… | |
… | |
3 | libev - a high performance full-featured event loop written in C |
3 | libev - a high performance full-featured event loop written in C |
4 | |
4 | |
5 | =head1 SYNOPSIS |
5 | =head1 SYNOPSIS |
6 | |
6 | |
7 | #include <ev.h> |
7 | #include <ev.h> |
|
|
8 | |
|
|
9 | =head1 EXAMPLE PROGRAM |
|
|
10 | |
|
|
11 | #include <ev.h> |
|
|
12 | |
|
|
13 | ev_io stdin_watcher; |
|
|
14 | ev_timer timeout_watcher; |
|
|
15 | |
|
|
16 | /* called when data readable on stdin */ |
|
|
17 | static void |
|
|
18 | stdin_cb (EV_P_ struct ev_io *w, int revents) |
|
|
19 | { |
|
|
20 | /* puts ("stdin ready"); */ |
|
|
21 | ev_io_stop (EV_A_ w); /* just a syntax example */ |
|
|
22 | ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */ |
|
|
23 | } |
|
|
24 | |
|
|
25 | static void |
|
|
26 | timeout_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
27 | { |
|
|
28 | /* puts ("timeout"); */ |
|
|
29 | ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */ |
|
|
30 | } |
|
|
31 | |
|
|
32 | int |
|
|
33 | main (void) |
|
|
34 | { |
|
|
35 | struct ev_loop *loop = ev_default_loop (0); |
|
|
36 | |
|
|
37 | /* initialise an io watcher, then start it */ |
|
|
38 | ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ); |
|
|
39 | ev_io_start (loop, &stdin_watcher); |
|
|
40 | |
|
|
41 | /* simple non-repeating 5.5 second timeout */ |
|
|
42 | ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.); |
|
|
43 | ev_timer_start (loop, &timeout_watcher); |
|
|
44 | |
|
|
45 | /* loop till timeout or data ready */ |
|
|
46 | ev_loop (loop, 0); |
|
|
47 | |
|
|
48 | return 0; |
|
|
49 | } |
8 | |
50 | |
9 | =head1 DESCRIPTION |
51 | =head1 DESCRIPTION |
10 | |
52 | |
11 | Libev is an event loop: you register interest in certain events (such as a |
53 | Libev is an event loop: you register interest in certain events (such as a |
12 | file descriptor being readable or a timeout occuring), and it will manage |
54 | file descriptor being readable or a timeout occuring), and it will manage |
… | |
… | |
21 | details of the event, and then hand it over to libev by I<starting> the |
63 | details of the event, and then hand it over to libev by I<starting> the |
22 | watcher. |
64 | watcher. |
23 | |
65 | |
24 | =head1 FEATURES |
66 | =head1 FEATURES |
25 | |
67 | |
26 | Libev supports select, poll, the linux-specific epoll and the bsd-specific |
68 | Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the |
27 | kqueue mechanisms for file descriptor events, relative timers, absolute |
69 | BSD-specific C<kqueue> and the Solaris-specific event port mechanisms |
28 | timers with customised rescheduling, signal events, process status change |
70 | for file descriptor events (C<ev_io>), the Linux C<inotify> interface |
29 | events (related to SIGCHLD), and event watchers dealing with the event |
71 | (for C<ev_stat>), relative timers (C<ev_timer>), absolute timers |
30 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
72 | with customised rescheduling (C<ev_periodic>), synchronous signals |
|
|
73 | (C<ev_signal>), process status change events (C<ev_child>), and event |
|
|
74 | watchers dealing with the event loop mechanism itself (C<ev_idle>, |
|
|
75 | C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as |
|
|
76 | file watchers (C<ev_stat>) and even limited support for fork events |
|
|
77 | (C<ev_fork>). |
|
|
78 | |
|
|
79 | It also is quite fast (see this |
31 | fast (see this L<benchmark|http://libev.schmorp.de/bench.html> comparing |
80 | L<benchmark|http://libev.schmorp.de/bench.html> comparing it to libevent |
32 | it to libevent for example). |
81 | for example). |
33 | |
82 | |
34 | =head1 CONVENTIONS |
83 | =head1 CONVENTIONS |
35 | |
84 | |
36 | Libev is very configurable. In this manual the default configuration |
85 | Libev is very configurable. In this manual the default configuration will |
37 | will be described, which supports multiple event loops. For more info |
86 | be described, which supports multiple event loops. For more info about |
38 | about various configuration options please have a look at the file |
87 | various configuration options please have a look at B<EMBED> section in |
39 | F<README.embed> in the libev distribution. If libev was configured without |
88 | this manual. If libev was configured without support for multiple event |
40 | support for multiple event loops, then all functions taking an initial |
89 | loops, then all functions taking an initial argument of name C<loop> |
41 | argument of name C<loop> (which is always of type C<struct ev_loop *>) |
90 | (which is always of type C<struct ev_loop *>) will not have this argument. |
42 | will not have this argument. |
|
|
43 | |
91 | |
44 | =head1 TIME REPRESENTATION |
92 | =head1 TIME REPRESENTATION |
45 | |
93 | |
46 | Libev represents time as a single floating point number, representing the |
94 | Libev represents time as a single floating point number, representing the |
47 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
95 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
48 | the beginning of 1970, details are complicated, don't ask). This type is |
96 | the beginning of 1970, details are complicated, don't ask). This type is |
49 | called C<ev_tstamp>, which is what you should use too. It usually aliases |
97 | called C<ev_tstamp>, which is what you should use too. It usually aliases |
50 | to the C<double> type in C, and when you need to do any calculations on |
98 | to the C<double> type in C, and when you need to do any calculations on |
51 | it, you should treat it as such. |
99 | it, you should treat it as such. |
52 | |
100 | |
53 | |
|
|
54 | =head1 GLOBAL FUNCTIONS |
101 | =head1 GLOBAL FUNCTIONS |
55 | |
102 | |
56 | These functions can be called anytime, even before initialising the |
103 | These functions can be called anytime, even before initialising the |
57 | library in any way. |
104 | library in any way. |
58 | |
105 | |
… | |
… | |
77 | Usually, it's a good idea to terminate if the major versions mismatch, |
124 | Usually, it's a good idea to terminate if the major versions mismatch, |
78 | as this indicates an incompatible change. Minor versions are usually |
125 | as this indicates an incompatible change. Minor versions are usually |
79 | compatible to older versions, so a larger minor version alone is usually |
126 | compatible to older versions, so a larger minor version alone is usually |
80 | not a problem. |
127 | not a problem. |
81 | |
128 | |
82 | Example: make sure we haven't accidentally been linked against the wrong |
129 | Example: Make sure we haven't accidentally been linked against the wrong |
83 | version: |
130 | version. |
84 | |
131 | |
85 | assert (("libev version mismatch", |
132 | assert (("libev version mismatch", |
86 | ev_version_major () == EV_VERSION_MAJOR |
133 | ev_version_major () == EV_VERSION_MAJOR |
87 | && ev_version_minor () >= EV_VERSION_MINOR)); |
134 | && ev_version_minor () >= EV_VERSION_MINOR)); |
88 | |
135 | |
… | |
… | |
118 | |
165 | |
119 | See the description of C<ev_embed> watchers for more info. |
166 | See the description of C<ev_embed> watchers for more info. |
120 | |
167 | |
121 | =item ev_set_allocator (void *(*cb)(void *ptr, long size)) |
168 | =item ev_set_allocator (void *(*cb)(void *ptr, long size)) |
122 | |
169 | |
123 | Sets the allocation function to use (the prototype is similar to the |
170 | Sets the allocation function to use (the prototype is similar - the |
124 | realloc C function, the semantics are identical). It is used to allocate |
171 | semantics is identical - to the realloc C function). It is used to |
125 | and free memory (no surprises here). If it returns zero when memory |
172 | allocate and free memory (no surprises here). If it returns zero when |
126 | needs to be allocated, the library might abort or take some potentially |
173 | memory needs to be allocated, the library might abort or take some |
127 | destructive action. The default is your system realloc function. |
174 | potentially destructive action. The default is your system realloc |
|
|
175 | function. |
128 | |
176 | |
129 | You could override this function in high-availability programs to, say, |
177 | You could override this function in high-availability programs to, say, |
130 | free some memory if it cannot allocate memory, to use a special allocator, |
178 | free some memory if it cannot allocate memory, to use a special allocator, |
131 | or even to sleep a while and retry until some memory is available. |
179 | or even to sleep a while and retry until some memory is available. |
132 | |
180 | |
133 | Example: replace the libev allocator with one that waits a bit and then |
181 | Example: Replace the libev allocator with one that waits a bit and then |
134 | retries: better than mine). |
182 | retries). |
135 | |
183 | |
136 | static void * |
184 | static void * |
137 | persistent_realloc (void *ptr, long size) |
185 | persistent_realloc (void *ptr, size_t size) |
138 | { |
186 | { |
139 | for (;;) |
187 | for (;;) |
140 | { |
188 | { |
141 | void *newptr = realloc (ptr, size); |
189 | void *newptr = realloc (ptr, size); |
142 | |
190 | |
… | |
… | |
158 | callback is set, then libev will expect it to remedy the sitution, no |
206 | callback is set, then libev will expect it to remedy the sitution, no |
159 | matter what, when it returns. That is, libev will generally retry the |
207 | matter what, when it returns. That is, libev will generally retry the |
160 | requested operation, or, if the condition doesn't go away, do bad stuff |
208 | requested operation, or, if the condition doesn't go away, do bad stuff |
161 | (such as abort). |
209 | (such as abort). |
162 | |
210 | |
163 | Example: do the same thing as libev does internally: |
211 | Example: This is basically the same thing that libev does internally, too. |
164 | |
212 | |
165 | static void |
213 | static void |
166 | fatal_error (const char *msg) |
214 | fatal_error (const char *msg) |
167 | { |
215 | { |
168 | perror (msg); |
216 | perror (msg); |
… | |
… | |
218 | C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will |
266 | C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will |
219 | override the flags completely if it is found in the environment. This is |
267 | override the flags completely if it is found in the environment. This is |
220 | useful to try out specific backends to test their performance, or to work |
268 | useful to try out specific backends to test their performance, or to work |
221 | around bugs. |
269 | around bugs. |
222 | |
270 | |
|
|
271 | =item C<EVFLAG_FORKCHECK> |
|
|
272 | |
|
|
273 | Instead of calling C<ev_default_fork> or C<ev_loop_fork> manually after |
|
|
274 | a fork, you can also make libev check for a fork in each iteration by |
|
|
275 | enabling this flag. |
|
|
276 | |
|
|
277 | This works by calling C<getpid ()> on every iteration of the loop, |
|
|
278 | and thus this might slow down your event loop if you do a lot of loop |
|
|
279 | iterations and little real work, but is usually not noticeable (on my |
|
|
280 | Linux system for example, C<getpid> is actually a simple 5-insn sequence |
|
|
281 | without a syscall and thus I<very> fast, but my Linux system also has |
|
|
282 | C<pthread_atfork> which is even faster). |
|
|
283 | |
|
|
284 | The big advantage of this flag is that you can forget about fork (and |
|
|
285 | forget about forgetting to tell libev about forking) when you use this |
|
|
286 | flag. |
|
|
287 | |
|
|
288 | This flag setting cannot be overriden or specified in the C<LIBEV_FLAGS> |
|
|
289 | environment variable. |
|
|
290 | |
223 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
291 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
224 | |
292 | |
225 | This is your standard select(2) backend. Not I<completely> standard, as |
293 | This is your standard select(2) backend. Not I<completely> standard, as |
226 | libev tries to roll its own fd_set with no limits on the number of fds, |
294 | libev tries to roll its own fd_set with no limits on the number of fds, |
227 | but if that fails, expect a fairly low limit on the number of fds when |
295 | but if that fails, expect a fairly low limit on the number of fds when |
… | |
… | |
314 | Similar to C<ev_default_loop>, but always creates a new event loop that is |
382 | Similar to C<ev_default_loop>, but always creates a new event loop that is |
315 | always distinct from the default loop. Unlike the default loop, it cannot |
383 | always distinct from the default loop. Unlike the default loop, it cannot |
316 | handle signal and child watchers, and attempts to do so will be greeted by |
384 | handle signal and child watchers, and attempts to do so will be greeted by |
317 | undefined behaviour (or a failed assertion if assertions are enabled). |
385 | undefined behaviour (or a failed assertion if assertions are enabled). |
318 | |
386 | |
319 | Example: try to create a event loop that uses epoll and nothing else. |
387 | Example: Try to create a event loop that uses epoll and nothing else. |
320 | |
388 | |
321 | struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
389 | struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
322 | if (!epoller) |
390 | if (!epoller) |
323 | fatal ("no epoll found here, maybe it hides under your chair"); |
391 | fatal ("no epoll found here, maybe it hides under your chair"); |
324 | |
392 | |
… | |
… | |
423 | Signals and child watchers are implemented as I/O watchers, and will |
491 | Signals and child watchers are implemented as I/O watchers, and will |
424 | be handled here by queueing them when their watcher gets executed. |
492 | be handled here by queueing them when their watcher gets executed. |
425 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
493 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
426 | were used, return, otherwise continue with step *. |
494 | were used, return, otherwise continue with step *. |
427 | |
495 | |
428 | Example: queue some jobs and then loop until no events are outsanding |
496 | Example: Queue some jobs and then loop until no events are outsanding |
429 | anymore. |
497 | anymore. |
430 | |
498 | |
431 | ... queue jobs here, make sure they register event watchers as long |
499 | ... queue jobs here, make sure they register event watchers as long |
432 | ... as they still have work to do (even an idle watcher will do..) |
500 | ... as they still have work to do (even an idle watcher will do..) |
433 | ev_loop (my_loop, 0); |
501 | ev_loop (my_loop, 0); |
… | |
… | |
453 | visible to the libev user and should not keep C<ev_loop> from exiting if |
521 | visible to the libev user and should not keep C<ev_loop> from exiting if |
454 | no event watchers registered by it are active. It is also an excellent |
522 | no event watchers registered by it are active. It is also an excellent |
455 | way to do this for generic recurring timers or from within third-party |
523 | way to do this for generic recurring timers or from within third-party |
456 | libraries. Just remember to I<unref after start> and I<ref before stop>. |
524 | libraries. Just remember to I<unref after start> and I<ref before stop>. |
457 | |
525 | |
458 | Example: create a signal watcher, but keep it from keeping C<ev_loop> |
526 | Example: Create a signal watcher, but keep it from keeping C<ev_loop> |
459 | running when nothing else is active. |
527 | running when nothing else is active. |
460 | |
528 | |
461 | struct dv_signal exitsig; |
529 | struct ev_signal exitsig; |
462 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
530 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
463 | ev_signal_start (myloop, &exitsig); |
531 | ev_signal_start (loop, &exitsig); |
464 | evf_unref (myloop); |
532 | evf_unref (loop); |
465 | |
533 | |
466 | Example: for some weird reason, unregister the above signal handler again. |
534 | Example: For some weird reason, unregister the above signal handler again. |
467 | |
535 | |
468 | ev_ref (myloop); |
536 | ev_ref (loop); |
469 | ev_signal_stop (myloop, &exitsig); |
537 | ev_signal_stop (loop, &exitsig); |
470 | |
538 | |
471 | =back |
539 | =back |
472 | |
540 | |
473 | |
541 | |
474 | =head1 ANATOMY OF A WATCHER |
542 | =head1 ANATOMY OF A WATCHER |
… | |
… | |
565 | received events. Callbacks of both watcher types can start and stop as |
633 | received events. Callbacks of both watcher types can start and stop as |
566 | many watchers as they want, and all of them will be taken into account |
634 | many watchers as they want, and all of them will be taken into account |
567 | (for example, a C<ev_prepare> watcher might start an idle watcher to keep |
635 | (for example, a C<ev_prepare> watcher might start an idle watcher to keep |
568 | C<ev_loop> from blocking). |
636 | C<ev_loop> from blocking). |
569 | |
637 | |
|
|
638 | =item C<EV_EMBED> |
|
|
639 | |
|
|
640 | The embedded event loop specified in the C<ev_embed> watcher needs attention. |
|
|
641 | |
|
|
642 | =item C<EV_FORK> |
|
|
643 | |
|
|
644 | The event loop has been resumed in the child process after fork (see |
|
|
645 | C<ev_fork>). |
|
|
646 | |
570 | =item C<EV_ERROR> |
647 | =item C<EV_ERROR> |
571 | |
648 | |
572 | An unspecified error has occured, the watcher has been stopped. This might |
649 | An unspecified error has occured, the watcher has been stopped. This might |
573 | happen because the watcher could not be properly started because libev |
650 | happen because the watcher could not be properly started because libev |
574 | ran out of memory, a file descriptor was found to be closed or any other |
651 | ran out of memory, a file descriptor was found to be closed or any other |
… | |
… | |
648 | events but its callback has not yet been invoked). As long as a watcher |
725 | events but its callback has not yet been invoked). As long as a watcher |
649 | is pending (but not active) you must not call an init function on it (but |
726 | is pending (but not active) you must not call an init function on it (but |
650 | C<ev_TYPE_set> is safe) and you must make sure the watcher is available to |
727 | C<ev_TYPE_set> is safe) and you must make sure the watcher is available to |
651 | libev (e.g. you cnanot C<free ()> it). |
728 | libev (e.g. you cnanot C<free ()> it). |
652 | |
729 | |
653 | =item callback = ev_cb (ev_TYPE *watcher) |
730 | =item callback ev_cb (ev_TYPE *watcher) |
654 | |
731 | |
655 | Returns the callback currently set on the watcher. |
732 | Returns the callback currently set on the watcher. |
656 | |
733 | |
657 | =item ev_cb_set (ev_TYPE *watcher, callback) |
734 | =item ev_cb_set (ev_TYPE *watcher, callback) |
658 | |
735 | |
… | |
… | |
686 | { |
763 | { |
687 | struct my_io *w = (struct my_io *)w_; |
764 | struct my_io *w = (struct my_io *)w_; |
688 | ... |
765 | ... |
689 | } |
766 | } |
690 | |
767 | |
691 | More interesting and less C-conformant ways of catsing your callback type |
768 | More interesting and less C-conformant ways of casting your callback type |
692 | have been omitted.... |
769 | instead have been omitted. |
|
|
770 | |
|
|
771 | Another common scenario is having some data structure with multiple |
|
|
772 | watchers: |
|
|
773 | |
|
|
774 | struct my_biggy |
|
|
775 | { |
|
|
776 | int some_data; |
|
|
777 | ev_timer t1; |
|
|
778 | ev_timer t2; |
|
|
779 | } |
|
|
780 | |
|
|
781 | In this case getting the pointer to C<my_biggy> is a bit more complicated, |
|
|
782 | you need to use C<offsetof>: |
|
|
783 | |
|
|
784 | #include <stddef.h> |
|
|
785 | |
|
|
786 | static void |
|
|
787 | t1_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
788 | { |
|
|
789 | struct my_biggy big = (struct my_biggy * |
|
|
790 | (((char *)w) - offsetof (struct my_biggy, t1)); |
|
|
791 | } |
|
|
792 | |
|
|
793 | static void |
|
|
794 | t2_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
795 | { |
|
|
796 | struct my_biggy big = (struct my_biggy * |
|
|
797 | (((char *)w) - offsetof (struct my_biggy, t2)); |
|
|
798 | } |
693 | |
799 | |
694 | |
800 | |
695 | =head1 WATCHER TYPES |
801 | =head1 WATCHER TYPES |
696 | |
802 | |
697 | This section describes each watcher in detail, but will not repeat |
803 | This section describes each watcher in detail, but will not repeat |
… | |
… | |
766 | |
872 | |
767 | The events being watched. |
873 | The events being watched. |
768 | |
874 | |
769 | =back |
875 | =back |
770 | |
876 | |
771 | Example: call C<stdin_readable_cb> when STDIN_FILENO has become, well |
877 | Example: Call C<stdin_readable_cb> when STDIN_FILENO has become, well |
772 | readable, but only once. Since it is likely line-buffered, you could |
878 | readable, but only once. Since it is likely line-buffered, you could |
773 | attempt to read a whole line in the callback: |
879 | attempt to read a whole line in the callback. |
774 | |
880 | |
775 | static void |
881 | static void |
776 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
882 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
777 | { |
883 | { |
778 | ev_io_stop (loop, w); |
884 | ev_io_stop (loop, w); |
… | |
… | |
830 | =item ev_timer_again (loop) |
936 | =item ev_timer_again (loop) |
831 | |
937 | |
832 | This will act as if the timer timed out and restart it again if it is |
938 | This will act as if the timer timed out and restart it again if it is |
833 | repeating. The exact semantics are: |
939 | repeating. The exact semantics are: |
834 | |
940 | |
|
|
941 | If the timer is pending, its pending status is cleared. |
|
|
942 | |
835 | If the timer is started but nonrepeating, stop it. |
943 | If the timer is started but nonrepeating, stop it (as if it timed out). |
836 | |
944 | |
837 | If the timer is repeating, either start it if necessary (with the repeat |
945 | If the timer is repeating, either start it if necessary (with the |
838 | value), or reset the running timer to the repeat value. |
946 | C<repeat> value), or reset the running timer to the C<repeat> value. |
839 | |
947 | |
840 | This sounds a bit complicated, but here is a useful and typical |
948 | This sounds a bit complicated, but here is a useful and typical |
841 | example: Imagine you have a tcp connection and you want a so-called |
949 | example: Imagine you have a tcp connection and you want a so-called idle |
842 | idle timeout, that is, you want to be called when there have been, |
950 | timeout, that is, you want to be called when there have been, say, 60 |
843 | say, 60 seconds of inactivity on the socket. The easiest way to do |
951 | seconds of inactivity on the socket. The easiest way to do this is to |
844 | this is to configure an C<ev_timer> with C<after>=C<repeat>=C<60> and calling |
952 | configure an C<ev_timer> with a C<repeat> value of C<60> and then call |
845 | C<ev_timer_again> each time you successfully read or write some data. If |
953 | C<ev_timer_again> each time you successfully read or write some data. If |
846 | you go into an idle state where you do not expect data to travel on the |
954 | you go into an idle state where you do not expect data to travel on the |
847 | socket, you can stop the timer, and again will automatically restart it if |
955 | socket, you can C<ev_timer_stop> the timer, and C<ev_timer_again> will |
848 | need be. |
956 | automatically restart it if need be. |
849 | |
957 | |
850 | You can also ignore the C<after> value and C<ev_timer_start> altogether |
958 | That means you can ignore the C<after> value and C<ev_timer_start> |
851 | and only ever use the C<repeat> value: |
959 | altogether and only ever use the C<repeat> value and C<ev_timer_again>: |
852 | |
960 | |
853 | ev_timer_init (timer, callback, 0., 5.); |
961 | ev_timer_init (timer, callback, 0., 5.); |
854 | ev_timer_again (loop, timer); |
962 | ev_timer_again (loop, timer); |
855 | ... |
963 | ... |
856 | timer->again = 17.; |
964 | timer->again = 17.; |
857 | ev_timer_again (loop, timer); |
965 | ev_timer_again (loop, timer); |
858 | ... |
966 | ... |
859 | timer->again = 10.; |
967 | timer->again = 10.; |
860 | ev_timer_again (loop, timer); |
968 | ev_timer_again (loop, timer); |
861 | |
969 | |
862 | This is more efficient then stopping/starting the timer eahc time you want |
970 | This is more slightly efficient then stopping/starting the timer each time |
863 | to modify its timeout value. |
971 | you want to modify its timeout value. |
864 | |
972 | |
865 | =item ev_tstamp repeat [read-write] |
973 | =item ev_tstamp repeat [read-write] |
866 | |
974 | |
867 | The current C<repeat> value. Will be used each time the watcher times out |
975 | The current C<repeat> value. Will be used each time the watcher times out |
868 | or C<ev_timer_again> is called and determines the next timeout (if any), |
976 | or C<ev_timer_again> is called and determines the next timeout (if any), |
869 | which is also when any modifications are taken into account. |
977 | which is also when any modifications are taken into account. |
870 | |
978 | |
871 | =back |
979 | =back |
872 | |
980 | |
873 | Example: create a timer that fires after 60 seconds. |
981 | Example: Create a timer that fires after 60 seconds. |
874 | |
982 | |
875 | static void |
983 | static void |
876 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
984 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
877 | { |
985 | { |
878 | .. one minute over, w is actually stopped right here |
986 | .. one minute over, w is actually stopped right here |
… | |
… | |
880 | |
988 | |
881 | struct ev_timer mytimer; |
989 | struct ev_timer mytimer; |
882 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
990 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
883 | ev_timer_start (loop, &mytimer); |
991 | ev_timer_start (loop, &mytimer); |
884 | |
992 | |
885 | Example: create a timeout timer that times out after 10 seconds of |
993 | Example: Create a timeout timer that times out after 10 seconds of |
886 | inactivity. |
994 | inactivity. |
887 | |
995 | |
888 | static void |
996 | static void |
889 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
997 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
890 | { |
998 | { |
… | |
… | |
1015 | switched off. Can be changed any time, but changes only take effect when |
1123 | switched off. Can be changed any time, but changes only take effect when |
1016 | the periodic timer fires or C<ev_periodic_again> is being called. |
1124 | the periodic timer fires or C<ev_periodic_again> is being called. |
1017 | |
1125 | |
1018 | =back |
1126 | =back |
1019 | |
1127 | |
1020 | Example: call a callback every hour, or, more precisely, whenever the |
1128 | Example: Call a callback every hour, or, more precisely, whenever the |
1021 | system clock is divisible by 3600. The callback invocation times have |
1129 | system clock is divisible by 3600. The callback invocation times have |
1022 | potentially a lot of jittering, but good long-term stability. |
1130 | potentially a lot of jittering, but good long-term stability. |
1023 | |
1131 | |
1024 | static void |
1132 | static void |
1025 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1133 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
… | |
… | |
1029 | |
1137 | |
1030 | struct ev_periodic hourly_tick; |
1138 | struct ev_periodic hourly_tick; |
1031 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1139 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1032 | ev_periodic_start (loop, &hourly_tick); |
1140 | ev_periodic_start (loop, &hourly_tick); |
1033 | |
1141 | |
1034 | Example: the same as above, but use a reschedule callback to do it: |
1142 | Example: The same as above, but use a reschedule callback to do it: |
1035 | |
1143 | |
1036 | #include <math.h> |
1144 | #include <math.h> |
1037 | |
1145 | |
1038 | static ev_tstamp |
1146 | static ev_tstamp |
1039 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
1147 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
… | |
… | |
1041 | return fmod (now, 3600.) + 3600.; |
1149 | return fmod (now, 3600.) + 3600.; |
1042 | } |
1150 | } |
1043 | |
1151 | |
1044 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1152 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1045 | |
1153 | |
1046 | Example: call a callback every hour, starting now: |
1154 | Example: Call a callback every hour, starting now: |
1047 | |
1155 | |
1048 | struct ev_periodic hourly_tick; |
1156 | struct ev_periodic hourly_tick; |
1049 | ev_periodic_init (&hourly_tick, clock_cb, |
1157 | ev_periodic_init (&hourly_tick, clock_cb, |
1050 | fmod (ev_now (loop), 3600.), 3600., 0); |
1158 | fmod (ev_now (loop), 3600.), 3600., 0); |
1051 | ev_periodic_start (loop, &hourly_tick); |
1159 | ev_periodic_start (loop, &hourly_tick); |
… | |
… | |
1112 | The process exit/trace status caused by C<rpid> (see your systems |
1220 | The process exit/trace status caused by C<rpid> (see your systems |
1113 | C<waitpid> and C<sys/wait.h> documentation for details). |
1221 | C<waitpid> and C<sys/wait.h> documentation for details). |
1114 | |
1222 | |
1115 | =back |
1223 | =back |
1116 | |
1224 | |
1117 | Example: try to exit cleanly on SIGINT and SIGTERM. |
1225 | Example: Try to exit cleanly on SIGINT and SIGTERM. |
1118 | |
1226 | |
1119 | static void |
1227 | static void |
1120 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1228 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1121 | { |
1229 | { |
1122 | ev_unloop (loop, EVUNLOOP_ALL); |
1230 | ev_unloop (loop, EVUNLOOP_ALL); |
… | |
… | |
1137 | not exist" is a status change like any other. The condition "path does |
1245 | not exist" is a status change like any other. The condition "path does |
1138 | not exist" is signified by the C<st_nlink> field being zero (which is |
1246 | not exist" is signified by the C<st_nlink> field being zero (which is |
1139 | otherwise always forced to be at least one) and all the other fields of |
1247 | otherwise always forced to be at least one) and all the other fields of |
1140 | the stat buffer having unspecified contents. |
1248 | the stat buffer having unspecified contents. |
1141 | |
1249 | |
|
|
1250 | The path I<should> be absolute and I<must not> end in a slash. If it is |
|
|
1251 | relative and your working directory changes, the behaviour is undefined. |
|
|
1252 | |
1142 | Since there is no standard to do this, the portable implementation simply |
1253 | Since there is no standard to do this, the portable implementation simply |
1143 | calls C<stat (2)> regulalry on the path to see if it changed somehow. You |
1254 | calls C<stat (2)> regularly on the path to see if it changed somehow. You |
1144 | can specify a recommended polling interval for this case. If you specify |
1255 | can specify a recommended polling interval for this case. If you specify |
1145 | a polling interval of C<0> (highly recommended!) then a I<suitable, |
1256 | a polling interval of C<0> (highly recommended!) then a I<suitable, |
1146 | unspecified default> value will be used (which you can expect to be around |
1257 | unspecified default> value will be used (which you can expect to be around |
1147 | five seconds, although this might change dynamically). Libev will also |
1258 | five seconds, although this might change dynamically). Libev will also |
1148 | impose a minimum interval which is currently around C<0.1>, but thats |
1259 | impose a minimum interval which is currently around C<0.1>, but thats |
… | |
… | |
1150 | |
1261 | |
1151 | This watcher type is not meant for massive numbers of stat watchers, |
1262 | This watcher type is not meant for massive numbers of stat watchers, |
1152 | as even with OS-supported change notifications, this can be |
1263 | as even with OS-supported change notifications, this can be |
1153 | resource-intensive. |
1264 | resource-intensive. |
1154 | |
1265 | |
1155 | At the time of this writing, no specific OS backends are implemented, but |
1266 | At the time of this writing, only the Linux inotify interface is |
1156 | if demand increases, at least a kqueue and inotify backend will be added. |
1267 | implemented (implementing kqueue support is left as an exercise for the |
|
|
1268 | reader). Inotify will be used to give hints only and should not change the |
|
|
1269 | semantics of C<ev_stat> watchers, which means that libev sometimes needs |
|
|
1270 | to fall back to regular polling again even with inotify, but changes are |
|
|
1271 | usually detected immediately, and if the file exists there will be no |
|
|
1272 | polling. |
1157 | |
1273 | |
1158 | =over 4 |
1274 | =over 4 |
1159 | |
1275 | |
1160 | =item ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval) |
1276 | =item ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval) |
1161 | |
1277 | |
… | |
… | |
1251 | kind. There is a C<ev_idle_set> macro, but using it is utterly pointless, |
1367 | kind. There is a C<ev_idle_set> macro, but using it is utterly pointless, |
1252 | believe me. |
1368 | believe me. |
1253 | |
1369 | |
1254 | =back |
1370 | =back |
1255 | |
1371 | |
1256 | Example: dynamically allocate an C<ev_idle>, start it, and in the |
1372 | Example: Dynamically allocate an C<ev_idle> watcher, start it, and in the |
1257 | callback, free it. Alos, use no error checking, as usual. |
1373 | callback, free it. Also, use no error checking, as usual. |
1258 | |
1374 | |
1259 | static void |
1375 | static void |
1260 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1376 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1261 | { |
1377 | { |
1262 | free (w); |
1378 | free (w); |
… | |
… | |
1341 | |
1457 | |
1342 | // create io watchers for each fd and a timer before blocking |
1458 | // create io watchers for each fd and a timer before blocking |
1343 | static void |
1459 | static void |
1344 | adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1460 | adns_prepare_cb (ev_loop *loop, ev_prepare *w, int revents) |
1345 | { |
1461 | { |
1346 | int timeout = 3600000;truct pollfd fds [nfd]; |
1462 | int timeout = 3600000; |
|
|
1463 | struct pollfd fds [nfd]; |
1347 | // actual code will need to loop here and realloc etc. |
1464 | // actual code will need to loop here and realloc etc. |
1348 | adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1465 | adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ())); |
1349 | |
1466 | |
1350 | /* the callback is illegal, but won't be called as we stop during check */ |
1467 | /* the callback is illegal, but won't be called as we stop during check */ |
1351 | ev_timer_init (&tw, 0, timeout * 1e-3); |
1468 | ev_timer_init (&tw, 0, timeout * 1e-3); |
… | |
… | |
1470 | The embedded event loop. |
1587 | The embedded event loop. |
1471 | |
1588 | |
1472 | =back |
1589 | =back |
1473 | |
1590 | |
1474 | |
1591 | |
|
|
1592 | =head2 C<ev_fork> - the audacity to resume the event loop after a fork |
|
|
1593 | |
|
|
1594 | Fork watchers are called when a C<fork ()> was detected (usually because |
|
|
1595 | whoever is a good citizen cared to tell libev about it by calling |
|
|
1596 | C<ev_default_fork> or C<ev_loop_fork>). The invocation is done before the |
|
|
1597 | event loop blocks next and before C<ev_check> watchers are being called, |
|
|
1598 | and only in the child after the fork. If whoever good citizen calling |
|
|
1599 | C<ev_default_fork> cheats and calls it in the wrong process, the fork |
|
|
1600 | handlers will be invoked, too, of course. |
|
|
1601 | |
|
|
1602 | =over 4 |
|
|
1603 | |
|
|
1604 | =item ev_fork_init (ev_signal *, callback) |
|
|
1605 | |
|
|
1606 | Initialises and configures the fork watcher - it has no parameters of any |
|
|
1607 | kind. There is a C<ev_fork_set> macro, but using it is utterly pointless, |
|
|
1608 | believe me. |
|
|
1609 | |
|
|
1610 | =back |
|
|
1611 | |
|
|
1612 | |
1475 | =head1 OTHER FUNCTIONS |
1613 | =head1 OTHER FUNCTIONS |
1476 | |
1614 | |
1477 | There are some other functions of possible interest. Described. Here. Now. |
1615 | There are some other functions of possible interest. Described. Here. Now. |
1478 | |
1616 | |
1479 | =over 4 |
1617 | =over 4 |
… | |
… | |
1664 | idle (this, &myclass::idle_cb) |
1802 | idle (this, &myclass::idle_cb) |
1665 | { |
1803 | { |
1666 | io.start (fd, ev::READ); |
1804 | io.start (fd, ev::READ); |
1667 | } |
1805 | } |
1668 | |
1806 | |
|
|
1807 | |
|
|
1808 | =head1 MACRO MAGIC |
|
|
1809 | |
|
|
1810 | Libev can be compiled with a variety of options, the most fundemantal is |
|
|
1811 | C<EV_MULTIPLICITY>. This option determines wether (most) functions and |
|
|
1812 | callbacks have an initial C<struct ev_loop *> argument. |
|
|
1813 | |
|
|
1814 | To make it easier to write programs that cope with either variant, the |
|
|
1815 | following macros are defined: |
|
|
1816 | |
|
|
1817 | =over 4 |
|
|
1818 | |
|
|
1819 | =item C<EV_A>, C<EV_A_> |
|
|
1820 | |
|
|
1821 | This provides the loop I<argument> for functions, if one is required ("ev |
|
|
1822 | loop argument"). The C<EV_A> form is used when this is the sole argument, |
|
|
1823 | C<EV_A_> is used when other arguments are following. Example: |
|
|
1824 | |
|
|
1825 | ev_unref (EV_A); |
|
|
1826 | ev_timer_add (EV_A_ watcher); |
|
|
1827 | ev_loop (EV_A_ 0); |
|
|
1828 | |
|
|
1829 | It assumes the variable C<loop> of type C<struct ev_loop *> is in scope, |
|
|
1830 | which is often provided by the following macro. |
|
|
1831 | |
|
|
1832 | =item C<EV_P>, C<EV_P_> |
|
|
1833 | |
|
|
1834 | This provides the loop I<parameter> for functions, if one is required ("ev |
|
|
1835 | loop parameter"). The C<EV_P> form is used when this is the sole parameter, |
|
|
1836 | C<EV_P_> is used when other parameters are following. Example: |
|
|
1837 | |
|
|
1838 | // this is how ev_unref is being declared |
|
|
1839 | static void ev_unref (EV_P); |
|
|
1840 | |
|
|
1841 | // this is how you can declare your typical callback |
|
|
1842 | static void cb (EV_P_ ev_timer *w, int revents) |
|
|
1843 | |
|
|
1844 | It declares a parameter C<loop> of type C<struct ev_loop *>, quite |
|
|
1845 | suitable for use with C<EV_A>. |
|
|
1846 | |
|
|
1847 | =item C<EV_DEFAULT>, C<EV_DEFAULT_> |
|
|
1848 | |
|
|
1849 | Similar to the other two macros, this gives you the value of the default |
|
|
1850 | loop, if multiple loops are supported ("ev loop default"). |
|
|
1851 | |
|
|
1852 | =back |
|
|
1853 | |
|
|
1854 | Example: Declare and initialise a check watcher, utilising the above |
|
|
1855 | macros so it will work regardless of wether multiple loops are supported |
|
|
1856 | or not. |
|
|
1857 | |
|
|
1858 | static void |
|
|
1859 | check_cb (EV_P_ ev_timer *w, int revents) |
|
|
1860 | { |
|
|
1861 | ev_check_stop (EV_A_ w); |
|
|
1862 | } |
|
|
1863 | |
|
|
1864 | ev_check check; |
|
|
1865 | ev_check_init (&check, check_cb); |
|
|
1866 | ev_check_start (EV_DEFAULT_ &check); |
|
|
1867 | ev_loop (EV_DEFAULT_ 0); |
|
|
1868 | |
1669 | =head1 EMBEDDING |
1869 | =head1 EMBEDDING |
1670 | |
1870 | |
1671 | Libev can (and often is) directly embedded into host |
1871 | Libev can (and often is) directly embedded into host |
1672 | applications. Examples of applications that embed it include the Deliantra |
1872 | applications. Examples of applications that embed it include the Deliantra |
1673 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
1873 | Game Server, the EV perl module, the GNU Virtual Private Ethernet (gvpe) |
… | |
… | |
1712 | ev_vars.h |
1912 | ev_vars.h |
1713 | ev_wrap.h |
1913 | ev_wrap.h |
1714 | |
1914 | |
1715 | ev_win32.c required on win32 platforms only |
1915 | ev_win32.c required on win32 platforms only |
1716 | |
1916 | |
1717 | ev_select.c only when select backend is enabled (which is by default) |
1917 | ev_select.c only when select backend is enabled (which is enabled by default) |
1718 | ev_poll.c only when poll backend is enabled (disabled by default) |
1918 | ev_poll.c only when poll backend is enabled (disabled by default) |
1719 | ev_epoll.c only when the epoll backend is enabled (disabled by default) |
1919 | ev_epoll.c only when the epoll backend is enabled (disabled by default) |
1720 | ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
1920 | ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
1721 | ev_port.c only when the solaris port backend is enabled (disabled by default) |
1921 | ev_port.c only when the solaris port backend is enabled (disabled by default) |
1722 | |
1922 | |
… | |
… | |
1847 | |
2047 | |
1848 | =item EV_USE_DEVPOLL |
2048 | =item EV_USE_DEVPOLL |
1849 | |
2049 | |
1850 | reserved for future expansion, works like the USE symbols above. |
2050 | reserved for future expansion, works like the USE symbols above. |
1851 | |
2051 | |
|
|
2052 | =item EV_USE_INOTIFY |
|
|
2053 | |
|
|
2054 | If defined to be C<1>, libev will compile in support for the Linux inotify |
|
|
2055 | interface to speed up C<ev_stat> watchers. Its actual availability will |
|
|
2056 | be detected at runtime. |
|
|
2057 | |
1852 | =item EV_H |
2058 | =item EV_H |
1853 | |
2059 | |
1854 | The name of the F<ev.h> header file used to include it. The default if |
2060 | The name of the F<ev.h> header file used to include it. The default if |
1855 | undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This |
2061 | undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This |
1856 | can be used to virtually rename the F<ev.h> header file in case of conflicts. |
2062 | can be used to virtually rename the F<ev.h> header file in case of conflicts. |
… | |
… | |
1895 | =item EV_STAT_ENABLE |
2101 | =item EV_STAT_ENABLE |
1896 | |
2102 | |
1897 | If undefined or defined to be C<1>, then stat watchers are supported. If |
2103 | If undefined or defined to be C<1>, then stat watchers are supported. If |
1898 | defined to be C<0>, then they are not. |
2104 | defined to be C<0>, then they are not. |
1899 | |
2105 | |
|
|
2106 | =item EV_FORK_ENABLE |
|
|
2107 | |
|
|
2108 | If undefined or defined to be C<1>, then fork watchers are supported. If |
|
|
2109 | defined to be C<0>, then they are not. |
|
|
2110 | |
1900 | =item EV_MINIMAL |
2111 | =item EV_MINIMAL |
1901 | |
2112 | |
1902 | If you need to shave off some kilobytes of code at the expense of some |
2113 | If you need to shave off some kilobytes of code at the expense of some |
1903 | speed, define this symbol to C<1>. Currently only used for gcc to override |
2114 | speed, define this symbol to C<1>. Currently only used for gcc to override |
1904 | some inlining decisions, saves roughly 30% codesize of amd64. |
2115 | some inlining decisions, saves roughly 30% codesize of amd64. |
|
|
2116 | |
|
|
2117 | =item EV_PID_HASHSIZE |
|
|
2118 | |
|
|
2119 | C<ev_child> watchers use a small hash table to distribute workload by |
|
|
2120 | pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more |
|
|
2121 | than enough. If you need to manage thousands of children you might want to |
|
|
2122 | increase this value (I<must> be a power of two). |
|
|
2123 | |
|
|
2124 | =item EV_INOTIFY_HASHSIZE |
|
|
2125 | |
|
|
2126 | C<ev_staz> watchers use a small hash table to distribute workload by |
|
|
2127 | inotify watch id. The default size is C<16> (or C<1> with C<EV_MINIMAL>), |
|
|
2128 | usually more than enough. If you need to manage thousands of C<ev_stat> |
|
|
2129 | watchers you might want to increase this value (I<must> be a power of |
|
|
2130 | two). |
1905 | |
2131 | |
1906 | =item EV_COMMON |
2132 | =item EV_COMMON |
1907 | |
2133 | |
1908 | By default, all watchers have a C<void *data> member. By redefining |
2134 | By default, all watchers have a C<void *data> member. By redefining |
1909 | this macro to a something else you can include more and other types of |
2135 | this macro to a something else you can include more and other types of |
… | |
… | |
1938 | interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file |
2164 | interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file |
1939 | will be compiled. It is pretty complex because it provides its own header |
2165 | will be compiled. It is pretty complex because it provides its own header |
1940 | file. |
2166 | file. |
1941 | |
2167 | |
1942 | The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file |
2168 | The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file |
1943 | that everybody includes and which overrides some autoconf choices: |
2169 | that everybody includes and which overrides some configure choices: |
1944 | |
2170 | |
|
|
2171 | #define EV_MINIMAL 1 |
1945 | #define EV_USE_POLL 0 |
2172 | #define EV_USE_POLL 0 |
1946 | #define EV_MULTIPLICITY 0 |
2173 | #define EV_MULTIPLICITY 0 |
1947 | #define EV_PERIODICS 0 |
2174 | #define EV_PERIODIC_ENABLE 0 |
|
|
2175 | #define EV_STAT_ENABLE 0 |
|
|
2176 | #define EV_FORK_ENABLE 0 |
1948 | #define EV_CONFIG_H <config.h> |
2177 | #define EV_CONFIG_H <config.h> |
|
|
2178 | #define EV_MINPRI 0 |
|
|
2179 | #define EV_MAXPRI 0 |
1949 | |
2180 | |
1950 | #include "ev++.h" |
2181 | #include "ev++.h" |
1951 | |
2182 | |
1952 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
2183 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
1953 | |
2184 | |
… | |
… | |
1969 | |
2200 | |
1970 | =item Starting io/check/prepare/idle/signal/child watchers: O(1) |
2201 | =item Starting io/check/prepare/idle/signal/child watchers: O(1) |
1971 | |
2202 | |
1972 | =item Stopping check/prepare/idle watchers: O(1) |
2203 | =item Stopping check/prepare/idle watchers: O(1) |
1973 | |
2204 | |
1974 | =item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16)) |
2205 | =item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE)) |
1975 | |
2206 | |
1976 | =item Finding the next timer per loop iteration: O(1) |
2207 | =item Finding the next timer per loop iteration: O(1) |
1977 | |
2208 | |
1978 | =item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd) |
2209 | =item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd) |
1979 | |
2210 | |