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135 | .IX Title "LIBEV 3" |
135 | .IX Title "LIBEV 3" |
136 | .TH LIBEV 3 "2017-06-21" "libev-4.24" "libev - high performance full featured event loop" |
136 | .TH LIBEV 3 "2019-06-23" "libev-4.25" "libev - high performance full featured event loop" |
137 | .\" For nroff, turn off justification. Always turn off hyphenation; it makes |
137 | .\" For nroff, turn off justification. Always turn off hyphenation; it makes |
138 | .\" way too many mistakes in technical documents. |
138 | .\" way too many mistakes in technical documents. |
139 | .if n .ad l |
139 | .if n .ad l |
140 | .nh |
140 | .nh |
141 | .SH "NAME" |
141 | .SH "NAME" |
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240 | watchers\fR, which are relatively small C structures you initialise with the |
240 | watchers\fR, which are relatively small C structures you initialise with the |
241 | details of the event, and then hand it over to libev by \fIstarting\fR the |
241 | details of the event, and then hand it over to libev by \fIstarting\fR the |
242 | watcher. |
242 | watcher. |
243 | .SS "\s-1FEATURES\s0" |
243 | .SS "\s-1FEATURES\s0" |
244 | .IX Subsection "FEATURES" |
244 | .IX Subsection "FEATURES" |
245 | Libev supports \f(CW\*(C`select\*(C'\fR, \f(CW\*(C`poll\*(C'\fR, the Linux-specific \f(CW\*(C`epoll\*(C'\fR, the |
245 | Libev supports \f(CW\*(C`select\*(C'\fR, \f(CW\*(C`poll\*(C'\fR, the Linux-specific aio and \f(CW\*(C`epoll\*(C'\fR |
246 | BSD-specific \f(CW\*(C`kqueue\*(C'\fR and the Solaris-specific event port mechanisms |
246 | interfaces, the BSD-specific \f(CW\*(C`kqueue\*(C'\fR and the Solaris-specific event port |
247 | for file descriptor events (\f(CW\*(C`ev_io\*(C'\fR), the Linux \f(CW\*(C`inotify\*(C'\fR interface |
247 | mechanisms for file descriptor events (\f(CW\*(C`ev_io\*(C'\fR), the Linux \f(CW\*(C`inotify\*(C'\fR |
248 | (for \f(CW\*(C`ev_stat\*(C'\fR), Linux eventfd/signalfd (for faster and cleaner |
248 | interface (for \f(CW\*(C`ev_stat\*(C'\fR), Linux eventfd/signalfd (for faster and cleaner |
249 | inter-thread wakeup (\f(CW\*(C`ev_async\*(C'\fR)/signal handling (\f(CW\*(C`ev_signal\*(C'\fR)) relative |
249 | inter-thread wakeup (\f(CW\*(C`ev_async\*(C'\fR)/signal handling (\f(CW\*(C`ev_signal\*(C'\fR)) relative |
250 | timers (\f(CW\*(C`ev_timer\*(C'\fR), absolute timers with customised rescheduling |
250 | timers (\f(CW\*(C`ev_timer\*(C'\fR), absolute timers with customised rescheduling |
251 | (\f(CW\*(C`ev_periodic\*(C'\fR), synchronous signals (\f(CW\*(C`ev_signal\*(C'\fR), process status |
251 | (\f(CW\*(C`ev_periodic\*(C'\fR), synchronous signals (\f(CW\*(C`ev_signal\*(C'\fR), process status |
252 | change events (\f(CW\*(C`ev_child\*(C'\fR), and event watchers dealing with the event |
252 | change events (\f(CW\*(C`ev_child\*(C'\fR), and event watchers dealing with the event |
253 | loop mechanism itself (\f(CW\*(C`ev_idle\*(C'\fR, \f(CW\*(C`ev_embed\*(C'\fR, \f(CW\*(C`ev_prepare\*(C'\fR and |
253 | loop mechanism itself (\f(CW\*(C`ev_idle\*(C'\fR, \f(CW\*(C`ev_embed\*(C'\fR, \f(CW\*(C`ev_prepare\*(C'\fR and |
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392 | .Sp |
392 | .Sp |
393 | You could override this function in high-availability programs to, say, |
393 | You could override this function in high-availability programs to, say, |
394 | free some memory if it cannot allocate memory, to use a special allocator, |
394 | free some memory if it cannot allocate memory, to use a special allocator, |
395 | or even to sleep a while and retry until some memory is available. |
395 | or even to sleep a while and retry until some memory is available. |
396 | .Sp |
396 | .Sp |
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397 | Example: The following is the \f(CW\*(C`realloc\*(C'\fR function that libev itself uses |
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398 | which should work with \f(CW\*(C`realloc\*(C'\fR and \f(CW\*(C`free\*(C'\fR functions of all kinds and |
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399 | is probably a good basis for your own implementation. |
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400 | .Sp |
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401 | .Vb 5 |
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402 | \& static void * |
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403 | \& ev_realloc_emul (void *ptr, long size) EV_NOEXCEPT |
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404 | \& { |
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405 | \& if (size) |
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406 | \& return realloc (ptr, size); |
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407 | \& |
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408 | \& free (ptr); |
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409 | \& return 0; |
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410 | \& } |
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411 | .Ve |
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412 | .Sp |
397 | Example: Replace the libev allocator with one that waits a bit and then |
413 | Example: Replace the libev allocator with one that waits a bit and then |
398 | retries (example requires a standards-compliant \f(CW\*(C`realloc\*(C'\fR). |
414 | retries. |
399 | .Sp |
415 | .Sp |
400 | .Vb 6 |
416 | .Vb 8 |
401 | \& static void * |
417 | \& static void * |
402 | \& persistent_realloc (void *ptr, size_t size) |
418 | \& persistent_realloc (void *ptr, size_t size) |
403 | \& { |
419 | \& { |
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420 | \& if (!size) |
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421 | \& { |
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422 | \& free (ptr); |
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423 | \& return 0; |
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424 | \& } |
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425 | \& |
404 | \& for (;;) |
426 | \& for (;;) |
405 | \& { |
427 | \& { |
406 | \& void *newptr = realloc (ptr, size); |
428 | \& void *newptr = realloc (ptr, size); |
407 | \& |
429 | \& |
408 | \& if (newptr) |
430 | \& if (newptr) |
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536 | make libev check for a fork in each iteration by enabling this flag. |
558 | make libev check for a fork in each iteration by enabling this flag. |
537 | .Sp |
559 | .Sp |
538 | This works by calling \f(CW\*(C`getpid ()\*(C'\fR on every iteration of the loop, |
560 | This works by calling \f(CW\*(C`getpid ()\*(C'\fR on every iteration of the loop, |
539 | and thus this might slow down your event loop if you do a lot of loop |
561 | and thus this might slow down your event loop if you do a lot of loop |
540 | iterations and little real work, but is usually not noticeable (on my |
562 | iterations and little real work, but is usually not noticeable (on my |
541 | GNU/Linux system for example, \f(CW\*(C`getpid\*(C'\fR is actually a simple 5\-insn sequence |
563 | GNU/Linux system for example, \f(CW\*(C`getpid\*(C'\fR is actually a simple 5\-insn |
542 | without a system call and thus \fIvery\fR fast, but my GNU/Linux system also has |
564 | sequence without a system call and thus \fIvery\fR fast, but my GNU/Linux |
543 | \&\f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). |
565 | system also has \f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). (Update: glibc |
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566 | versions 2.25 apparently removed the \f(CW\*(C`getpid\*(C'\fR optimisation again). |
544 | .Sp |
567 | .Sp |
545 | The big advantage of this flag is that you can forget about fork (and |
568 | The big advantage of this flag is that you can forget about fork (and |
546 | forget about forgetting to tell libev about forking, although you still |
569 | forget about forgetting to tell libev about forking, although you still |
547 | have to ignore \f(CW\*(C`SIGPIPE\*(C'\fR) when you use this flag. |
570 | have to ignore \f(CW\*(C`SIGPIPE\*(C'\fR) when you use this flag. |
548 | .Sp |
571 | .Sp |
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584 | .Sp |
607 | .Sp |
585 | This flag's behaviour will become the default in future versions of libev. |
608 | This flag's behaviour will become the default in future versions of libev. |
586 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
609 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
587 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
610 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
588 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
611 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
589 | This is your standard \fIselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
612 | This is your standard \fBselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
590 | libev tries to roll its own fd_set with no limits on the number of fds, |
613 | libev tries to roll its own fd_set with no limits on the number of fds, |
591 | but if that fails, expect a fairly low limit on the number of fds when |
614 | but if that fails, expect a fairly low limit on the number of fds when |
592 | using this backend. It doesn't scale too well (O(highest_fd)), but its |
615 | using this backend. It doesn't scale too well (O(highest_fd)), but its |
593 | usually the fastest backend for a low number of (low-numbered :) fds. |
616 | usually the fastest backend for a low number of (low-numbered :) fds. |
594 | .Sp |
617 | .Sp |
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603 | \&\f(CW\*(C`writefds\*(C'\fR set (and to work around Microsoft Windows bugs, also onto the |
626 | \&\f(CW\*(C`writefds\*(C'\fR set (and to work around Microsoft Windows bugs, also onto the |
604 | \&\f(CW\*(C`exceptfds\*(C'\fR set on that platform). |
627 | \&\f(CW\*(C`exceptfds\*(C'\fR set on that platform). |
605 | .ie n .IP """EVBACKEND_POLL"" (value 2, poll backend, available everywhere except on windows)" 4 |
628 | .ie n .IP """EVBACKEND_POLL"" (value 2, poll backend, available everywhere except on windows)" 4 |
606 | .el .IP "\f(CWEVBACKEND_POLL\fR (value 2, poll backend, available everywhere except on windows)" 4 |
629 | .el .IP "\f(CWEVBACKEND_POLL\fR (value 2, poll backend, available everywhere except on windows)" 4 |
607 | .IX Item "EVBACKEND_POLL (value 2, poll backend, available everywhere except on windows)" |
630 | .IX Item "EVBACKEND_POLL (value 2, poll backend, available everywhere except on windows)" |
608 | And this is your standard \fIpoll\fR\|(2) backend. It's more complicated |
631 | And this is your standard \fBpoll\fR\|(2) backend. It's more complicated |
609 | than select, but handles sparse fds better and has no artificial |
632 | than select, but handles sparse fds better and has no artificial |
610 | limit on the number of fds you can use (except it will slow down |
633 | limit on the number of fds you can use (except it will slow down |
611 | considerably with a lot of inactive fds). It scales similarly to select, |
634 | considerably with a lot of inactive fds). It scales similarly to select, |
612 | i.e. O(total_fds). See the entry for \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR, above, for |
635 | i.e. O(total_fds). See the entry for \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR, above, for |
613 | performance tips. |
636 | performance tips. |
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615 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR to \f(CW\*(C`POLLIN | POLLERR | POLLHUP\*(C'\fR, and |
638 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR to \f(CW\*(C`POLLIN | POLLERR | POLLHUP\*(C'\fR, and |
616 | \&\f(CW\*(C`EV_WRITE\*(C'\fR to \f(CW\*(C`POLLOUT | POLLERR | POLLHUP\*(C'\fR. |
639 | \&\f(CW\*(C`EV_WRITE\*(C'\fR to \f(CW\*(C`POLLOUT | POLLERR | POLLHUP\*(C'\fR. |
617 | .ie n .IP """EVBACKEND_EPOLL"" (value 4, Linux)" 4 |
640 | .ie n .IP """EVBACKEND_EPOLL"" (value 4, Linux)" 4 |
618 | .el .IP "\f(CWEVBACKEND_EPOLL\fR (value 4, Linux)" 4 |
641 | .el .IP "\f(CWEVBACKEND_EPOLL\fR (value 4, Linux)" 4 |
619 | .IX Item "EVBACKEND_EPOLL (value 4, Linux)" |
642 | .IX Item "EVBACKEND_EPOLL (value 4, Linux)" |
620 | Use the linux-specific \fIepoll\fR\|(7) interface (for both pre\- and post\-2.6.9 |
643 | Use the linux-specific \fBepoll\fR\|(7) interface (for both pre\- and post\-2.6.9 |
621 | kernels). |
644 | kernels). |
622 | .Sp |
645 | .Sp |
623 | For few fds, this backend is a bit little slower than poll and select, but |
646 | For few fds, this backend is a bit little slower than poll and select, but |
624 | it scales phenomenally better. While poll and select usually scale like |
647 | it scales phenomenally better. While poll and select usually scale like |
625 | O(total_fds) where total_fds is the total number of fds (or the highest |
648 | O(total_fds) where total_fds is the total number of fds (or the highest |
… | |
… | |
671 | All this means that, in practice, \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR can be as fast or |
694 | All this means that, in practice, \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR can be as fast or |
672 | faster than epoll for maybe up to a hundred file descriptors, depending on |
695 | faster than epoll for maybe up to a hundred file descriptors, depending on |
673 | the usage. So sad. |
696 | the usage. So sad. |
674 | .Sp |
697 | .Sp |
675 | While nominally embeddable in other event loops, this feature is broken in |
698 | While nominally embeddable in other event loops, this feature is broken in |
676 | all kernel versions tested so far. |
699 | a lot of kernel revisions, but probably(!) works in current versions. |
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700 | .Sp |
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701 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR and \f(CW\*(C`EV_WRITE\*(C'\fR in the same way as |
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702 | \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR. |
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703 | .ie n .IP """EVBACKEND_LINUXAIO"" (value 64, Linux)" 4 |
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704 | .el .IP "\f(CWEVBACKEND_LINUXAIO\fR (value 64, Linux)" 4 |
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705 | .IX Item "EVBACKEND_LINUXAIO (value 64, Linux)" |
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706 | Use the linux-specific linux aio (\fInot\fR \f(CWaio(7)\fR but \f(CWio_submit(2)\fR) event interface available in post\-4.18 kernels. |
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707 | .Sp |
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708 | If this backend works for you (as of this writing, it was very |
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709 | experimental), it is the best event interface available on linux and might |
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710 | be well worth enabling it \- if it isn't available in your kernel this will |
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711 | be detected and this backend will be skipped. |
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712 | .Sp |
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713 | This backend can batch oneshot requests and supports a user-space ring |
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714 | buffer to receive events. It also doesn't suffer from most of the design |
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715 | problems of epoll (such as not being able to remove event sources from |
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716 | the epoll set), and generally sounds too good to be true. Because, this |
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717 | being the linux kernel, of course it suffers from a whole new set of |
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718 | limitations. |
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719 | .Sp |
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720 | For one, it is not easily embeddable (but probably could be done using |
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721 | an event fd at some extra overhead). It also is subject to a system wide |
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722 | limit that can be configured in \fI/proc/sys/fs/aio\-max\-nr\fR \- each loop |
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723 | currently requires \f(CW61\fR of this number. If no aio requests are left, this |
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724 | backend will be skipped during initialisation. |
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725 | .Sp |
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726 | Most problematic in practise, however, is that not all file descriptors |
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727 | work with it. For example, in linux 5.1, tcp sockets, pipes, event fds, |
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728 | files, \fI/dev/null\fR and a few others are supported, but ttys do not work |
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729 | (probably because of a bug), so this is not (yet?) a generic event polling |
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730 | interface. |
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731 | .Sp |
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732 | To work around this latter problem, the current version of libev uses |
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733 | epoll as a fallback for file deescriptor types that do not work. Epoll |
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734 | is used in, kind of, slow mode that hopefully avoids most of its design |
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735 | problems and requires 1\-3 extra syscalls per active fd every iteration. |
677 | .Sp |
736 | .Sp |
678 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR and \f(CW\*(C`EV_WRITE\*(C'\fR in the same way as |
737 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR and \f(CW\*(C`EV_WRITE\*(C'\fR in the same way as |
679 | \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR. |
738 | \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR. |
680 | .ie n .IP """EVBACKEND_KQUEUE"" (value 8, most \s-1BSD\s0 clones)" 4 |
739 | .ie n .IP """EVBACKEND_KQUEUE"" (value 8, most \s-1BSD\s0 clones)" 4 |
681 | .el .IP "\f(CWEVBACKEND_KQUEUE\fR (value 8, most \s-1BSD\s0 clones)" 4 |
740 | .el .IP "\f(CWEVBACKEND_KQUEUE\fR (value 8, most \s-1BSD\s0 clones)" 4 |
… | |
… | |
784 | Example: Use whatever libev has to offer, but make sure that kqueue is |
843 | Example: Use whatever libev has to offer, but make sure that kqueue is |
785 | used if available. |
844 | used if available. |
786 | .Sp |
845 | .Sp |
787 | .Vb 1 |
846 | .Vb 1 |
788 | \& struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_KQUEUE); |
847 | \& struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_KQUEUE); |
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848 | .Ve |
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849 | .Sp |
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850 | Example: Similarly, on linux, you mgiht want to take advantage of the |
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851 | linux aio backend if possible, but fall back to something else if that |
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852 | isn't available. |
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853 | .Sp |
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854 | .Vb 1 |
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855 | \& struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_LINUXAIO); |
789 | .Ve |
856 | .Ve |
790 | .RE |
857 | .RE |
791 | .IP "ev_loop_destroy (loop)" 4 |
858 | .IP "ev_loop_destroy (loop)" 4 |
792 | .IX Item "ev_loop_destroy (loop)" |
859 | .IX Item "ev_loop_destroy (loop)" |
793 | Destroys an event loop object (frees all memory and kernel state |
860 | Destroys an event loop object (frees all memory and kernel state |
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1364 | bug in your program. |
1431 | bug in your program. |
1365 | .Sp |
1432 | .Sp |
1366 | Libev will usually signal a few \*(L"dummy\*(R" events together with an error, for |
1433 | Libev will usually signal a few \*(L"dummy\*(R" events together with an error, for |
1367 | example it might indicate that a fd is readable or writable, and if your |
1434 | example it might indicate that a fd is readable or writable, and if your |
1368 | callbacks is well-written it can just attempt the operation and cope with |
1435 | callbacks is well-written it can just attempt the operation and cope with |
1369 | the error from \fIread()\fR or \fIwrite()\fR. This will not work in multi-threaded |
1436 | the error from \fBread()\fR or \fBwrite()\fR. This will not work in multi-threaded |
1370 | programs, though, as the fd could already be closed and reused for another |
1437 | programs, though, as the fd could already be closed and reused for another |
1371 | thing, so beware. |
1438 | thing, so beware. |
1372 | .SS "\s-1GENERIC WATCHER FUNCTIONS\s0" |
1439 | .SS "\s-1GENERIC WATCHER FUNCTIONS\s0" |
1373 | .IX Subsection "GENERIC WATCHER FUNCTIONS" |
1440 | .IX Subsection "GENERIC WATCHER FUNCTIONS" |
1374 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
1441 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
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1725 | But really, best use non-blocking mode. |
1792 | But really, best use non-blocking mode. |
1726 | .PP |
1793 | .PP |
1727 | \fIThe special problem of disappearing file descriptors\fR |
1794 | \fIThe special problem of disappearing file descriptors\fR |
1728 | .IX Subsection "The special problem of disappearing file descriptors" |
1795 | .IX Subsection "The special problem of disappearing file descriptors" |
1729 | .PP |
1796 | .PP |
1730 | Some backends (e.g. kqueue, epoll) need to be told about closing a file |
1797 | Some backends (e.g. kqueue, epoll, linuxaio) need to be told about closing |
1731 | descriptor (either due to calling \f(CW\*(C`close\*(C'\fR explicitly or any other means, |
1798 | a file descriptor (either due to calling \f(CW\*(C`close\*(C'\fR explicitly or any other |
1732 | such as \f(CW\*(C`dup2\*(C'\fR). The reason is that you register interest in some file |
1799 | means, such as \f(CW\*(C`dup2\*(C'\fR). The reason is that you register interest in some |
1733 | descriptor, but when it goes away, the operating system will silently drop |
1800 | file descriptor, but when it goes away, the operating system will silently |
1734 | this interest. If another file descriptor with the same number then is |
1801 | drop this interest. If another file descriptor with the same number then |
1735 | registered with libev, there is no efficient way to see that this is, in |
1802 | is registered with libev, there is no efficient way to see that this is, |
1736 | fact, a different file descriptor. |
1803 | in fact, a different file descriptor. |
1737 | .PP |
1804 | .PP |
1738 | To avoid having to explicitly tell libev about such cases, libev follows |
1805 | To avoid having to explicitly tell libev about such cases, libev follows |
1739 | the following policy: Each time \f(CW\*(C`ev_io_set\*(C'\fR is being called, libev |
1806 | the following policy: Each time \f(CW\*(C`ev_io_set\*(C'\fR is being called, libev |
1740 | will assume that this is potentially a new file descriptor, otherwise |
1807 | will assume that this is potentially a new file descriptor, otherwise |
1741 | it is assumed that the file descriptor stays the same. That means that |
1808 | it is assumed that the file descriptor stays the same. That means that |
… | |
… | |
1793 | reuse the same code path. |
1860 | reuse the same code path. |
1794 | .PP |
1861 | .PP |
1795 | \fIThe special problem of fork\fR |
1862 | \fIThe special problem of fork\fR |
1796 | .IX Subsection "The special problem of fork" |
1863 | .IX Subsection "The special problem of fork" |
1797 | .PP |
1864 | .PP |
1798 | Some backends (epoll, kqueue) do not support \f(CW\*(C`fork ()\*(C'\fR at all or exhibit |
1865 | Some backends (epoll, kqueue, probably linuxaio) do not support \f(CW\*(C`fork ()\*(C'\fR |
1799 | useless behaviour. Libev fully supports fork, but needs to be told about |
1866 | at all or exhibit useless behaviour. Libev fully supports fork, but needs |
1800 | it in the child if you want to continue to use it in the child. |
1867 | to be told about it in the child if you want to continue to use it in the |
|
|
1868 | child. |
1801 | .PP |
1869 | .PP |
1802 | To support fork in your child processes, you have to call \f(CW\*(C`ev_loop_fork |
1870 | To support fork in your child processes, you have to call \f(CW\*(C`ev_loop_fork |
1803 | ()\*(C'\fR after a fork in the child, enable \f(CW\*(C`EVFLAG_FORKCHECK\*(C'\fR, or resort to |
1871 | ()\*(C'\fR after a fork in the child, enable \f(CW\*(C`EVFLAG_FORKCHECK\*(C'\fR, or resort to |
1804 | \&\f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \f(CW\*(C`EVBACKEND_POLL\*(C'\fR. |
1872 | \&\f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \f(CW\*(C`EVBACKEND_POLL\*(C'\fR. |
1805 | .PP |
1873 | .PP |
… | |
… | |
1810 | when writing to a pipe whose other end has been closed, your program gets |
1878 | when writing to a pipe whose other end has been closed, your program gets |
1811 | sent a \s-1SIGPIPE,\s0 which, by default, aborts your program. For most programs |
1879 | sent a \s-1SIGPIPE,\s0 which, by default, aborts your program. For most programs |
1812 | this is sensible behaviour, for daemons, this is usually undesirable. |
1880 | this is sensible behaviour, for daemons, this is usually undesirable. |
1813 | .PP |
1881 | .PP |
1814 | So when you encounter spurious, unexplained daemon exits, make sure you |
1882 | So when you encounter spurious, unexplained daemon exits, make sure you |
1815 | ignore \s-1SIGPIPE \s0(and maybe make sure you log the exit status of your daemon |
1883 | ignore \s-1SIGPIPE\s0 (and maybe make sure you log the exit status of your daemon |
1816 | somewhere, as that would have given you a big clue). |
1884 | somewhere, as that would have given you a big clue). |
1817 | .PP |
1885 | .PP |
1818 | \fIThe special problem of \fIaccept()\fIing when you can't\fR |
1886 | \fIThe special problem of \f(BIaccept()\fIing when you can't\fR |
1819 | .IX Subsection "The special problem of accept()ing when you can't" |
1887 | .IX Subsection "The special problem of accept()ing when you can't" |
1820 | .PP |
1888 | .PP |
1821 | Many implementations of the \s-1POSIX \s0\f(CW\*(C`accept\*(C'\fR function (for example, |
1889 | Many implementations of the \s-1POSIX\s0 \f(CW\*(C`accept\*(C'\fR function (for example, |
1822 | found in post\-2004 Linux) have the peculiar behaviour of not removing a |
1890 | found in post\-2004 Linux) have the peculiar behaviour of not removing a |
1823 | connection from the pending queue in all error cases. |
1891 | connection from the pending queue in all error cases. |
1824 | .PP |
1892 | .PP |
1825 | For example, larger servers often run out of file descriptors (because |
1893 | For example, larger servers often run out of file descriptors (because |
1826 | of resource limits), causing \f(CW\*(C`accept\*(C'\fR to fail with \f(CW\*(C`ENFILE\*(C'\fR but not |
1894 | of resource limits), causing \f(CW\*(C`accept\*(C'\fR to fail with \f(CW\*(C`ENFILE\*(C'\fR but not |
… | |
… | |
2250 | .IX Item "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)" |
2318 | .IX Item "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)" |
2251 | .PD 0 |
2319 | .PD 0 |
2252 | .IP "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" 4 |
2320 | .IP "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" 4 |
2253 | .IX Item "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" |
2321 | .IX Item "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" |
2254 | .PD |
2322 | .PD |
2255 | Configure the timer to trigger after \f(CW\*(C`after\*(C'\fR seconds. If \f(CW\*(C`repeat\*(C'\fR |
2323 | Configure the timer to trigger after \f(CW\*(C`after\*(C'\fR seconds (fractional and |
2256 | is \f(CW0.\fR, then it will automatically be stopped once the timeout is |
2324 | negative values are supported). If \f(CW\*(C`repeat\*(C'\fR is \f(CW0.\fR, then it will |
2257 | reached. If it is positive, then the timer will automatically be |
2325 | automatically be stopped once the timeout is reached. If it is positive, |
2258 | configured to trigger again \f(CW\*(C`repeat\*(C'\fR seconds later, again, and again, |
2326 | then the timer will automatically be configured to trigger again \f(CW\*(C`repeat\*(C'\fR |
2259 | until stopped manually. |
2327 | seconds later, again, and again, until stopped manually. |
2260 | .Sp |
2328 | .Sp |
2261 | The timer itself will do a best-effort at avoiding drift, that is, if |
2329 | The timer itself will do a best-effort at avoiding drift, that is, if |
2262 | you configure a timer to trigger every 10 seconds, then it will normally |
2330 | you configure a timer to trigger every 10 seconds, then it will normally |
2263 | trigger at exactly 10 second intervals. If, however, your program cannot |
2331 | trigger at exactly 10 second intervals. If, however, your program cannot |
2264 | keep up with the timer (because it takes longer than those 10 seconds to |
2332 | keep up with the timer (because it takes longer than those 10 seconds to |
… | |
… | |
2361 | \&\f(CW\*(C`ev_timer\*(C'\fR, which would still trigger roughly 10 seconds after starting |
2429 | \&\f(CW\*(C`ev_timer\*(C'\fR, which would still trigger roughly 10 seconds after starting |
2362 | it, as it uses a relative timeout). |
2430 | it, as it uses a relative timeout). |
2363 | .PP |
2431 | .PP |
2364 | \&\f(CW\*(C`ev_periodic\*(C'\fR watchers can also be used to implement vastly more complex |
2432 | \&\f(CW\*(C`ev_periodic\*(C'\fR watchers can also be used to implement vastly more complex |
2365 | timers, such as triggering an event on each \*(L"midnight, local time\*(R", or |
2433 | timers, such as triggering an event on each \*(L"midnight, local time\*(R", or |
2366 | other complicated rules. This cannot be done with \f(CW\*(C`ev_timer\*(C'\fR watchers, as |
2434 | other complicated rules. This cannot easily be done with \f(CW\*(C`ev_timer\*(C'\fR |
2367 | those cannot react to time jumps. |
2435 | watchers, as those cannot react to time jumps. |
2368 | .PP |
2436 | .PP |
2369 | As with timers, the callback is guaranteed to be invoked only when the |
2437 | As with timers, the callback is guaranteed to be invoked only when the |
2370 | point in time where it is supposed to trigger has passed. If multiple |
2438 | point in time where it is supposed to trigger has passed. If multiple |
2371 | timers become ready during the same loop iteration then the ones with |
2439 | timers become ready during the same loop iteration then the ones with |
2372 | earlier time-out values are invoked before ones with later time-out values |
2440 | earlier time-out values are invoked before ones with later time-out values |
… | |
… | |
2433 | In this mode the values for \f(CW\*(C`interval\*(C'\fR and \f(CW\*(C`offset\*(C'\fR are both being |
2501 | In this mode the values for \f(CW\*(C`interval\*(C'\fR and \f(CW\*(C`offset\*(C'\fR are both being |
2434 | ignored. Instead, each time the periodic watcher gets scheduled, the |
2502 | ignored. Instead, each time the periodic watcher gets scheduled, the |
2435 | reschedule callback will be called with the watcher as first, and the |
2503 | reschedule callback will be called with the watcher as first, and the |
2436 | current time as second argument. |
2504 | current time as second argument. |
2437 | .Sp |
2505 | .Sp |
2438 | \&\s-1NOTE: \s0\fIThis callback \s-1MUST NOT\s0 stop or destroy any periodic watcher, ever, |
2506 | \&\s-1NOTE:\s0 \fIThis callback \s-1MUST NOT\s0 stop or destroy any periodic watcher, ever, |
2439 | or make \s-1ANY\s0 other event loop modifications whatsoever, unless explicitly |
2507 | or make \s-1ANY\s0 other event loop modifications whatsoever, unless explicitly |
2440 | allowed by documentation here\fR. |
2508 | allowed by documentation here\fR. |
2441 | .Sp |
2509 | .Sp |
2442 | If you need to stop it, return \f(CW\*(C`now + 1e30\*(C'\fR (or so, fudge fudge) and stop |
2510 | If you need to stop it, return \f(CW\*(C`now + 1e30\*(C'\fR (or so, fudge fudge) and stop |
2443 | it afterwards (e.g. by starting an \f(CW\*(C`ev_prepare\*(C'\fR watcher, which is the |
2511 | it afterwards (e.g. by starting an \f(CW\*(C`ev_prepare\*(C'\fR watcher, which is the |
… | |
… | |
2457 | It must return the next time to trigger, based on the passed time value |
2525 | It must return the next time to trigger, based on the passed time value |
2458 | (that is, the lowest time value larger than to the second argument). It |
2526 | (that is, the lowest time value larger than to the second argument). It |
2459 | will usually be called just before the callback will be triggered, but |
2527 | will usually be called just before the callback will be triggered, but |
2460 | might be called at other times, too. |
2528 | might be called at other times, too. |
2461 | .Sp |
2529 | .Sp |
2462 | \&\s-1NOTE: \s0\fIThis callback must always return a time that is higher than or |
2530 | \&\s-1NOTE:\s0 \fIThis callback must always return a time that is higher than or |
2463 | equal to the passed \f(CI\*(C`now\*(C'\fI value\fR. |
2531 | equal to the passed \f(CI\*(C`now\*(C'\fI value\fR. |
2464 | .Sp |
2532 | .Sp |
2465 | This can be used to create very complex timers, such as a timer that |
2533 | This can be used to create very complex timers, such as a timer that |
2466 | triggers on \*(L"next midnight, local time\*(R". To do this, you would calculate the |
2534 | triggers on \*(L"next midnight, local time\*(R". To do this, you would calculate |
2467 | next midnight after \f(CW\*(C`now\*(C'\fR and return the timestamp value for this. How |
2535 | the next midnight after \f(CW\*(C`now\*(C'\fR and return the timestamp value for |
2468 | you do this is, again, up to you (but it is not trivial, which is the main |
2536 | this. Here is a (completely untested, no error checking) example on how to |
2469 | reason I omitted it as an example). |
2537 | do this: |
|
|
2538 | .Sp |
|
|
2539 | .Vb 1 |
|
|
2540 | \& #include <time.h> |
|
|
2541 | \& |
|
|
2542 | \& static ev_tstamp |
|
|
2543 | \& my_rescheduler (ev_periodic *w, ev_tstamp now) |
|
|
2544 | \& { |
|
|
2545 | \& time_t tnow = (time_t)now; |
|
|
2546 | \& struct tm tm; |
|
|
2547 | \& localtime_r (&tnow, &tm); |
|
|
2548 | \& |
|
|
2549 | \& tm.tm_sec = tm.tm_min = tm.tm_hour = 0; // midnight current day |
|
|
2550 | \& ++tm.tm_mday; // midnight next day |
|
|
2551 | \& |
|
|
2552 | \& return mktime (&tm); |
|
|
2553 | \& } |
|
|
2554 | .Ve |
|
|
2555 | .Sp |
|
|
2556 | Note: this code might run into trouble on days that have more then two |
|
|
2557 | midnights (beginning and end). |
2470 | .RE |
2558 | .RE |
2471 | .RS 4 |
2559 | .RS 4 |
2472 | .RE |
2560 | .RE |
2473 | .IP "ev_periodic_again (loop, ev_periodic *)" 4 |
2561 | .IP "ev_periodic_again (loop, ev_periodic *)" 4 |
2474 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
2562 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
… | |
… | |
2592 | The simplest way to ensure that the signal mask is reset in the child is |
2680 | The simplest way to ensure that the signal mask is reset in the child is |
2593 | to install a fork handler with \f(CW\*(C`pthread_atfork\*(C'\fR that resets it. That will |
2681 | to install a fork handler with \f(CW\*(C`pthread_atfork\*(C'\fR that resets it. That will |
2594 | catch fork calls done by libraries (such as the libc) as well. |
2682 | catch fork calls done by libraries (such as the libc) as well. |
2595 | .PP |
2683 | .PP |
2596 | In current versions of libev, the signal will not be blocked indefinitely |
2684 | In current versions of libev, the signal will not be blocked indefinitely |
2597 | unless you use the \f(CW\*(C`signalfd\*(C'\fR \s-1API \s0(\f(CW\*(C`EV_SIGNALFD\*(C'\fR). While this reduces |
2685 | unless you use the \f(CW\*(C`signalfd\*(C'\fR \s-1API\s0 (\f(CW\*(C`EV_SIGNALFD\*(C'\fR). While this reduces |
2598 | the window of opportunity for problems, it will not go away, as libev |
2686 | the window of opportunity for problems, it will not go away, as libev |
2599 | \&\fIhas\fR to modify the signal mask, at least temporarily. |
2687 | \&\fIhas\fR to modify the signal mask, at least temporarily. |
2600 | .PP |
2688 | .PP |
2601 | So I can't stress this enough: \fIIf you do not reset your signal mask when |
2689 | So I can't stress this enough: \fIIf you do not reset your signal mask when |
2602 | you expect it to be empty, you have a race condition in your code\fR. This |
2690 | you expect it to be empty, you have a race condition in your code\fR. This |
… | |
… | |
3644 | is a time window between the event loop checking and resetting the async |
3732 | is a time window between the event loop checking and resetting the async |
3645 | notification, and the callback being invoked. |
3733 | notification, and the callback being invoked. |
3646 | .SH "OTHER FUNCTIONS" |
3734 | .SH "OTHER FUNCTIONS" |
3647 | .IX Header "OTHER FUNCTIONS" |
3735 | .IX Header "OTHER FUNCTIONS" |
3648 | There are some other functions of possible interest. Described. Here. Now. |
3736 | There are some other functions of possible interest. Described. Here. Now. |
3649 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4 |
3737 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback, arg)" 4 |
3650 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" |
3738 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback, arg)" |
3651 | This function combines a simple timer and an I/O watcher, calls your |
3739 | This function combines a simple timer and an I/O watcher, calls your |
3652 | callback on whichever event happens first and automatically stops both |
3740 | callback on whichever event happens first and automatically stops both |
3653 | watchers. This is useful if you want to wait for a single event on an fd |
3741 | watchers. This is useful if you want to wait for a single event on an fd |
3654 | or timeout without having to allocate/configure/start/stop/free one or |
3742 | or timeout without having to allocate/configure/start/stop/free one or |
3655 | more watchers yourself. |
3743 | more watchers yourself. |
… | |
… | |
4105 | The normal C \s-1API\s0 should work fine when used from \*(C+: both ev.h and the |
4193 | The normal C \s-1API\s0 should work fine when used from \*(C+: both ev.h and the |
4106 | libev sources can be compiled as \*(C+. Therefore, code that uses the C \s-1API\s0 |
4194 | libev sources can be compiled as \*(C+. Therefore, code that uses the C \s-1API\s0 |
4107 | will work fine. |
4195 | will work fine. |
4108 | .PP |
4196 | .PP |
4109 | Proper exception specifications might have to be added to callbacks passed |
4197 | Proper exception specifications might have to be added to callbacks passed |
4110 | to libev: exceptions may be thrown only from watcher callbacks, all |
4198 | to libev: exceptions may be thrown only from watcher callbacks, all other |
4111 | other callbacks (allocator, syserr, loop acquire/release and periodic |
4199 | callbacks (allocator, syserr, loop acquire/release and periodic reschedule |
4112 | reschedule callbacks) must not throw exceptions, and might need a \f(CW\*(C`throw |
4200 | callbacks) must not throw exceptions, and might need a \f(CW\*(C`noexcept\*(C'\fR |
4113 | ()\*(C'\fR specification. If you have code that needs to be compiled as both C |
4201 | specification. If you have code that needs to be compiled as both C and |
4114 | and \*(C+ you can use the \f(CW\*(C`EV_THROW\*(C'\fR macro for this: |
4202 | \&\*(C+ you can use the \f(CW\*(C`EV_NOEXCEPT\*(C'\fR macro for this: |
4115 | .PP |
4203 | .PP |
4116 | .Vb 6 |
4204 | .Vb 6 |
4117 | \& static void |
4205 | \& static void |
4118 | \& fatal_error (const char *msg) EV_THROW |
4206 | \& fatal_error (const char *msg) EV_NOEXCEPT |
4119 | \& { |
4207 | \& { |
4120 | \& perror (msg); |
4208 | \& perror (msg); |
4121 | \& abort (); |
4209 | \& abort (); |
4122 | \& } |
4210 | \& } |
4123 | \& |
4211 | \& |
… | |
… | |
4497 | \& #include "ev.c" |
4585 | \& #include "ev.c" |
4498 | .Ve |
4586 | .Ve |
4499 | .PP |
4587 | .PP |
4500 | This will automatically include \fIev.h\fR, too, and should be done in a |
4588 | This will automatically include \fIev.h\fR, too, and should be done in a |
4501 | single C source file only to provide the function implementations. To use |
4589 | single C source file only to provide the function implementations. To use |
4502 | it, do the same for \fIev.h\fR in all files wishing to use this \s-1API \s0(best |
4590 | it, do the same for \fIev.h\fR in all files wishing to use this \s-1API\s0 (best |
4503 | done by writing a wrapper around \fIev.h\fR that you can include instead and |
4591 | done by writing a wrapper around \fIev.h\fR that you can include instead and |
4504 | where you can put other configuration options): |
4592 | where you can put other configuration options): |
4505 | .PP |
4593 | .PP |
4506 | .Vb 2 |
4594 | .Vb 2 |
4507 | \& #define EV_STANDALONE 1 |
4595 | \& #define EV_STANDALONE 1 |
… | |
… | |
4524 | \& ev_win32.c required on win32 platforms only |
4612 | \& ev_win32.c required on win32 platforms only |
4525 | \& |
4613 | \& |
4526 | \& ev_select.c only when select backend is enabled |
4614 | \& ev_select.c only when select backend is enabled |
4527 | \& ev_poll.c only when poll backend is enabled |
4615 | \& ev_poll.c only when poll backend is enabled |
4528 | \& ev_epoll.c only when the epoll backend is enabled |
4616 | \& ev_epoll.c only when the epoll backend is enabled |
|
|
4617 | \& ev_linuxaio.c only when the linux aio backend is enabled |
4529 | \& ev_kqueue.c only when the kqueue backend is enabled |
4618 | \& ev_kqueue.c only when the kqueue backend is enabled |
4530 | \& ev_port.c only when the solaris port backend is enabled |
4619 | \& ev_port.c only when the solaris port backend is enabled |
4531 | .Ve |
4620 | .Ve |
4532 | .PP |
4621 | .PP |
4533 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
4622 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
… | |
… | |
4580 | values when compiling libev vs. including \fIev.h\fR, so it is permissible |
4669 | values when compiling libev vs. including \fIev.h\fR, so it is permissible |
4581 | to redefine them before including \fIev.h\fR without breaking compatibility |
4670 | to redefine them before including \fIev.h\fR without breaking compatibility |
4582 | to a compiled library. All other symbols change the \s-1ABI,\s0 which means all |
4671 | to a compiled library. All other symbols change the \s-1ABI,\s0 which means all |
4583 | users of libev and the libev code itself must be compiled with compatible |
4672 | users of libev and the libev code itself must be compiled with compatible |
4584 | settings. |
4673 | settings. |
4585 | .IP "\s-1EV_COMPAT3 \s0(h)" 4 |
4674 | .IP "\s-1EV_COMPAT3\s0 (h)" 4 |
4586 | .IX Item "EV_COMPAT3 (h)" |
4675 | .IX Item "EV_COMPAT3 (h)" |
4587 | Backwards compatibility is a major concern for libev. This is why this |
4676 | Backwards compatibility is a major concern for libev. This is why this |
4588 | release of libev comes with wrappers for the functions and symbols that |
4677 | release of libev comes with wrappers for the functions and symbols that |
4589 | have been renamed between libev version 3 and 4. |
4678 | have been renamed between libev version 3 and 4. |
4590 | .Sp |
4679 | .Sp |
… | |
… | |
4595 | typedef in that case. |
4684 | typedef in that case. |
4596 | .Sp |
4685 | .Sp |
4597 | In some future version, the default for \f(CW\*(C`EV_COMPAT3\*(C'\fR will become \f(CW0\fR, |
4686 | In some future version, the default for \f(CW\*(C`EV_COMPAT3\*(C'\fR will become \f(CW0\fR, |
4598 | and in some even more future version the compatibility code will be |
4687 | and in some even more future version the compatibility code will be |
4599 | removed completely. |
4688 | removed completely. |
4600 | .IP "\s-1EV_STANDALONE \s0(h)" 4 |
4689 | .IP "\s-1EV_STANDALONE\s0 (h)" 4 |
4601 | .IX Item "EV_STANDALONE (h)" |
4690 | .IX Item "EV_STANDALONE (h)" |
4602 | Must always be \f(CW1\fR if you do not use autoconf configuration, which |
4691 | Must always be \f(CW1\fR if you do not use autoconf configuration, which |
4603 | keeps libev from including \fIconfig.h\fR, and it also defines dummy |
4692 | keeps libev from including \fIconfig.h\fR, and it also defines dummy |
4604 | implementations for some libevent functions (such as logging, which is not |
4693 | implementations for some libevent functions (such as logging, which is not |
4605 | supported). It will also not define any of the structs usually found in |
4694 | supported). It will also not define any of the structs usually found in |
… | |
… | |
4714 | If defined to be \f(CW1\fR, libev will compile in support for the Linux |
4803 | If defined to be \f(CW1\fR, libev will compile in support for the Linux |
4715 | \&\f(CW\*(C`epoll\*(C'\fR(7) backend. Its availability will be detected at runtime, |
4804 | \&\f(CW\*(C`epoll\*(C'\fR(7) backend. Its availability will be detected at runtime, |
4716 | otherwise another method will be used as fallback. This is the preferred |
4805 | otherwise another method will be used as fallback. This is the preferred |
4717 | backend for GNU/Linux systems. If undefined, it will be enabled if the |
4806 | backend for GNU/Linux systems. If undefined, it will be enabled if the |
4718 | headers indicate GNU/Linux + Glibc 2.4 or newer, otherwise disabled. |
4807 | headers indicate GNU/Linux + Glibc 2.4 or newer, otherwise disabled. |
|
|
4808 | .IP "\s-1EV_USE_LINUXAIO\s0" 4 |
|
|
4809 | .IX Item "EV_USE_LINUXAIO" |
|
|
4810 | If defined to be \f(CW1\fR, libev will compile in support for the Linux |
|
|
4811 | aio backend. Due to it's currenbt limitations it has to be requested |
|
|
4812 | explicitly. If undefined, it will be enabled on linux, otherwise |
|
|
4813 | disabled. |
4719 | .IP "\s-1EV_USE_KQUEUE\s0" 4 |
4814 | .IP "\s-1EV_USE_KQUEUE\s0" 4 |
4720 | .IX Item "EV_USE_KQUEUE" |
4815 | .IX Item "EV_USE_KQUEUE" |
4721 | If defined to be \f(CW1\fR, libev will compile in support for the \s-1BSD\s0 style |
4816 | If defined to be \f(CW1\fR, libev will compile in support for the \s-1BSD\s0 style |
4722 | \&\f(CW\*(C`kqueue\*(C'\fR(2) backend. Its actual availability will be detected at runtime, |
4817 | \&\f(CW\*(C`kqueue\*(C'\fR(2) backend. Its actual availability will be detected at runtime, |
4723 | otherwise another method will be used as fallback. This is the preferred |
4818 | otherwise another method will be used as fallback. This is the preferred |
… | |
… | |
4763 | handler \*(L"locking\*(R" as well as for signal and thread safety in \f(CW\*(C`ev_async\*(C'\fR |
4858 | handler \*(L"locking\*(R" as well as for signal and thread safety in \f(CW\*(C`ev_async\*(C'\fR |
4764 | watchers. |
4859 | watchers. |
4765 | .Sp |
4860 | .Sp |
4766 | In the absence of this define, libev will use \f(CW\*(C`sig_atomic_t volatile\*(C'\fR |
4861 | In the absence of this define, libev will use \f(CW\*(C`sig_atomic_t volatile\*(C'\fR |
4767 | (from \fIsignal.h\fR), which is usually good enough on most platforms. |
4862 | (from \fIsignal.h\fR), which is usually good enough on most platforms. |
4768 | .IP "\s-1EV_H \s0(h)" 4 |
4863 | .IP "\s-1EV_H\s0 (h)" 4 |
4769 | .IX Item "EV_H (h)" |
4864 | .IX Item "EV_H (h)" |
4770 | The name of the \fIev.h\fR header file used to include it. The default if |
4865 | The name of the \fIev.h\fR header file used to include it. The default if |
4771 | undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be |
4866 | undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be |
4772 | used to virtually rename the \fIev.h\fR header file in case of conflicts. |
4867 | used to virtually rename the \fIev.h\fR header file in case of conflicts. |
4773 | .IP "\s-1EV_CONFIG_H \s0(h)" 4 |
4868 | .IP "\s-1EV_CONFIG_H\s0 (h)" 4 |
4774 | .IX Item "EV_CONFIG_H (h)" |
4869 | .IX Item "EV_CONFIG_H (h)" |
4775 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
4870 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
4776 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
4871 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
4777 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
4872 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
4778 | .IP "\s-1EV_EVENT_H \s0(h)" 4 |
4873 | .IP "\s-1EV_EVENT_H\s0 (h)" 4 |
4779 | .IX Item "EV_EVENT_H (h)" |
4874 | .IX Item "EV_EVENT_H (h)" |
4780 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
4875 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
4781 | of how the \fIevent.h\fR header can be found, the default is \f(CW"event.h"\fR. |
4876 | of how the \fIevent.h\fR header can be found, the default is \f(CW"event.h"\fR. |
4782 | .IP "\s-1EV_PROTOTYPES \s0(h)" 4 |
4877 | .IP "\s-1EV_PROTOTYPES\s0 (h)" 4 |
4783 | .IX Item "EV_PROTOTYPES (h)" |
4878 | .IX Item "EV_PROTOTYPES (h)" |
4784 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
4879 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
4785 | prototypes, but still define all the structs and other symbols. This is |
4880 | prototypes, but still define all the structs and other symbols. This is |
4786 | occasionally useful if you want to provide your own wrapper functions |
4881 | occasionally useful if you want to provide your own wrapper functions |
4787 | around libev functions. |
4882 | around libev functions. |
… | |
… | |
4996 | .Vb 3 |
5091 | .Vb 3 |
4997 | \& #define EV_COMMON \e |
5092 | \& #define EV_COMMON \e |
4998 | \& SV *self; /* contains this struct */ \e |
5093 | \& SV *self; /* contains this struct */ \e |
4999 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
5094 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
5000 | .Ve |
5095 | .Ve |
5001 | .IP "\s-1EV_CB_DECLARE \s0(type)" 4 |
5096 | .IP "\s-1EV_CB_DECLARE\s0 (type)" 4 |
5002 | .IX Item "EV_CB_DECLARE (type)" |
5097 | .IX Item "EV_CB_DECLARE (type)" |
5003 | .PD 0 |
5098 | .PD 0 |
5004 | .IP "\s-1EV_CB_INVOKE \s0(watcher, revents)" 4 |
5099 | .IP "\s-1EV_CB_INVOKE\s0 (watcher, revents)" 4 |
5005 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
5100 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
5006 | .IP "ev_set_cb (ev, cb)" 4 |
5101 | .IP "ev_set_cb (ev, cb)" 4 |
5007 | .IX Item "ev_set_cb (ev, cb)" |
5102 | .IX Item "ev_set_cb (ev, cb)" |
5008 | .PD |
5103 | .PD |
5009 | Can be used to change the callback member declaration in each watcher, |
5104 | Can be used to change the callback member declaration in each watcher, |
… | |
… | |
5012 | their default definitions. One possible use for overriding these is to |
5107 | their default definitions. One possible use for overriding these is to |
5013 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
5108 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
5014 | method calls instead of plain function calls in \*(C+. |
5109 | method calls instead of plain function calls in \*(C+. |
5015 | .SS "\s-1EXPORTED API SYMBOLS\s0" |
5110 | .SS "\s-1EXPORTED API SYMBOLS\s0" |
5016 | .IX Subsection "EXPORTED API SYMBOLS" |
5111 | .IX Subsection "EXPORTED API SYMBOLS" |
5017 | If you need to re-export the \s-1API \s0(e.g. via a \s-1DLL\s0) and you need a list of |
5112 | If you need to re-export the \s-1API\s0 (e.g. via a \s-1DLL\s0) and you need a list of |
5018 | exported symbols, you can use the provided \fISymbol.*\fR files which list |
5113 | exported symbols, you can use the provided \fISymbol.*\fR files which list |
5019 | all public symbols, one per line: |
5114 | all public symbols, one per line: |
5020 | .PP |
5115 | .PP |
5021 | .Vb 2 |
5116 | .Vb 2 |
5022 | \& Symbols.ev for libev proper |
5117 | \& Symbols.ev for libev proper |
… | |
… | |
5254 | .PP |
5349 | .PP |
5255 | \fI\f(CI\*(C`select\*(C'\fI is buggy\fR |
5350 | \fI\f(CI\*(C`select\*(C'\fI is buggy\fR |
5256 | .IX Subsection "select is buggy" |
5351 | .IX Subsection "select is buggy" |
5257 | .PP |
5352 | .PP |
5258 | All that's left is \f(CW\*(C`select\*(C'\fR, and of course Apple found a way to fuck this |
5353 | All that's left is \f(CW\*(C`select\*(C'\fR, and of course Apple found a way to fuck this |
5259 | one up as well: On \s-1OS/X, \s0\f(CW\*(C`select\*(C'\fR actively limits the number of file |
5354 | one up as well: On \s-1OS/X,\s0 \f(CW\*(C`select\*(C'\fR actively limits the number of file |
5260 | descriptors you can pass in to 1024 \- your program suddenly crashes when |
5355 | descriptors you can pass in to 1024 \- your program suddenly crashes when |
5261 | you use more. |
5356 | you use more. |
5262 | .PP |
5357 | .PP |
5263 | There is an undocumented \*(L"workaround\*(R" for this \- defining |
5358 | There is an undocumented \*(L"workaround\*(R" for this \- defining |
5264 | \&\f(CW\*(C`_DARWIN_UNLIMITED_SELECT\*(C'\fR, which libev tries to use, so select \fIshould\fR |
5359 | \&\f(CW\*(C`_DARWIN_UNLIMITED_SELECT\*(C'\fR, which libev tries to use, so select \fIshould\fR |