISE_TIMER;
}
flags = precise_time ? EV_MONOT_PRECISE : 0;
evutil_configure_monotonic_time_(&base->monotonic_timer, flags);
gettime(base, &tmp);
}
min_heap_ctor_(&base->timeheap);
base->sig.ev_signal_pair[0] = -1;
base->sig.ev_signal_pair[1] = -1;
base->th_notify_fd[0] = -1;
base->th_notify_fd[1] = -1;
TAILQ_INIT(&base->active_later_queue);
evmap_io_initmap_(&base->io);
evmap_signal_initmap_(&base->sigmap);
event_changelist_init_(&base->changelist);
base->evbase = NULL;
if (cfg) {
memcpy(&base->max_dispatch_time,
&cfg->max_dispatch_interval, sizeof(struct timeval));
base->limit_callbacks_after_prio =
cfg->limit_callbacks_after_prio;
} else {
base->max_dispatch_time.tv_sec = -1;
base->limit_callbacks_after_prio = 1;
}
if (cfg && cfg->max_dispatch_callbacks >= 0) {
base->max_dispatch_callbacks = cfg->max_dispatch_callbacks;
} else {
base->max_dispatch_callbacks = INT_MAX;
}
if (base->max_dispatch_callbacks == INT_MAX &&
base->max_dispatch_time.tv_sec == -1)
base->limit_callbacks_after_prio = INT_MAX;
for (i = 0; eventops[i] && !base->evbase; i++) {
if (cfg != NULL) {
/* determine if this backend should be avoided */
if (event_config_is_avoided_method(cfg,
eventops[i]->name))
continue;
if ((eventops[i]->features & cfg->require_features)
!= cfg->require_features)
continue;
}
/* also obey the environment variables */
if (should_check_environment &&
event_is_method_disabled(eventops[i]->name))
continue;
base->evsel = eventops[i];
base->evbase = base->evsel->init(base);
}
if (base->evbase == NULL) {
event_warnx("%s: no event mechanism available",
__func__);
base->evsel = NULL;
event_base_free(base);
return NULL;
}
if (evutil_getenv_("EVENT_SHOW_METHOD"))
event_msgx("libevent using: %s", base->evsel->name);
/* allocate a single active event queue */
if (event_base_priority_init(base, 1) < 0) {
event_base_free(base);
return NULL;
}
/* prepare for threading */
#ifndef EVENT__DISABLE_THREAD_SUPPORT
if (EVTHREAD_LOCKING_ENABLED() &&
(!cfg || !(cfg->flags & EVENT_BASE_FLAG_NOLOCK))) {
int r;
EVTHREAD_ALLOC_LOCK(base->th_base_lock, 0);
EVTHREAD_ALLOC_COND(base->current_event_cond);
r = evthread_make_base_notifiable(base);
if (r<0) {
event_warnx("%s: Unable to make base notifiable.", __func__);
event_base_free(base);
return NULL;
}
}
#endif
#ifdef _WIN32
if (cfg && (cfg->flags & EVENT_BASE_FLAG_STARTUP_IOCP))
event_base_start_iocp_(base, cfg->n_cpus_hint);
#endif
return (base);
}
int
event_base_start_iocp_(struct event_base *base, int n_cpus)
{
#ifdef _WIN32
if (base->iocp)
return 0;
base->iocp = event_iocp_port_launch_(n_cpus);
if (!base->iocp) {
event_warnx("%s: Couldn't launch IOCP", __func__);
return -1;
}
return 0;
#else
return -1;
#endif
}
void
event_base_stop_iocp_(struct event_base *base)
{
#ifdef _WIN32
int rv;
if (!base->iocp)
return;
rv = event_iocp_shutdown_(base->iocp, -1);
EVUTIL_ASSERT(rv >= 0);
base->iocp = NULL;
#endif
}
static int
event_base_cancel_single_callback_(struct event_base *base,
struct event_callback *evcb,
int run_finalizers)
{
int result = 0;
if (evcb->evcb_flags & EVLIST_INIT) {
struct event *ev = event_callback_to_event(evcb);
if (!(ev->ev_flags & EVLIST_INTERNAL)) {
event_del_(ev, EVENT_DEL_EVEN_IF_FINALIZING);
result = 1;
}
} else {
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
event_callback_cancel_nolock_(base, evcb, 1);
EVBASE_RELEASE_LOCK(base, th_base_lock);
result = 1;
}
if (run_finalizers && (evcb->evcb_flags & EVLIST_FINALIZING)) {
switch (evcb->evcb_closure) {
case EV_CLOSURE_EVENT_FINALIZE:
case EV_CLOSURE_EVENT_FINALIZE_FREE: {
struct event *ev = event_callback_to_event(evcb);
ev->ev_evcallback.evcb_cb_union.evcb_evfinalize(ev, ev->ev_arg);
if (evcb->evcb_closure == EV_CLOSURE_EVENT_FINALIZE_FREE)
mm_free(ev);
break;
}
case EV_CLOSURE_CB_FINALIZE:
evcb->evcb_cb_union.evcb_cbfinalize(evcb, evcb->evcb_arg);
break;
default:
break;
}
}
return result;
}
static void
event_base_free_(struct event_base *base, int run_finalizers)
{
int i, n_deleted=0;
struct event *ev;
/* XXXX grab the lock? If there is contention when one thread frees
* the base, then the contending thread will be very sad soon. */
/* event_base_free(NULL) is how to free the current_base if we
* made it with event_init and forgot to hold a reference to it. */
if (base == NULL && current_base)
base = current_base;
/* Don't actually free NULL. */
if (base == NULL) {
event_warnx("%s: no base to free", __func__);
return;
}
/* XXX(niels) - check for internal events first */
#ifdef _WIN32
event_base_stop_iocp_(base);
#endif
/* threading fds if we have them */
if (base->th_notify_fd[0] != -1) {
event_del(&base->th_notify);
EVUTIL_CLOSESOCKET(base->th_notify_fd[0]);
if (base->th_notify_fd[1] != -1)
EVUTIL_CLOSESOCKET(base->th_notify_fd[1]);
base->th_notify_fd[0] = -1;
base->th_notify_fd[1] = -1;
event_debug_unassign(&base->th_notify);
}
/* Delete all non-internal events. */
evmap_delete_all_(base);
while ((ev = min_heap_top_(&base->timeheap)) != NULL) {
event_del(ev);
++n_deleted;
}
for (i = 0; i < base->n_common_timeouts; ++i) {
struct common_timeout_list *ctl =
base->common_timeout_queues[i];
event_del(&ctl->timeout_event); /* Internal; doesn't count */
event_debug_unassign(&ctl->timeout_event);
for (ev = TAILQ_FIRST(&ctl->events); ev; ) {
struct event *next = TAILQ_NEXT(ev,
ev_timeout_pos.ev_next_with_common_timeout);
if (!(ev->ev_flags & EVLIST_INTERNAL)) {
event_del(ev);
++n_deleted;
}
ev = next;
}
mm_free(ctl);
}
if (base->common_timeout_queues)
mm_free(base->common_timeout_queues);
for (i = 0; i < base->nactivequeues; ++i) {
struct event_callback *evcb, *next;
for (evcb = TAILQ_FIRST(&base->activequeues[i]); evcb; ) {
next = TAILQ_NEXT(evcb, evcb_active_next);
n_deleted += event_base_cancel_single_callback_(base, evcb, run_finalizers);
evcb = next;
}
}
{
struct event_callback *evcb;
while ((evcb = TAILQ_FIRST(&base->active_later_queue))) {
n_deleted += event_base_cancel_single_callback_(base, evcb, run_finalizers);
}
}
if (n_deleted)
event_debug(("%s: %d events were still set in base",
__func__, n_deleted));
while (LIST_FIRST(&base->once_events)) {
struct event_once *eonce = LIST_FIRST(&base->once_events);
LIST_REMOVE(eonce, next_once);
mm_free(eonce);
}
if (base->evsel != NULL && base->evsel->dealloc != NULL)
base->evsel->dealloc(base);
for (i = 0; i < base->nactivequeues; ++i)
EVUTIL_ASSERT(TAILQ_EMPTY(&base->activequeues[i]));
EVUTIL_ASSERT(min_heap_empty_(&base->timeheap));
min_heap_dtor_(&base->timeheap);
mm_free(base->activequeues);
evmap_io_clear_(&base->io);
evmap_signal_clear_(&base->sigmap);
event_changelist_freemem_(&base->changelist);
EVTHREAD_FREE_LOCK(base->th_base_lock, 0);
EVTHREAD_FREE_COND(base->current_event_cond);
/* If we're freeing current_base, there won't be a current_base. */
if (base == current_base)
current_base = NULL;
mm_free(base);
}
void
event_base_free_nofinalize(struct event_base *base)
{
event_base_free_(base, 0);
}
void
event_base_free(struct event_base *base)
{
event_base_free_(base, 1);
}
/* Fake eventop; used to disable the backend temporarily inside event_reinit
* so that we can call event_del() on an event without telling the backend.
*/
static int
nil_backend_del(struct event_base *b, evutil_socket_t fd, short old,
short events, void *fdinfo)
{
return 0;
}
const struct eventop nil_eventop = {
"nil",
NULL, /* init: unused. */
NULL, /* add: unused. */
nil_backend_del, /* del: used, so needs to be killed. */
NULL, /* dispatch: unused. */
NULL, /* dealloc: unused. */
0, 0, 0
};
/* reinitialize the event base after a fork */
int
event_reinit(struct event_base *base)
{
const struct eventop *evsel;
int res = 0;
int was_notifiable = 0;
int had_signal_added = 0;
EVBASE_ACQUIRE_LOCK(base, th_base_lock);
evsel = base->evsel;
/* check if this event mechanism requires reinit on the backend */
if (evsel->need_reinit) {
/* We're going to call event_del() on our notify events (the
* ones that tell about signals and wakeup events). But we
* don't actually want to tell the backend to change its
* state, since it might still share some resource (a kqueue,
* an epoll fd) with the parent process, and we don't want to
* delete the fds from _that_ backend, we temporarily stub out
* the evsel with a replacement.
*/
base->evsel = &nil_eventop;
}
/* We need to re-create a new signal-notification fd and a new
* thread-notification fd. Otherwise, we'll still share those with
* the parent process, which would make any notification sent to them
* get received by one or both of the event loops, more or less at
* random.
*/
if (base->sig.ev_signal_added) {
event_del_nolock_(&base->sig.ev_signal, EVENT_DEL_AUTOBLOCK);
event_debug_unassign(&base->sig.ev_signal);
memset(&base->sig.ev_signal, 0, sizeof(base->sig.ev_signal));
if (base->sig.ev_signal_pair[0] != -1)
EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[0]);
if (base->sig.ev_signal_pair[1] != -1)
EVUTIL_CLOSESOCKET(base->sig.ev_signal_pair[1]);
had_signal_added = 1;
base->sig.ev_signal_added = 0;
}
if (base->th_notify_fn != NULL) {
was_notifiable = 1;
base->th_notify_fn = NULL;
}
if (base->th_notify_fd[0] != -1) {
event_del_nolock_(&base->th_notify, EVENT_DEL_AUTOBLOCK);
EVUTIL_CLOSESOCKET(base->th_notify_fd[0]);
if (base->th_notify_fd[1] != -1)
EVUTIL_CLOSESOCKET(base->th_notify_fd[1]);
base->th_notify_fd[0] = -1;
base->th_notify_fd[1] = -1;
event_debug_unassign(&base->th_notify);
}
/* Replace the original evsel. */
base->evsel = evsel;
if (evsel->need_reinit) {
/* Reconstruct the backend through brute-force, so that we do
* not share any structures with the parent process. For some
* backends, this is necessary: epoll and kqueue, for
* instance, have events associated with a kernel
* structure. If didn't reinitialize, we'd share that
* structure with the parent process, and any changes made by
* the parent would affect our backend's behavior (and vice
* versa).
*/
if (base->evsel->dealloc != NULL)
base->evsel->dealloc(base);
base->evbase = evsel->init(base);
if (base->evbase == NULL) {
event_errx(1,
"%s: could not reinitialize event mechanism",
__func__);
res = -1;
goto done;
}
/* Empty out the changelist (if any): we are starting from a
* blank slate. */
event_changelist_freemem_(&base->changelist);
/* Tell the event maps to re-inform the backend about all
* pending events. This will make the signal notification
* event get re-created if necessary. */
if (evmap_reinit_(base) < 0)
res = -1;
} else {
if (had_signal_added)
res = evsig_init_(base);
}
/* If we were notifiable before, and nothing just exploded, become
* notifiable again. */
if (was_notifiable && res == 0)
res = evthread_make_base_notifiable_nolock_(base);
done:
EVBASE_RELEASE_LOCK(base, th_base_lock);
return (res);
}
const char **
event_get_supported_methods(void)
{
static const char **methods = NULL;
const struct eventop **method;