… | |
… | |
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>), relative timers (C<ev_timer>), |
29 | events (related to SIGCHLD), and event watchers dealing with the event |
71 | absolute timers with customised rescheduling (C<ev_periodic>), synchronous |
30 | loop mechanism itself (idle, prepare and check watchers). It also is quite |
72 | signals (C<ev_signal>), process status change events (C<ev_child>), and |
|
|
73 | event watchers dealing with the event loop mechanism itself (C<ev_idle>, |
|
|
74 | C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as |
|
|
75 | file watchers (C<ev_stat>) and even limited support for fork events |
|
|
76 | (C<ev_fork>). |
|
|
77 | |
|
|
78 | It also is quite fast (see this |
31 | fast (see this L<benchmark|http://libev.schmorp.de/bench.html> comparing |
79 | L<benchmark|http://libev.schmorp.de/bench.html> comparing it to libevent |
32 | it to libevent for example). |
80 | for example). |
33 | |
81 | |
34 | =head1 CONVENTIONS |
82 | =head1 CONVENTIONS |
35 | |
83 | |
36 | Libev is very configurable. In this manual the default configuration |
84 | Libev is very configurable. In this manual the default configuration will |
37 | will be described, which supports multiple event loops. For more info |
85 | be described, which supports multiple event loops. For more info about |
38 | about various configuration options please have a look at the file |
86 | 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 |
87 | this manual. If libev was configured without support for multiple event |
40 | support for multiple event loops, then all functions taking an initial |
88 | 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 *>) |
89 | (which is always of type C<struct ev_loop *>) will not have this argument. |
42 | will not have this argument. |
|
|
43 | |
90 | |
44 | =head1 TIME REPRESENTATION |
91 | =head1 TIME REPRESENTATION |
45 | |
92 | |
46 | Libev represents time as a single floating point number, representing the |
93 | Libev represents time as a single floating point number, representing the |
47 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
94 | (fractional) number of seconds since the (POSIX) epoch (somewhere near |
48 | the beginning of 1970, details are complicated, don't ask). This type is |
95 | 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 |
96 | 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 |
97 | to the C<double> type in C, and when you need to do any calculations on |
51 | it, you should treat it as such. |
98 | it, you should treat it as such. |
52 | |
99 | |
53 | |
|
|
54 | =head1 GLOBAL FUNCTIONS |
100 | =head1 GLOBAL FUNCTIONS |
55 | |
101 | |
56 | These functions can be called anytime, even before initialising the |
102 | These functions can be called anytime, even before initialising the |
57 | library in any way. |
103 | library in any way. |
58 | |
104 | |
… | |
… | |
77 | Usually, it's a good idea to terminate if the major versions mismatch, |
123 | Usually, it's a good idea to terminate if the major versions mismatch, |
78 | as this indicates an incompatible change. Minor versions are usually |
124 | as this indicates an incompatible change. Minor versions are usually |
79 | compatible to older versions, so a larger minor version alone is usually |
125 | compatible to older versions, so a larger minor version alone is usually |
80 | not a problem. |
126 | not a problem. |
81 | |
127 | |
82 | Example: make sure we haven't accidentally been linked against the wrong |
128 | Example: Make sure we haven't accidentally been linked against the wrong |
83 | version: |
129 | version. |
84 | |
130 | |
85 | assert (("libev version mismatch", |
131 | assert (("libev version mismatch", |
86 | ev_version_major () == EV_VERSION_MAJOR |
132 | ev_version_major () == EV_VERSION_MAJOR |
87 | && ev_version_minor () >= EV_VERSION_MINOR)); |
133 | && ev_version_minor () >= EV_VERSION_MINOR)); |
88 | |
134 | |
… | |
… | |
116 | C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for |
162 | C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for |
117 | recommended ones. |
163 | recommended ones. |
118 | |
164 | |
119 | See the description of C<ev_embed> watchers for more info. |
165 | See the description of C<ev_embed> watchers for more info. |
120 | |
166 | |
121 | =item ev_set_allocator (void *(*cb)(void *ptr, long size)) |
167 | =item ev_set_allocator (void *(*cb)(void *ptr, size_t size)) |
122 | |
168 | |
123 | Sets the allocation function to use (the prototype is similar to the |
169 | Sets the allocation function to use (the prototype and semantics are |
124 | realloc C function, the semantics are identical). It is used to allocate |
170 | identical to the realloc C function). It is used to allocate and free |
125 | and free memory (no surprises here). If it returns zero when memory |
171 | memory (no surprises here). If it returns zero when memory needs to be |
126 | needs to be allocated, the library might abort or take some potentially |
172 | allocated, the library might abort or take some potentially destructive |
127 | destructive action. The default is your system realloc function. |
173 | action. The default is your system realloc function. |
128 | |
174 | |
129 | You could override this function in high-availability programs to, say, |
175 | 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, |
176 | 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. |
177 | or even to sleep a while and retry until some memory is available. |
132 | |
178 | |
133 | Example: replace the libev allocator with one that waits a bit and then |
179 | Example: Replace the libev allocator with one that waits a bit and then |
134 | retries: better than mine). |
180 | retries). |
135 | |
181 | |
136 | static void * |
182 | static void * |
137 | persistent_realloc (void *ptr, long size) |
183 | persistent_realloc (void *ptr, size_t size) |
138 | { |
184 | { |
139 | for (;;) |
185 | for (;;) |
140 | { |
186 | { |
141 | void *newptr = realloc (ptr, size); |
187 | void *newptr = realloc (ptr, size); |
142 | |
188 | |
… | |
… | |
158 | callback is set, then libev will expect it to remedy the sitution, no |
204 | 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 |
205 | 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 |
206 | requested operation, or, if the condition doesn't go away, do bad stuff |
161 | (such as abort). |
207 | (such as abort). |
162 | |
208 | |
163 | Example: do the same thing as libev does internally: |
209 | Example: This is basically the same thing that libev does internally, too. |
164 | |
210 | |
165 | static void |
211 | static void |
166 | fatal_error (const char *msg) |
212 | fatal_error (const char *msg) |
167 | { |
213 | { |
168 | perror (msg); |
214 | perror (msg); |
… | |
… | |
314 | Similar to C<ev_default_loop>, but always creates a new event loop that is |
360 | 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 |
361 | 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 |
362 | 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). |
363 | undefined behaviour (or a failed assertion if assertions are enabled). |
318 | |
364 | |
319 | Example: try to create a event loop that uses epoll and nothing else. |
365 | Example: Try to create a event loop that uses epoll and nothing else. |
320 | |
366 | |
321 | struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
367 | struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV); |
322 | if (!epoller) |
368 | if (!epoller) |
323 | fatal ("no epoll found here, maybe it hides under your chair"); |
369 | fatal ("no epoll found here, maybe it hides under your chair"); |
324 | |
370 | |
… | |
… | |
423 | Signals and child watchers are implemented as I/O watchers, and will |
469 | Signals and child watchers are implemented as I/O watchers, and will |
424 | be handled here by queueing them when their watcher gets executed. |
470 | be handled here by queueing them when their watcher gets executed. |
425 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
471 | - If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK |
426 | were used, return, otherwise continue with step *. |
472 | were used, return, otherwise continue with step *. |
427 | |
473 | |
428 | Example: queue some jobs and then loop until no events are outsanding |
474 | Example: Queue some jobs and then loop until no events are outsanding |
429 | anymore. |
475 | anymore. |
430 | |
476 | |
431 | ... queue jobs here, make sure they register event watchers as long |
477 | ... 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..) |
478 | ... as they still have work to do (even an idle watcher will do..) |
433 | ev_loop (my_loop, 0); |
479 | ev_loop (my_loop, 0); |
… | |
… | |
453 | visible to the libev user and should not keep C<ev_loop> from exiting if |
499 | 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 |
500 | 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 |
501 | 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>. |
502 | libraries. Just remember to I<unref after start> and I<ref before stop>. |
457 | |
503 | |
458 | Example: create a signal watcher, but keep it from keeping C<ev_loop> |
504 | Example: Create a signal watcher, but keep it from keeping C<ev_loop> |
459 | running when nothing else is active. |
505 | running when nothing else is active. |
460 | |
506 | |
461 | struct dv_signal exitsig; |
507 | struct ev_signal exitsig; |
462 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
508 | ev_signal_init (&exitsig, sig_cb, SIGINT); |
463 | ev_signal_start (myloop, &exitsig); |
509 | ev_signal_start (loop, &exitsig); |
464 | evf_unref (myloop); |
510 | evf_unref (loop); |
465 | |
511 | |
466 | Example: for some weird reason, unregister the above signal handler again. |
512 | Example: For some weird reason, unregister the above signal handler again. |
467 | |
513 | |
468 | ev_ref (myloop); |
514 | ev_ref (loop); |
469 | ev_signal_stop (myloop, &exitsig); |
515 | ev_signal_stop (loop, &exitsig); |
470 | |
516 | |
471 | =back |
517 | =back |
472 | |
518 | |
473 | |
519 | |
474 | =head1 ANATOMY OF A WATCHER |
520 | =head1 ANATOMY OF A WATCHER |
… | |
… | |
544 | The signal specified in the C<ev_signal> watcher has been received by a thread. |
590 | The signal specified in the C<ev_signal> watcher has been received by a thread. |
545 | |
591 | |
546 | =item C<EV_CHILD> |
592 | =item C<EV_CHILD> |
547 | |
593 | |
548 | The pid specified in the C<ev_child> watcher has received a status change. |
594 | The pid specified in the C<ev_child> watcher has received a status change. |
|
|
595 | |
|
|
596 | =item C<EV_STAT> |
|
|
597 | |
|
|
598 | The path specified in the C<ev_stat> watcher changed its attributes somehow. |
549 | |
599 | |
550 | =item C<EV_IDLE> |
600 | =item C<EV_IDLE> |
551 | |
601 | |
552 | The C<ev_idle> watcher has determined that you have nothing better to do. |
602 | The C<ev_idle> watcher has determined that you have nothing better to do. |
553 | |
603 | |
… | |
… | |
561 | received events. Callbacks of both watcher types can start and stop as |
611 | received events. Callbacks of both watcher types can start and stop as |
562 | many watchers as they want, and all of them will be taken into account |
612 | many watchers as they want, and all of them will be taken into account |
563 | (for example, a C<ev_prepare> watcher might start an idle watcher to keep |
613 | (for example, a C<ev_prepare> watcher might start an idle watcher to keep |
564 | C<ev_loop> from blocking). |
614 | C<ev_loop> from blocking). |
565 | |
615 | |
|
|
616 | =item C<EV_EMBED> |
|
|
617 | |
|
|
618 | The embedded event loop specified in the C<ev_embed> watcher needs attention. |
|
|
619 | |
|
|
620 | =item C<EV_FORK> |
|
|
621 | |
|
|
622 | The event loop has been resumed in the child process after fork (see |
|
|
623 | C<ev_fork>). |
|
|
624 | |
566 | =item C<EV_ERROR> |
625 | =item C<EV_ERROR> |
567 | |
626 | |
568 | An unspecified error has occured, the watcher has been stopped. This might |
627 | An unspecified error has occured, the watcher has been stopped. This might |
569 | happen because the watcher could not be properly started because libev |
628 | happen because the watcher could not be properly started because libev |
570 | ran out of memory, a file descriptor was found to be closed or any other |
629 | ran out of memory, a file descriptor was found to be closed or any other |
… | |
… | |
644 | events but its callback has not yet been invoked). As long as a watcher |
703 | events but its callback has not yet been invoked). As long as a watcher |
645 | is pending (but not active) you must not call an init function on it (but |
704 | is pending (but not active) you must not call an init function on it (but |
646 | C<ev_TYPE_set> is safe) and you must make sure the watcher is available to |
705 | C<ev_TYPE_set> is safe) and you must make sure the watcher is available to |
647 | libev (e.g. you cnanot C<free ()> it). |
706 | libev (e.g. you cnanot C<free ()> it). |
648 | |
707 | |
649 | =item callback = ev_cb (ev_TYPE *watcher) |
708 | =item callback ev_cb (ev_TYPE *watcher) |
650 | |
709 | |
651 | Returns the callback currently set on the watcher. |
710 | Returns the callback currently set on the watcher. |
652 | |
711 | |
653 | =item ev_cb_set (ev_TYPE *watcher, callback) |
712 | =item ev_cb_set (ev_TYPE *watcher, callback) |
654 | |
713 | |
… | |
… | |
682 | { |
741 | { |
683 | struct my_io *w = (struct my_io *)w_; |
742 | struct my_io *w = (struct my_io *)w_; |
684 | ... |
743 | ... |
685 | } |
744 | } |
686 | |
745 | |
687 | More interesting and less C-conformant ways of catsing your callback type |
746 | More interesting and less C-conformant ways of casting your callback type |
688 | have been omitted.... |
747 | instead have been omitted. |
|
|
748 | |
|
|
749 | Another common scenario is having some data structure with multiple |
|
|
750 | watchers: |
|
|
751 | |
|
|
752 | struct my_biggy |
|
|
753 | { |
|
|
754 | int some_data; |
|
|
755 | ev_timer t1; |
|
|
756 | ev_timer t2; |
|
|
757 | } |
|
|
758 | |
|
|
759 | In this case getting the pointer to C<my_biggy> is a bit more complicated, |
|
|
760 | you need to use C<offsetof>: |
|
|
761 | |
|
|
762 | #include <stddef.h> |
|
|
763 | |
|
|
764 | static void |
|
|
765 | t1_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
766 | { |
|
|
767 | struct my_biggy big = (struct my_biggy * |
|
|
768 | (((char *)w) - offsetof (struct my_biggy, t1)); |
|
|
769 | } |
|
|
770 | |
|
|
771 | static void |
|
|
772 | t2_cb (EV_P_ struct ev_timer *w, int revents) |
|
|
773 | { |
|
|
774 | struct my_biggy big = (struct my_biggy * |
|
|
775 | (((char *)w) - offsetof (struct my_biggy, t2)); |
|
|
776 | } |
689 | |
777 | |
690 | |
778 | |
691 | =head1 WATCHER TYPES |
779 | =head1 WATCHER TYPES |
692 | |
780 | |
693 | This section describes each watcher in detail, but will not repeat |
781 | This section describes each watcher in detail, but will not repeat |
694 | information given in the last section. |
782 | information given in the last section. Any initialisation/set macros, |
|
|
783 | functions and members specific to the watcher type are explained. |
|
|
784 | |
|
|
785 | Members are additionally marked with either I<[read-only]>, meaning that, |
|
|
786 | while the watcher is active, you can look at the member and expect some |
|
|
787 | sensible content, but you must not modify it (you can modify it while the |
|
|
788 | watcher is stopped to your hearts content), or I<[read-write]>, which |
|
|
789 | means you can expect it to have some sensible content while the watcher |
|
|
790 | is active, but you can also modify it. Modifying it may not do something |
|
|
791 | sensible or take immediate effect (or do anything at all), but libev will |
|
|
792 | not crash or malfunction in any way. |
695 | |
793 | |
696 | |
794 | |
697 | =head2 C<ev_io> - is this file descriptor readable or writable? |
795 | =head2 C<ev_io> - is this file descriptor readable or writable? |
698 | |
796 | |
699 | I/O watchers check whether a file descriptor is readable or writable |
797 | I/O watchers check whether a file descriptor is readable or writable |
… | |
… | |
742 | |
840 | |
743 | Configures an C<ev_io> watcher. The C<fd> is the file descriptor to |
841 | Configures an C<ev_io> watcher. The C<fd> is the file descriptor to |
744 | rceeive events for and events is either C<EV_READ>, C<EV_WRITE> or |
842 | rceeive events for and events is either C<EV_READ>, C<EV_WRITE> or |
745 | C<EV_READ | EV_WRITE> to receive the given events. |
843 | C<EV_READ | EV_WRITE> to receive the given events. |
746 | |
844 | |
|
|
845 | =item int fd [read-only] |
|
|
846 | |
|
|
847 | The file descriptor being watched. |
|
|
848 | |
|
|
849 | =item int events [read-only] |
|
|
850 | |
|
|
851 | The events being watched. |
|
|
852 | |
747 | =back |
853 | =back |
748 | |
854 | |
749 | Example: call C<stdin_readable_cb> when STDIN_FILENO has become, well |
855 | Example: Call C<stdin_readable_cb> when STDIN_FILENO has become, well |
750 | readable, but only once. Since it is likely line-buffered, you could |
856 | readable, but only once. Since it is likely line-buffered, you could |
751 | attempt to read a whole line in the callback: |
857 | attempt to read a whole line in the callback. |
752 | |
858 | |
753 | static void |
859 | static void |
754 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
860 | stdin_readable_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
755 | { |
861 | { |
756 | ev_io_stop (loop, w); |
862 | ev_io_stop (loop, w); |
… | |
… | |
814 | |
920 | |
815 | If the timer is repeating, either start it if necessary (with the repeat |
921 | If the timer is repeating, either start it if necessary (with the repeat |
816 | value), or reset the running timer to the repeat value. |
922 | value), or reset the running timer to the repeat value. |
817 | |
923 | |
818 | This sounds a bit complicated, but here is a useful and typical |
924 | This sounds a bit complicated, but here is a useful and typical |
819 | example: Imagine you have a tcp connection and you want a so-called idle |
925 | example: Imagine you have a tcp connection and you want a so-called |
820 | timeout, that is, you want to be called when there have been, say, 60 |
926 | idle timeout, that is, you want to be called when there have been, |
821 | seconds of inactivity on the socket. The easiest way to do this is to |
927 | say, 60 seconds of inactivity on the socket. The easiest way to do |
822 | configure an C<ev_timer> with after=repeat=60 and calling ev_timer_again each |
928 | this is to configure an C<ev_timer> with C<after>=C<repeat>=C<60> and calling |
823 | time you successfully read or write some data. If you go into an idle |
929 | C<ev_timer_again> each time you successfully read or write some data. If |
824 | state where you do not expect data to travel on the socket, you can stop |
930 | you go into an idle state where you do not expect data to travel on the |
825 | the timer, and again will automatically restart it if need be. |
931 | socket, you can stop the timer, and again will automatically restart it if |
|
|
932 | need be. |
|
|
933 | |
|
|
934 | You can also ignore the C<after> value and C<ev_timer_start> altogether |
|
|
935 | and only ever use the C<repeat> value: |
|
|
936 | |
|
|
937 | ev_timer_init (timer, callback, 0., 5.); |
|
|
938 | ev_timer_again (loop, timer); |
|
|
939 | ... |
|
|
940 | timer->again = 17.; |
|
|
941 | ev_timer_again (loop, timer); |
|
|
942 | ... |
|
|
943 | timer->again = 10.; |
|
|
944 | ev_timer_again (loop, timer); |
|
|
945 | |
|
|
946 | This is more efficient then stopping/starting the timer eahc time you want |
|
|
947 | to modify its timeout value. |
|
|
948 | |
|
|
949 | =item ev_tstamp repeat [read-write] |
|
|
950 | |
|
|
951 | The current C<repeat> value. Will be used each time the watcher times out |
|
|
952 | or C<ev_timer_again> is called and determines the next timeout (if any), |
|
|
953 | which is also when any modifications are taken into account. |
826 | |
954 | |
827 | =back |
955 | =back |
828 | |
956 | |
829 | Example: create a timer that fires after 60 seconds. |
957 | Example: Create a timer that fires after 60 seconds. |
830 | |
958 | |
831 | static void |
959 | static void |
832 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
960 | one_minute_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
833 | { |
961 | { |
834 | .. one minute over, w is actually stopped right here |
962 | .. one minute over, w is actually stopped right here |
… | |
… | |
836 | |
964 | |
837 | struct ev_timer mytimer; |
965 | struct ev_timer mytimer; |
838 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
966 | ev_timer_init (&mytimer, one_minute_cb, 60., 0.); |
839 | ev_timer_start (loop, &mytimer); |
967 | ev_timer_start (loop, &mytimer); |
840 | |
968 | |
841 | Example: create a timeout timer that times out after 10 seconds of |
969 | Example: Create a timeout timer that times out after 10 seconds of |
842 | inactivity. |
970 | inactivity. |
843 | |
971 | |
844 | static void |
972 | static void |
845 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
973 | timeout_cb (struct ev_loop *loop, struct ev_timer *w, int revents) |
846 | { |
974 | { |
… | |
… | |
957 | Simply stops and restarts the periodic watcher again. This is only useful |
1085 | Simply stops and restarts the periodic watcher again. This is only useful |
958 | when you changed some parameters or the reschedule callback would return |
1086 | when you changed some parameters or the reschedule callback would return |
959 | a different time than the last time it was called (e.g. in a crond like |
1087 | a different time than the last time it was called (e.g. in a crond like |
960 | program when the crontabs have changed). |
1088 | program when the crontabs have changed). |
961 | |
1089 | |
|
|
1090 | =item ev_tstamp interval [read-write] |
|
|
1091 | |
|
|
1092 | The current interval value. Can be modified any time, but changes only |
|
|
1093 | take effect when the periodic timer fires or C<ev_periodic_again> is being |
|
|
1094 | called. |
|
|
1095 | |
|
|
1096 | =item ev_tstamp (*reschedule_cb)(struct ev_periodic *w, ev_tstamp now) [read-write] |
|
|
1097 | |
|
|
1098 | The current reschedule callback, or C<0>, if this functionality is |
|
|
1099 | switched off. Can be changed any time, but changes only take effect when |
|
|
1100 | the periodic timer fires or C<ev_periodic_again> is being called. |
|
|
1101 | |
962 | =back |
1102 | =back |
963 | |
1103 | |
964 | Example: call a callback every hour, or, more precisely, whenever the |
1104 | Example: Call a callback every hour, or, more precisely, whenever the |
965 | system clock is divisible by 3600. The callback invocation times have |
1105 | system clock is divisible by 3600. The callback invocation times have |
966 | potentially a lot of jittering, but good long-term stability. |
1106 | potentially a lot of jittering, but good long-term stability. |
967 | |
1107 | |
968 | static void |
1108 | static void |
969 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
1109 | clock_cb (struct ev_loop *loop, struct ev_io *w, int revents) |
… | |
… | |
973 | |
1113 | |
974 | struct ev_periodic hourly_tick; |
1114 | struct ev_periodic hourly_tick; |
975 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
1115 | ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0); |
976 | ev_periodic_start (loop, &hourly_tick); |
1116 | ev_periodic_start (loop, &hourly_tick); |
977 | |
1117 | |
978 | Example: the same as above, but use a reschedule callback to do it: |
1118 | Example: The same as above, but use a reschedule callback to do it: |
979 | |
1119 | |
980 | #include <math.h> |
1120 | #include <math.h> |
981 | |
1121 | |
982 | static ev_tstamp |
1122 | static ev_tstamp |
983 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
1123 | my_scheduler_cb (struct ev_periodic *w, ev_tstamp now) |
… | |
… | |
985 | return fmod (now, 3600.) + 3600.; |
1125 | return fmod (now, 3600.) + 3600.; |
986 | } |
1126 | } |
987 | |
1127 | |
988 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
1128 | ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb); |
989 | |
1129 | |
990 | Example: call a callback every hour, starting now: |
1130 | Example: Call a callback every hour, starting now: |
991 | |
1131 | |
992 | struct ev_periodic hourly_tick; |
1132 | struct ev_periodic hourly_tick; |
993 | ev_periodic_init (&hourly_tick, clock_cb, |
1133 | ev_periodic_init (&hourly_tick, clock_cb, |
994 | fmod (ev_now (loop), 3600.), 3600., 0); |
1134 | fmod (ev_now (loop), 3600.), 3600., 0); |
995 | ev_periodic_start (loop, &hourly_tick); |
1135 | ev_periodic_start (loop, &hourly_tick); |
… | |
… | |
1016 | =item ev_signal_set (ev_signal *, int signum) |
1156 | =item ev_signal_set (ev_signal *, int signum) |
1017 | |
1157 | |
1018 | Configures the watcher to trigger on the given signal number (usually one |
1158 | Configures the watcher to trigger on the given signal number (usually one |
1019 | of the C<SIGxxx> constants). |
1159 | of the C<SIGxxx> constants). |
1020 | |
1160 | |
|
|
1161 | =item int signum [read-only] |
|
|
1162 | |
|
|
1163 | The signal the watcher watches out for. |
|
|
1164 | |
1021 | =back |
1165 | =back |
1022 | |
1166 | |
1023 | |
1167 | |
1024 | =head2 C<ev_child> - watch out for process status changes |
1168 | =head2 C<ev_child> - watch out for process status changes |
1025 | |
1169 | |
… | |
… | |
1037 | at the C<rstatus> member of the C<ev_child> watcher structure to see |
1181 | at the C<rstatus> member of the C<ev_child> watcher structure to see |
1038 | the status word (use the macros from C<sys/wait.h> and see your systems |
1182 | the status word (use the macros from C<sys/wait.h> and see your systems |
1039 | C<waitpid> documentation). The C<rpid> member contains the pid of the |
1183 | C<waitpid> documentation). The C<rpid> member contains the pid of the |
1040 | process causing the status change. |
1184 | process causing the status change. |
1041 | |
1185 | |
|
|
1186 | =item int pid [read-only] |
|
|
1187 | |
|
|
1188 | The process id this watcher watches out for, or C<0>, meaning any process id. |
|
|
1189 | |
|
|
1190 | =item int rpid [read-write] |
|
|
1191 | |
|
|
1192 | The process id that detected a status change. |
|
|
1193 | |
|
|
1194 | =item int rstatus [read-write] |
|
|
1195 | |
|
|
1196 | The process exit/trace status caused by C<rpid> (see your systems |
|
|
1197 | C<waitpid> and C<sys/wait.h> documentation for details). |
|
|
1198 | |
1042 | =back |
1199 | =back |
1043 | |
1200 | |
1044 | Example: try to exit cleanly on SIGINT and SIGTERM. |
1201 | Example: Try to exit cleanly on SIGINT and SIGTERM. |
1045 | |
1202 | |
1046 | static void |
1203 | static void |
1047 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1204 | sigint_cb (struct ev_loop *loop, struct ev_signal *w, int revents) |
1048 | { |
1205 | { |
1049 | ev_unloop (loop, EVUNLOOP_ALL); |
1206 | ev_unloop (loop, EVUNLOOP_ALL); |
1050 | } |
1207 | } |
1051 | |
1208 | |
1052 | struct ev_signal signal_watcher; |
1209 | struct ev_signal signal_watcher; |
1053 | ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1210 | ev_signal_init (&signal_watcher, sigint_cb, SIGINT); |
1054 | ev_signal_start (loop, &sigint_cb); |
1211 | ev_signal_start (loop, &sigint_cb); |
|
|
1212 | |
|
|
1213 | |
|
|
1214 | =head2 C<ev_stat> - did the file attributes just change? |
|
|
1215 | |
|
|
1216 | This watches a filesystem path for attribute changes. That is, it calls |
|
|
1217 | C<stat> regularly (or when the OS says it changed) and sees if it changed |
|
|
1218 | compared to the last time, invoking the callback if it did. |
|
|
1219 | |
|
|
1220 | The path does not need to exist: changing from "path exists" to "path does |
|
|
1221 | not exist" is a status change like any other. The condition "path does |
|
|
1222 | not exist" is signified by the C<st_nlink> field being zero (which is |
|
|
1223 | otherwise always forced to be at least one) and all the other fields of |
|
|
1224 | the stat buffer having unspecified contents. |
|
|
1225 | |
|
|
1226 | Since there is no standard to do this, the portable implementation simply |
|
|
1227 | calls C<stat (2)> regularly on the path to see if it changed somehow. You |
|
|
1228 | can specify a recommended polling interval for this case. If you specify |
|
|
1229 | a polling interval of C<0> (highly recommended!) then a I<suitable, |
|
|
1230 | unspecified default> value will be used (which you can expect to be around |
|
|
1231 | five seconds, although this might change dynamically). Libev will also |
|
|
1232 | impose a minimum interval which is currently around C<0.1>, but thats |
|
|
1233 | usually overkill. |
|
|
1234 | |
|
|
1235 | This watcher type is not meant for massive numbers of stat watchers, |
|
|
1236 | as even with OS-supported change notifications, this can be |
|
|
1237 | resource-intensive. |
|
|
1238 | |
|
|
1239 | At the time of this writing, only the Linux inotify interface is |
|
|
1240 | implemented (implementing kqueue support is left as an exercise for the |
|
|
1241 | reader). Inotify will be used to give hints only and should not change the |
|
|
1242 | semantics of C<ev_stat> watchers, which means that libev sometimes needs |
|
|
1243 | to fall back to regular polling again even with inotify, but changes are |
|
|
1244 | usually detected immediately, and if the file exists there will be no |
|
|
1245 | polling. |
|
|
1246 | |
|
|
1247 | =over 4 |
|
|
1248 | |
|
|
1249 | =item ev_stat_init (ev_stat *, callback, const char *path, ev_tstamp interval) |
|
|
1250 | |
|
|
1251 | =item ev_stat_set (ev_stat *, const char *path, ev_tstamp interval) |
|
|
1252 | |
|
|
1253 | Configures the watcher to wait for status changes of the given |
|
|
1254 | C<path>. The C<interval> is a hint on how quickly a change is expected to |
|
|
1255 | be detected and should normally be specified as C<0> to let libev choose |
|
|
1256 | a suitable value. The memory pointed to by C<path> must point to the same |
|
|
1257 | path for as long as the watcher is active. |
|
|
1258 | |
|
|
1259 | The callback will be receive C<EV_STAT> when a change was detected, |
|
|
1260 | relative to the attributes at the time the watcher was started (or the |
|
|
1261 | last change was detected). |
|
|
1262 | |
|
|
1263 | =item ev_stat_stat (ev_stat *) |
|
|
1264 | |
|
|
1265 | Updates the stat buffer immediately with new values. If you change the |
|
|
1266 | watched path in your callback, you could call this fucntion to avoid |
|
|
1267 | detecting this change (while introducing a race condition). Can also be |
|
|
1268 | useful simply to find out the new values. |
|
|
1269 | |
|
|
1270 | =item ev_statdata attr [read-only] |
|
|
1271 | |
|
|
1272 | The most-recently detected attributes of the file. Although the type is of |
|
|
1273 | C<ev_statdata>, this is usually the (or one of the) C<struct stat> types |
|
|
1274 | suitable for your system. If the C<st_nlink> member is C<0>, then there |
|
|
1275 | was some error while C<stat>ing the file. |
|
|
1276 | |
|
|
1277 | =item ev_statdata prev [read-only] |
|
|
1278 | |
|
|
1279 | The previous attributes of the file. The callback gets invoked whenever |
|
|
1280 | C<prev> != C<attr>. |
|
|
1281 | |
|
|
1282 | =item ev_tstamp interval [read-only] |
|
|
1283 | |
|
|
1284 | The specified interval. |
|
|
1285 | |
|
|
1286 | =item const char *path [read-only] |
|
|
1287 | |
|
|
1288 | The filesystem path that is being watched. |
|
|
1289 | |
|
|
1290 | =back |
|
|
1291 | |
|
|
1292 | Example: Watch C</etc/passwd> for attribute changes. |
|
|
1293 | |
|
|
1294 | static void |
|
|
1295 | passwd_cb (struct ev_loop *loop, ev_stat *w, int revents) |
|
|
1296 | { |
|
|
1297 | /* /etc/passwd changed in some way */ |
|
|
1298 | if (w->attr.st_nlink) |
|
|
1299 | { |
|
|
1300 | printf ("passwd current size %ld\n", (long)w->attr.st_size); |
|
|
1301 | printf ("passwd current atime %ld\n", (long)w->attr.st_mtime); |
|
|
1302 | printf ("passwd current mtime %ld\n", (long)w->attr.st_mtime); |
|
|
1303 | } |
|
|
1304 | else |
|
|
1305 | /* you shalt not abuse printf for puts */ |
|
|
1306 | puts ("wow, /etc/passwd is not there, expect problems. " |
|
|
1307 | "if this is windows, they already arrived\n"); |
|
|
1308 | } |
|
|
1309 | |
|
|
1310 | ... |
|
|
1311 | ev_stat passwd; |
|
|
1312 | |
|
|
1313 | ev_stat_init (&passwd, passwd_cb, "/etc/passwd"); |
|
|
1314 | ev_stat_start (loop, &passwd); |
1055 | |
1315 | |
1056 | |
1316 | |
1057 | =head2 C<ev_idle> - when you've got nothing better to do... |
1317 | =head2 C<ev_idle> - when you've got nothing better to do... |
1058 | |
1318 | |
1059 | Idle watchers trigger events when there are no other events are pending |
1319 | Idle watchers trigger events when there are no other events are pending |
… | |
… | |
1080 | kind. There is a C<ev_idle_set> macro, but using it is utterly pointless, |
1340 | kind. There is a C<ev_idle_set> macro, but using it is utterly pointless, |
1081 | believe me. |
1341 | believe me. |
1082 | |
1342 | |
1083 | =back |
1343 | =back |
1084 | |
1344 | |
1085 | Example: dynamically allocate an C<ev_idle>, start it, and in the |
1345 | Example: Dynamically allocate an C<ev_idle> watcher, start it, and in the |
1086 | callback, free it. Alos, use no error checking, as usual. |
1346 | callback, free it. Also, use no error checking, as usual. |
1087 | |
1347 | |
1088 | static void |
1348 | static void |
1089 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1349 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1090 | { |
1350 | { |
1091 | free (w); |
1351 | free (w); |
… | |
… | |
1160 | |
1420 | |
1161 | static void |
1421 | static void |
1162 | io_cb (ev_loop *loop, ev_io *w, int revents) |
1422 | io_cb (ev_loop *loop, ev_io *w, int revents) |
1163 | { |
1423 | { |
1164 | // set the relevant poll flags |
1424 | // set the relevant poll flags |
|
|
1425 | // could also call adns_processreadable etc. here |
1165 | struct pollfd *fd = (struct pollfd *)w->data; |
1426 | struct pollfd *fd = (struct pollfd *)w->data; |
1166 | if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
1427 | if (revents & EV_READ ) fd->revents |= fd->events & POLLIN; |
1167 | if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
1428 | if (revents & EV_WRITE) fd->revents |= fd->events & POLLOUT; |
1168 | } |
1429 | } |
1169 | |
1430 | |
… | |
… | |
1291 | |
1552 | |
1292 | Make a single, non-blocking sweep over the embedded loop. This works |
1553 | Make a single, non-blocking sweep over the embedded loop. This works |
1293 | similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most |
1554 | similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most |
1294 | apropriate way for embedded loops. |
1555 | apropriate way for embedded loops. |
1295 | |
1556 | |
|
|
1557 | =item struct ev_loop *loop [read-only] |
|
|
1558 | |
|
|
1559 | The embedded event loop. |
|
|
1560 | |
|
|
1561 | =back |
|
|
1562 | |
|
|
1563 | |
|
|
1564 | =head2 C<ev_fork> - the audacity to resume the event loop after a fork |
|
|
1565 | |
|
|
1566 | Fork watchers are called when a C<fork ()> was detected (usually because |
|
|
1567 | whoever is a good citizen cared to tell libev about it by calling |
|
|
1568 | C<ev_default_fork> or C<ev_loop_fork>). The invocation is done before the |
|
|
1569 | event loop blocks next and before C<ev_check> watchers are being called, |
|
|
1570 | and only in the child after the fork. If whoever good citizen calling |
|
|
1571 | C<ev_default_fork> cheats and calls it in the wrong process, the fork |
|
|
1572 | handlers will be invoked, too, of course. |
|
|
1573 | |
|
|
1574 | =over 4 |
|
|
1575 | |
|
|
1576 | =item ev_fork_init (ev_signal *, callback) |
|
|
1577 | |
|
|
1578 | Initialises and configures the fork watcher - it has no parameters of any |
|
|
1579 | kind. There is a C<ev_fork_set> macro, but using it is utterly pointless, |
|
|
1580 | believe me. |
|
|
1581 | |
1296 | =back |
1582 | =back |
1297 | |
1583 | |
1298 | |
1584 | |
1299 | =head1 OTHER FUNCTIONS |
1585 | =head1 OTHER FUNCTIONS |
1300 | |
1586 | |
… | |
… | |
1462 | |
1748 | |
1463 | =item w->sweep () C<ev::embed> only |
1749 | =item w->sweep () C<ev::embed> only |
1464 | |
1750 | |
1465 | Invokes C<ev_embed_sweep>. |
1751 | Invokes C<ev_embed_sweep>. |
1466 | |
1752 | |
|
|
1753 | =item w->update () C<ev::stat> only |
|
|
1754 | |
|
|
1755 | Invokes C<ev_stat_stat>. |
|
|
1756 | |
1467 | =back |
1757 | =back |
1468 | |
1758 | |
1469 | =back |
1759 | =back |
1470 | |
1760 | |
1471 | Example: Define a class with an IO and idle watcher, start one of them in |
1761 | Example: Define a class with an IO and idle watcher, start one of them in |
… | |
… | |
1483 | : io (this, &myclass::io_cb), |
1773 | : io (this, &myclass::io_cb), |
1484 | idle (this, &myclass::idle_cb) |
1774 | idle (this, &myclass::idle_cb) |
1485 | { |
1775 | { |
1486 | io.start (fd, ev::READ); |
1776 | io.start (fd, ev::READ); |
1487 | } |
1777 | } |
|
|
1778 | |
|
|
1779 | |
|
|
1780 | =head1 MACRO MAGIC |
|
|
1781 | |
|
|
1782 | Libev can be compiled with a variety of options, the most fundemantal is |
|
|
1783 | C<EV_MULTIPLICITY>. This option determines wether (most) functions and |
|
|
1784 | callbacks have an initial C<struct ev_loop *> argument. |
|
|
1785 | |
|
|
1786 | To make it easier to write programs that cope with either variant, the |
|
|
1787 | following macros are defined: |
|
|
1788 | |
|
|
1789 | =over 4 |
|
|
1790 | |
|
|
1791 | =item C<EV_A>, C<EV_A_> |
|
|
1792 | |
|
|
1793 | This provides the loop I<argument> for functions, if one is required ("ev |
|
|
1794 | loop argument"). The C<EV_A> form is used when this is the sole argument, |
|
|
1795 | C<EV_A_> is used when other arguments are following. Example: |
|
|
1796 | |
|
|
1797 | ev_unref (EV_A); |
|
|
1798 | ev_timer_add (EV_A_ watcher); |
|
|
1799 | ev_loop (EV_A_ 0); |
|
|
1800 | |
|
|
1801 | It assumes the variable C<loop> of type C<struct ev_loop *> is in scope, |
|
|
1802 | which is often provided by the following macro. |
|
|
1803 | |
|
|
1804 | =item C<EV_P>, C<EV_P_> |
|
|
1805 | |
|
|
1806 | This provides the loop I<parameter> for functions, if one is required ("ev |
|
|
1807 | loop parameter"). The C<EV_P> form is used when this is the sole parameter, |
|
|
1808 | C<EV_P_> is used when other parameters are following. Example: |
|
|
1809 | |
|
|
1810 | // this is how ev_unref is being declared |
|
|
1811 | static void ev_unref (EV_P); |
|
|
1812 | |
|
|
1813 | // this is how you can declare your typical callback |
|
|
1814 | static void cb (EV_P_ ev_timer *w, int revents) |
|
|
1815 | |
|
|
1816 | It declares a parameter C<loop> of type C<struct ev_loop *>, quite |
|
|
1817 | suitable for use with C<EV_A>. |
|
|
1818 | |
|
|
1819 | =item C<EV_DEFAULT>, C<EV_DEFAULT_> |
|
|
1820 | |
|
|
1821 | Similar to the other two macros, this gives you the value of the default |
|
|
1822 | loop, if multiple loops are supported ("ev loop default"). |
|
|
1823 | |
|
|
1824 | =back |
|
|
1825 | |
|
|
1826 | Example: Declare and initialise a check watcher, working regardless of |
|
|
1827 | wether multiple loops are supported or not. |
|
|
1828 | |
|
|
1829 | static void |
|
|
1830 | check_cb (EV_P_ ev_timer *w, int revents) |
|
|
1831 | { |
|
|
1832 | ev_check_stop (EV_A_ w); |
|
|
1833 | } |
|
|
1834 | |
|
|
1835 | ev_check check; |
|
|
1836 | ev_check_init (&check, check_cb); |
|
|
1837 | ev_check_start (EV_DEFAULT_ &check); |
|
|
1838 | ev_loop (EV_DEFAULT_ 0); |
|
|
1839 | |
1488 | |
1840 | |
1489 | =head1 EMBEDDING |
1841 | =head1 EMBEDDING |
1490 | |
1842 | |
1491 | Libev can (and often is) directly embedded into host |
1843 | Libev can (and often is) directly embedded into host |
1492 | applications. Examples of applications that embed it include the Deliantra |
1844 | applications. Examples of applications that embed it include the Deliantra |
… | |
… | |
1667 | |
2019 | |
1668 | =item EV_USE_DEVPOLL |
2020 | =item EV_USE_DEVPOLL |
1669 | |
2021 | |
1670 | reserved for future expansion, works like the USE symbols above. |
2022 | reserved for future expansion, works like the USE symbols above. |
1671 | |
2023 | |
|
|
2024 | =item EV_USE_INOTIFY |
|
|
2025 | |
|
|
2026 | If defined to be C<1>, libev will compile in support for the Linux inotify |
|
|
2027 | interface to speed up C<ev_stat> watchers. Its actual availability will |
|
|
2028 | be detected at runtime. |
|
|
2029 | |
1672 | =item EV_H |
2030 | =item EV_H |
1673 | |
2031 | |
1674 | The name of the F<ev.h> header file used to include it. The default if |
2032 | The name of the F<ev.h> header file used to include it. The default if |
1675 | undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This |
2033 | undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This |
1676 | can be used to virtually rename the F<ev.h> header file in case of conflicts. |
2034 | can be used to virtually rename the F<ev.h> header file in case of conflicts. |
… | |
… | |
1699 | will have the C<struct ev_loop *> as first argument, and you can create |
2057 | will have the C<struct ev_loop *> as first argument, and you can create |
1700 | additional independent event loops. Otherwise there will be no support |
2058 | additional independent event loops. Otherwise there will be no support |
1701 | for multiple event loops and there is no first event loop pointer |
2059 | for multiple event loops and there is no first event loop pointer |
1702 | argument. Instead, all functions act on the single default loop. |
2060 | argument. Instead, all functions act on the single default loop. |
1703 | |
2061 | |
1704 | =item EV_PERIODICS |
2062 | =item EV_PERIODIC_ENABLE |
1705 | |
2063 | |
1706 | If undefined or defined to be C<1>, then periodic timers are supported, |
2064 | If undefined or defined to be C<1>, then periodic timers are supported. If |
1707 | otherwise not. This saves a few kb of code. |
2065 | defined to be C<0>, then they are not. Disabling them saves a few kB of |
|
|
2066 | code. |
|
|
2067 | |
|
|
2068 | =item EV_EMBED_ENABLE |
|
|
2069 | |
|
|
2070 | If undefined or defined to be C<1>, then embed watchers are supported. If |
|
|
2071 | defined to be C<0>, then they are not. |
|
|
2072 | |
|
|
2073 | =item EV_STAT_ENABLE |
|
|
2074 | |
|
|
2075 | If undefined or defined to be C<1>, then stat watchers are supported. If |
|
|
2076 | defined to be C<0>, then they are not. |
|
|
2077 | |
|
|
2078 | =item EV_FORK_ENABLE |
|
|
2079 | |
|
|
2080 | If undefined or defined to be C<1>, then fork watchers are supported. If |
|
|
2081 | defined to be C<0>, then they are not. |
|
|
2082 | |
|
|
2083 | =item EV_MINIMAL |
|
|
2084 | |
|
|
2085 | If you need to shave off some kilobytes of code at the expense of some |
|
|
2086 | speed, define this symbol to C<1>. Currently only used for gcc to override |
|
|
2087 | some inlining decisions, saves roughly 30% codesize of amd64. |
|
|
2088 | |
|
|
2089 | =item EV_PID_HASHSIZE |
|
|
2090 | |
|
|
2091 | C<ev_child> watchers use a small hash table to distribute workload by |
|
|
2092 | pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more |
|
|
2093 | than enough. If you need to manage thousands of children you might want to |
|
|
2094 | increase this value (I<must> be a power of two). |
|
|
2095 | |
|
|
2096 | =item EV_INOTIFY_HASHSIZE |
|
|
2097 | |
|
|
2098 | C<ev_staz> watchers use a small hash table to distribute workload by |
|
|
2099 | inotify watch id. The default size is C<16> (or C<1> with C<EV_MINIMAL>), |
|
|
2100 | usually more than enough. If you need to manage thousands of C<ev_stat> |
|
|
2101 | watchers you might want to increase this value (I<must> be a power of |
|
|
2102 | two). |
1708 | |
2103 | |
1709 | =item EV_COMMON |
2104 | =item EV_COMMON |
1710 | |
2105 | |
1711 | By default, all watchers have a C<void *data> member. By redefining |
2106 | By default, all watchers have a C<void *data> member. By redefining |
1712 | this macro to a something else you can include more and other types of |
2107 | this macro to a something else you can include more and other types of |
… | |
… | |
1755 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
2150 | And a F<ev_cpp.C> implementation file that contains libev proper and is compiled: |
1756 | |
2151 | |
1757 | #include "ev_cpp.h" |
2152 | #include "ev_cpp.h" |
1758 | #include "ev.c" |
2153 | #include "ev.c" |
1759 | |
2154 | |
|
|
2155 | |
|
|
2156 | =head1 COMPLEXITIES |
|
|
2157 | |
|
|
2158 | In this section the complexities of (many of) the algorithms used inside |
|
|
2159 | libev will be explained. For complexity discussions about backends see the |
|
|
2160 | documentation for C<ev_default_init>. |
|
|
2161 | |
|
|
2162 | =over 4 |
|
|
2163 | |
|
|
2164 | =item Starting and stopping timer/periodic watchers: O(log skipped_other_timers) |
|
|
2165 | |
|
|
2166 | =item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers) |
|
|
2167 | |
|
|
2168 | =item Starting io/check/prepare/idle/signal/child watchers: O(1) |
|
|
2169 | |
|
|
2170 | =item Stopping check/prepare/idle watchers: O(1) |
|
|
2171 | |
|
|
2172 | =item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE)) |
|
|
2173 | |
|
|
2174 | =item Finding the next timer per loop iteration: O(1) |
|
|
2175 | |
|
|
2176 | =item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd) |
|
|
2177 | |
|
|
2178 | =item Activating one watcher: O(1) |
|
|
2179 | |
|
|
2180 | =back |
|
|
2181 | |
|
|
2182 | |
1760 | =head1 AUTHOR |
2183 | =head1 AUTHOR |
1761 | |
2184 | |
1762 | Marc Lehmann <libev@schmorp.de>. |
2185 | Marc Lehmann <libev@schmorp.de>. |
1763 | |
2186 | |