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126 | .IX Title "LIBEV 3" |
135 | .IX Title "LIBEV 3" |
127 | .TH LIBEV 3 "2012-11-13" "libev-4.11" "libev - high performance full featured event loop" |
136 | .TH LIBEV 3 "2017-06-21" "libev-4.24" "libev - high performance full featured event loop" |
128 | .\" For nroff, turn off justification. Always turn off hyphenation; it makes |
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130 | .if n .ad l |
139 | .if n .ad l |
131 | .nh |
140 | .nh |
132 | .SH "NAME" |
141 | .SH "NAME" |
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134 | .SH "SYNOPSIS" |
143 | .SH "SYNOPSIS" |
135 | .IX Header "SYNOPSIS" |
144 | .IX Header "SYNOPSIS" |
136 | .Vb 1 |
145 | .Vb 1 |
137 | \& #include <ev.h> |
146 | \& #include <ev.h> |
138 | .Ve |
147 | .Ve |
139 | .SS "\s-1EXAMPLE\s0 \s-1PROGRAM\s0" |
148 | .SS "\s-1EXAMPLE PROGRAM\s0" |
140 | .IX Subsection "EXAMPLE PROGRAM" |
149 | .IX Subsection "EXAMPLE PROGRAM" |
141 | .Vb 2 |
150 | .Vb 2 |
142 | \& // a single header file is required |
151 | \& // a single header file is required |
143 | \& #include <ev.h> |
152 | \& #include <ev.h> |
144 | \& |
153 | \& |
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212 | throughout this document. |
221 | throughout this document. |
213 | .SH "WHAT TO READ WHEN IN A HURRY" |
222 | .SH "WHAT TO READ WHEN IN A HURRY" |
214 | .IX Header "WHAT TO READ WHEN IN A HURRY" |
223 | .IX Header "WHAT TO READ WHEN IN A HURRY" |
215 | This manual tries to be very detailed, but unfortunately, this also makes |
224 | This manual tries to be very detailed, but unfortunately, this also makes |
216 | it very long. If you just want to know the basics of libev, I suggest |
225 | it very long. If you just want to know the basics of libev, I suggest |
217 | reading \*(L"\s-1ANATOMY\s0 \s-1OF\s0 A \s-1WATCHER\s0\*(R", then the \*(L"\s-1EXAMPLE\s0 \s-1PROGRAM\s0\*(R" above and |
226 | reading \*(L"\s-1ANATOMY OF A WATCHER\*(R"\s0, then the \*(L"\s-1EXAMPLE PROGRAM\*(R"\s0 above and |
218 | look up the missing functions in \*(L"\s-1GLOBAL\s0 \s-1FUNCTIONS\s0\*(R" and the \f(CW\*(C`ev_io\*(C'\fR and |
227 | look up the missing functions in \*(L"\s-1GLOBAL FUNCTIONS\*(R"\s0 and the \f(CW\*(C`ev_io\*(C'\fR and |
219 | \&\f(CW\*(C`ev_timer\*(C'\fR sections in \*(L"\s-1WATCHER\s0 \s-1TYPES\s0\*(R". |
228 | \&\f(CW\*(C`ev_timer\*(C'\fR sections in \*(L"\s-1WATCHER TYPES\*(R"\s0. |
220 | .SH "ABOUT LIBEV" |
229 | .SH "ABOUT LIBEV" |
221 | .IX Header "ABOUT LIBEV" |
230 | .IX Header "ABOUT LIBEV" |
222 | Libev is an event loop: you register interest in certain events (such as a |
231 | Libev is an event loop: you register interest in certain events (such as a |
223 | file descriptor being readable or a timeout occurring), and it will manage |
232 | file descriptor being readable or a timeout occurring), and it will manage |
224 | these event sources and provide your program with events. |
233 | these event sources and provide your program with events. |
… | |
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255 | more info about various configuration options please have a look at |
264 | more info about various configuration options please have a look at |
256 | \&\fB\s-1EMBED\s0\fR section in this manual. If libev was configured without support |
265 | \&\fB\s-1EMBED\s0\fR section in this manual. If libev was configured without support |
257 | for multiple event loops, then all functions taking an initial argument of |
266 | for multiple event loops, then all functions taking an initial argument of |
258 | name \f(CW\*(C`loop\*(C'\fR (which is always of type \f(CW\*(C`struct ev_loop *\*(C'\fR) will not have |
267 | name \f(CW\*(C`loop\*(C'\fR (which is always of type \f(CW\*(C`struct ev_loop *\*(C'\fR) will not have |
259 | this argument. |
268 | this argument. |
260 | .SS "\s-1TIME\s0 \s-1REPRESENTATION\s0" |
269 | .SS "\s-1TIME REPRESENTATION\s0" |
261 | .IX Subsection "TIME REPRESENTATION" |
270 | .IX Subsection "TIME REPRESENTATION" |
262 | Libev represents time as a single floating point number, representing |
271 | Libev represents time as a single floating point number, representing |
263 | the (fractional) number of seconds since the (\s-1POSIX\s0) epoch (in practice |
272 | the (fractional) number of seconds since the (\s-1POSIX\s0) epoch (in practice |
264 | somewhere near the beginning of 1970, details are complicated, don't |
273 | somewhere near the beginning of 1970, details are complicated, don't |
265 | ask). This type is called \f(CW\*(C`ev_tstamp\*(C'\fR, which is what you should use |
274 | ask). This type is called \f(CW\*(C`ev_tstamp\*(C'\fR, which is what you should use |
… | |
… | |
514 | .IX Item "EVFLAG_NOENV" |
523 | .IX Item "EVFLAG_NOENV" |
515 | If this flag bit is or'ed into the flag value (or the program runs setuid |
524 | If this flag bit is or'ed into the flag value (or the program runs setuid |
516 | or setgid) then libev will \fInot\fR look at the environment variable |
525 | or setgid) then libev will \fInot\fR look at the environment variable |
517 | \&\f(CW\*(C`LIBEV_FLAGS\*(C'\fR. Otherwise (the default), this environment variable will |
526 | \&\f(CW\*(C`LIBEV_FLAGS\*(C'\fR. Otherwise (the default), this environment variable will |
518 | override the flags completely if it is found in the environment. This is |
527 | override the flags completely if it is found in the environment. This is |
519 | useful to try out specific backends to test their performance, or to work |
528 | useful to try out specific backends to test their performance, to work |
520 | around bugs. |
529 | around bugs, or to make libev threadsafe (accessing environment variables |
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530 | cannot be done in a threadsafe way, but usually it works if no other |
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|
531 | thread modifies them). |
521 | .ie n .IP """EVFLAG_FORKCHECK""" 4 |
532 | .ie n .IP """EVFLAG_FORKCHECK""" 4 |
522 | .el .IP "\f(CWEVFLAG_FORKCHECK\fR" 4 |
533 | .el .IP "\f(CWEVFLAG_FORKCHECK\fR" 4 |
523 | .IX Item "EVFLAG_FORKCHECK" |
534 | .IX Item "EVFLAG_FORKCHECK" |
524 | Instead of calling \f(CW\*(C`ev_loop_fork\*(C'\fR manually after a fork, you can also |
535 | Instead of calling \f(CW\*(C`ev_loop_fork\*(C'\fR manually after a fork, you can also |
525 | make libev check for a fork in each iteration by enabling this flag. |
536 | make libev check for a fork in each iteration by enabling this flag. |
… | |
… | |
530 | GNU/Linux system for example, \f(CW\*(C`getpid\*(C'\fR is actually a simple 5\-insn sequence |
541 | GNU/Linux system for example, \f(CW\*(C`getpid\*(C'\fR is actually a simple 5\-insn sequence |
531 | without a system call and thus \fIvery\fR fast, but my GNU/Linux system also has |
542 | without a system call and thus \fIvery\fR fast, but my GNU/Linux system also has |
532 | \&\f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). |
543 | \&\f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). |
533 | .Sp |
544 | .Sp |
534 | The big advantage of this flag is that you can forget about fork (and |
545 | The big advantage of this flag is that you can forget about fork (and |
535 | forget about forgetting to tell libev about forking) when you use this |
546 | forget about forgetting to tell libev about forking, although you still |
536 | flag. |
547 | have to ignore \f(CW\*(C`SIGPIPE\*(C'\fR) when you use this flag. |
537 | .Sp |
548 | .Sp |
538 | This flag setting cannot be overridden or specified in the \f(CW\*(C`LIBEV_FLAGS\*(C'\fR |
549 | This flag setting cannot be overridden or specified in the \f(CW\*(C`LIBEV_FLAGS\*(C'\fR |
539 | environment variable. |
550 | environment variable. |
540 | .ie n .IP """EVFLAG_NOINOTIFY""" 4 |
551 | .ie n .IP """EVFLAG_NOINOTIFY""" 4 |
541 | .el .IP "\f(CWEVFLAG_NOINOTIFY\fR" 4 |
552 | .el .IP "\f(CWEVFLAG_NOINOTIFY\fR" 4 |
… | |
… | |
572 | \&\f(CW\*(C`sigprocmask\*(C'\fR, whose behaviour is officially unspecified. |
583 | \&\f(CW\*(C`sigprocmask\*(C'\fR, whose behaviour is officially unspecified. |
573 | .Sp |
584 | .Sp |
574 | This flag's behaviour will become the default in future versions of libev. |
585 | This flag's behaviour will become the default in future versions of libev. |
575 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
586 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
576 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
587 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
577 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
588 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
578 | This is your standard \fIselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
589 | This is your standard \fIselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
579 | libev tries to roll its own fd_set with no limits on the number of fds, |
590 | libev tries to roll its own fd_set with no limits on the number of fds, |
580 | but if that fails, expect a fairly low limit on the number of fds when |
591 | but if that fails, expect a fairly low limit on the number of fds when |
581 | using this backend. It doesn't scale too well (O(highest_fd)), but its |
592 | using this backend. It doesn't scale too well (O(highest_fd)), but its |
582 | usually the fastest backend for a low number of (low-numbered :) fds. |
593 | usually the fastest backend for a low number of (low-numbered :) fds. |
… | |
… | |
591 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR to the \f(CW\*(C`readfds\*(C'\fR set and \f(CW\*(C`EV_WRITE\*(C'\fR to the |
602 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR to the \f(CW\*(C`readfds\*(C'\fR set and \f(CW\*(C`EV_WRITE\*(C'\fR to the |
592 | \&\f(CW\*(C`writefds\*(C'\fR set (and to work around Microsoft Windows bugs, also onto the |
603 | \&\f(CW\*(C`writefds\*(C'\fR set (and to work around Microsoft Windows bugs, also onto the |
593 | \&\f(CW\*(C`exceptfds\*(C'\fR set on that platform). |
604 | \&\f(CW\*(C`exceptfds\*(C'\fR set on that platform). |
594 | .ie n .IP """EVBACKEND_POLL"" (value 2, poll backend, available everywhere except on windows)" 4 |
605 | .ie n .IP """EVBACKEND_POLL"" (value 2, poll backend, available everywhere except on windows)" 4 |
595 | .el .IP "\f(CWEVBACKEND_POLL\fR (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 |
596 | .IX Item "EVBACKEND_POLL (value 2, poll backend, available everywhere except on windows)" |
607 | .IX Item "EVBACKEND_POLL (value 2, poll backend, available everywhere except on windows)" |
597 | And this is your standard \fIpoll\fR\|(2) backend. It's more complicated |
608 | And this is your standard \fIpoll\fR\|(2) backend. It's more complicated |
598 | than select, but handles sparse fds better and has no artificial |
609 | than select, but handles sparse fds better and has no artificial |
599 | limit on the number of fds you can use (except it will slow down |
610 | limit on the number of fds you can use (except it will slow down |
600 | considerably with a lot of inactive fds). It scales similarly to select, |
611 | considerably with a lot of inactive fds). It scales similarly to select, |
601 | i.e. O(total_fds). See the entry for \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR, above, for |
612 | i.e. O(total_fds). See the entry for \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR, above, for |
… | |
… | |
603 | .Sp |
614 | .Sp |
604 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR to \f(CW\*(C`POLLIN | POLLERR | POLLHUP\*(C'\fR, and |
615 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR to \f(CW\*(C`POLLIN | POLLERR | POLLHUP\*(C'\fR, and |
605 | \&\f(CW\*(C`EV_WRITE\*(C'\fR to \f(CW\*(C`POLLOUT | POLLERR | POLLHUP\*(C'\fR. |
616 | \&\f(CW\*(C`EV_WRITE\*(C'\fR to \f(CW\*(C`POLLOUT | POLLERR | POLLHUP\*(C'\fR. |
606 | .ie n .IP """EVBACKEND_EPOLL"" (value 4, Linux)" 4 |
617 | .ie n .IP """EVBACKEND_EPOLL"" (value 4, Linux)" 4 |
607 | .el .IP "\f(CWEVBACKEND_EPOLL\fR (value 4, Linux)" 4 |
618 | .el .IP "\f(CWEVBACKEND_EPOLL\fR (value 4, Linux)" 4 |
608 | .IX Item "EVBACKEND_EPOLL (value 4, Linux)" |
619 | .IX Item "EVBACKEND_EPOLL (value 4, Linux)" |
609 | Use the linux-specific \fIepoll\fR\|(7) interface (for both pre\- and post\-2.6.9 |
620 | Use the linux-specific \fIepoll\fR\|(7) interface (for both pre\- and post\-2.6.9 |
610 | kernels). |
621 | kernels). |
611 | .Sp |
622 | .Sp |
612 | For few fds, this backend is a bit little slower than poll and select, but |
623 | For few fds, this backend is a bit little slower than poll and select, but |
613 | it scales phenomenally better. While poll and select usually scale like |
624 | it scales phenomenally better. While poll and select usually scale like |
… | |
… | |
666 | .Sp |
677 | .Sp |
667 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR and \f(CW\*(C`EV_WRITE\*(C'\fR in the same way as |
678 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR and \f(CW\*(C`EV_WRITE\*(C'\fR in the same way as |
668 | \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR. |
679 | \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR. |
669 | .ie n .IP """EVBACKEND_KQUEUE"" (value 8, most \s-1BSD\s0 clones)" 4 |
680 | .ie n .IP """EVBACKEND_KQUEUE"" (value 8, most \s-1BSD\s0 clones)" 4 |
670 | .el .IP "\f(CWEVBACKEND_KQUEUE\fR (value 8, most \s-1BSD\s0 clones)" 4 |
681 | .el .IP "\f(CWEVBACKEND_KQUEUE\fR (value 8, most \s-1BSD\s0 clones)" 4 |
671 | .IX Item "EVBACKEND_KQUEUE (value 8, most BSD clones)" |
682 | .IX Item "EVBACKEND_KQUEUE (value 8, most BSD clones)" |
672 | Kqueue deserves special mention, as at the time of this writing, it |
683 | Kqueue deserves special mention, as at the time of this writing, it |
673 | was broken on all BSDs except NetBSD (usually it doesn't work reliably |
684 | was broken on all BSDs except NetBSD (usually it doesn't work reliably |
674 | with anything but sockets and pipes, except on Darwin, where of course |
685 | with anything but sockets and pipes, except on Darwin, where of course |
675 | it's completely useless). Unlike epoll, however, whose brokenness |
686 | it's completely useless). Unlike epoll, however, whose brokenness |
676 | is by design, these kqueue bugs can (and eventually will) be fixed |
687 | is by design, these kqueue bugs can (and eventually will) be fixed |
… | |
… | |
687 | kernel is more efficient (which says nothing about its actual speed, of |
698 | kernel is more efficient (which says nothing about its actual speed, of |
688 | course). While stopping, setting and starting an I/O watcher does never |
699 | course). While stopping, setting and starting an I/O watcher does never |
689 | cause an extra system call as with \f(CW\*(C`EVBACKEND_EPOLL\*(C'\fR, it still adds up to |
700 | cause an extra system call as with \f(CW\*(C`EVBACKEND_EPOLL\*(C'\fR, it still adds up to |
690 | two event changes per incident. Support for \f(CW\*(C`fork ()\*(C'\fR is very bad (you |
701 | two event changes per incident. Support for \f(CW\*(C`fork ()\*(C'\fR is very bad (you |
691 | might have to leak fd's on fork, but it's more sane than epoll) and it |
702 | might have to leak fd's on fork, but it's more sane than epoll) and it |
692 | drops fds silently in similarly hard-to-detect cases |
703 | drops fds silently in similarly hard-to-detect cases. |
693 | .Sp |
704 | .Sp |
694 | This backend usually performs well under most conditions. |
705 | This backend usually performs well under most conditions. |
695 | .Sp |
706 | .Sp |
696 | While nominally embeddable in other event loops, this doesn't work |
707 | While nominally embeddable in other event loops, this doesn't work |
697 | everywhere, so you might need to test for this. And since it is broken |
708 | everywhere, so you might need to test for this. And since it is broken |
698 | almost everywhere, you should only use it when you have a lot of sockets |
709 | almost everywhere, you should only use it when you have a lot of sockets |
699 | (for which it usually works), by embedding it into another event loop |
710 | (for which it usually works), by embedding it into another event loop |
700 | (e.g. \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \f(CW\*(C`EVBACKEND_POLL\*(C'\fR (but \f(CW\*(C`poll\*(C'\fR is of course |
711 | (e.g. \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR or \f(CW\*(C`EVBACKEND_POLL\*(C'\fR (but \f(CW\*(C`poll\*(C'\fR is of course |
701 | also broken on \s-1OS\s0 X)) and, did I mention it, using it only for sockets. |
712 | also broken on \s-1OS X\s0)) and, did I mention it, using it only for sockets. |
702 | .Sp |
713 | .Sp |
703 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR into an \f(CW\*(C`EVFILT_READ\*(C'\fR kevent with |
714 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR into an \f(CW\*(C`EVFILT_READ\*(C'\fR kevent with |
704 | \&\f(CW\*(C`NOTE_EOF\*(C'\fR, and \f(CW\*(C`EV_WRITE\*(C'\fR into an \f(CW\*(C`EVFILT_WRITE\*(C'\fR kevent with |
715 | \&\f(CW\*(C`NOTE_EOF\*(C'\fR, and \f(CW\*(C`EV_WRITE\*(C'\fR into an \f(CW\*(C`EVFILT_WRITE\*(C'\fR kevent with |
705 | \&\f(CW\*(C`NOTE_EOF\*(C'\fR. |
716 | \&\f(CW\*(C`NOTE_EOF\*(C'\fR. |
706 | .ie n .IP """EVBACKEND_DEVPOLL"" (value 16, Solaris 8)" 4 |
717 | .ie n .IP """EVBACKEND_DEVPOLL"" (value 16, Solaris 8)" 4 |
… | |
… | |
710 | implementation). According to reports, \f(CW\*(C`/dev/poll\*(C'\fR only supports sockets |
721 | implementation). According to reports, \f(CW\*(C`/dev/poll\*(C'\fR only supports sockets |
711 | and is not embeddable, which would limit the usefulness of this backend |
722 | and is not embeddable, which would limit the usefulness of this backend |
712 | immensely. |
723 | immensely. |
713 | .ie n .IP """EVBACKEND_PORT"" (value 32, Solaris 10)" 4 |
724 | .ie n .IP """EVBACKEND_PORT"" (value 32, Solaris 10)" 4 |
714 | .el .IP "\f(CWEVBACKEND_PORT\fR (value 32, Solaris 10)" 4 |
725 | .el .IP "\f(CWEVBACKEND_PORT\fR (value 32, Solaris 10)" 4 |
715 | .IX Item "EVBACKEND_PORT (value 32, Solaris 10)" |
726 | .IX Item "EVBACKEND_PORT (value 32, Solaris 10)" |
716 | This uses the Solaris 10 event port mechanism. As with everything on Solaris, |
727 | This uses the Solaris 10 event port mechanism. As with everything on Solaris, |
717 | it's really slow, but it still scales very well (O(active_fds)). |
728 | it's really slow, but it still scales very well (O(active_fds)). |
718 | .Sp |
729 | .Sp |
719 | While this backend scales well, it requires one system call per active |
730 | While this backend scales well, it requires one system call per active |
720 | file descriptor per loop iteration. For small and medium numbers of file |
731 | file descriptor per loop iteration. For small and medium numbers of file |
… | |
… | |
799 | except in the rare occasion where you really need to free its resources. |
810 | except in the rare occasion where you really need to free its resources. |
800 | If you need dynamically allocated loops it is better to use \f(CW\*(C`ev_loop_new\*(C'\fR |
811 | If you need dynamically allocated loops it is better to use \f(CW\*(C`ev_loop_new\*(C'\fR |
801 | and \f(CW\*(C`ev_loop_destroy\*(C'\fR. |
812 | and \f(CW\*(C`ev_loop_destroy\*(C'\fR. |
802 | .IP "ev_loop_fork (loop)" 4 |
813 | .IP "ev_loop_fork (loop)" 4 |
803 | .IX Item "ev_loop_fork (loop)" |
814 | .IX Item "ev_loop_fork (loop)" |
804 | This function sets a flag that causes subsequent \f(CW\*(C`ev_run\*(C'\fR iterations to |
815 | This function sets a flag that causes subsequent \f(CW\*(C`ev_run\*(C'\fR iterations |
805 | reinitialise the kernel state for backends that have one. Despite the |
816 | to reinitialise the kernel state for backends that have one. Despite |
806 | name, you can call it anytime, but it makes most sense after forking, in |
817 | the name, you can call it anytime you are allowed to start or stop |
807 | the child process. You \fImust\fR call it (or use \f(CW\*(C`EVFLAG_FORKCHECK\*(C'\fR) in the |
818 | watchers (except inside an \f(CW\*(C`ev_prepare\*(C'\fR callback), but it makes most |
808 | child before resuming or calling \f(CW\*(C`ev_run\*(C'\fR. |
819 | sense after forking, in the child process. You \fImust\fR call it (or use |
|
|
820 | \&\f(CW\*(C`EVFLAG_FORKCHECK\*(C'\fR) in the child before resuming or calling \f(CW\*(C`ev_run\*(C'\fR. |
809 | .Sp |
821 | .Sp |
|
|
822 | In addition, if you want to reuse a loop (via this function or |
|
|
823 | \&\f(CW\*(C`EVFLAG_FORKCHECK\*(C'\fR), you \fIalso\fR have to ignore \f(CW\*(C`SIGPIPE\*(C'\fR. |
|
|
824 | .Sp |
810 | Again, you \fIhave\fR to call it on \fIany\fR loop that you want to re-use after |
825 | Again, you \fIhave\fR to call it on \fIany\fR loop that you want to re-use after |
811 | a fork, \fIeven if you do not plan to use the loop in the parent\fR. This is |
826 | a fork, \fIeven if you do not plan to use the loop in the parent\fR. This is |
812 | because some kernel interfaces *cough* \fIkqueue\fR *cough* do funny things |
827 | because some kernel interfaces *cough* \fIkqueue\fR *cough* do funny things |
813 | during fork. |
828 | during fork. |
814 | .Sp |
829 | .Sp |
815 | On the other hand, you only need to call this function in the child |
830 | On the other hand, you only need to call this function in the child |
… | |
… | |
1352 | example it might indicate that a fd is readable or writable, and if your |
1367 | example it might indicate that a fd is readable or writable, and if your |
1353 | callbacks is well-written it can just attempt the operation and cope with |
1368 | callbacks is well-written it can just attempt the operation and cope with |
1354 | the error from \fIread()\fR or \fIwrite()\fR. This will not work in multi-threaded |
1369 | the error from \fIread()\fR or \fIwrite()\fR. This will not work in multi-threaded |
1355 | programs, though, as the fd could already be closed and reused for another |
1370 | programs, though, as the fd could already be closed and reused for another |
1356 | thing, so beware. |
1371 | thing, so beware. |
1357 | .SS "\s-1GENERIC\s0 \s-1WATCHER\s0 \s-1FUNCTIONS\s0" |
1372 | .SS "\s-1GENERIC WATCHER FUNCTIONS\s0" |
1358 | .IX Subsection "GENERIC WATCHER FUNCTIONS" |
1373 | .IX Subsection "GENERIC WATCHER FUNCTIONS" |
1359 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
1374 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
1360 | .el .IP "\f(CWev_init\fR (ev_TYPE *watcher, callback)" 4 |
1375 | .el .IP "\f(CWev_init\fR (ev_TYPE *watcher, callback)" 4 |
1361 | .IX Item "ev_init (ev_TYPE *watcher, callback)" |
1376 | .IX Item "ev_init (ev_TYPE *watcher, callback)" |
1362 | This macro initialises the generic portion of a watcher. The contents |
1377 | This macro initialises the generic portion of a watcher. The contents |
… | |
… | |
1470 | or might not have been clamped to the valid range. |
1485 | or might not have been clamped to the valid range. |
1471 | .Sp |
1486 | .Sp |
1472 | The default priority used by watchers when no priority has been set is |
1487 | The default priority used by watchers when no priority has been set is |
1473 | always \f(CW0\fR, which is supposed to not be too high and not be too low :). |
1488 | always \f(CW0\fR, which is supposed to not be too high and not be too low :). |
1474 | .Sp |
1489 | .Sp |
1475 | See \*(L"\s-1WATCHER\s0 \s-1PRIORITY\s0 \s-1MODELS\s0\*(R", below, for a more thorough treatment of |
1490 | See \*(L"\s-1WATCHER PRIORITY MODELS\*(R"\s0, below, for a more thorough treatment of |
1476 | priorities. |
1491 | priorities. |
1477 | .IP "ev_invoke (loop, ev_TYPE *watcher, int revents)" 4 |
1492 | .IP "ev_invoke (loop, ev_TYPE *watcher, int revents)" 4 |
1478 | .IX Item "ev_invoke (loop, ev_TYPE *watcher, int revents)" |
1493 | .IX Item "ev_invoke (loop, ev_TYPE *watcher, int revents)" |
1479 | Invoke the \f(CW\*(C`watcher\*(C'\fR with the given \f(CW\*(C`loop\*(C'\fR and \f(CW\*(C`revents\*(C'\fR. Neither |
1494 | Invoke the \f(CW\*(C`watcher\*(C'\fR with the given \f(CW\*(C`loop\*(C'\fR and \f(CW\*(C`revents\*(C'\fR. Neither |
1480 | \&\f(CW\*(C`loop\*(C'\fR nor \f(CW\*(C`revents\*(C'\fR need to be valid as long as the watcher callback |
1495 | \&\f(CW\*(C`loop\*(C'\fR nor \f(CW\*(C`revents\*(C'\fR need to be valid as long as the watcher callback |
… | |
… | |
1500 | not started in the first place. |
1515 | not started in the first place. |
1501 | .Sp |
1516 | .Sp |
1502 | See also \f(CW\*(C`ev_feed_fd_event\*(C'\fR and \f(CW\*(C`ev_feed_signal_event\*(C'\fR for related |
1517 | See also \f(CW\*(C`ev_feed_fd_event\*(C'\fR and \f(CW\*(C`ev_feed_signal_event\*(C'\fR for related |
1503 | functions that do not need a watcher. |
1518 | functions that do not need a watcher. |
1504 | .PP |
1519 | .PP |
1505 | See also the \*(L"\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0\*(R" and \*(L"\s-1BUILDING\s0 \s-1YOUR\s0 |
1520 | See also the \*(L"\s-1ASSOCIATING CUSTOM DATA WITH A WATCHER\*(R"\s0 and \*(L"\s-1BUILDING YOUR |
1506 | \&\s-1OWN\s0 \s-1COMPOSITE\s0 \s-1WATCHERS\s0\*(R" idioms. |
1521 | OWN COMPOSITE WATCHERS\*(R"\s0 idioms. |
1507 | .SS "\s-1WATCHER\s0 \s-1STATES\s0" |
1522 | .SS "\s-1WATCHER STATES\s0" |
1508 | .IX Subsection "WATCHER STATES" |
1523 | .IX Subsection "WATCHER STATES" |
1509 | There are various watcher states mentioned throughout this manual \- |
1524 | There are various watcher states mentioned throughout this manual \- |
1510 | active, pending and so on. In this section these states and the rules to |
1525 | active, pending and so on. In this section these states and the rules to |
1511 | transition between them will be described in more detail \- and while these |
1526 | transition between them will be described in more detail \- and while these |
1512 | rules might look complicated, they usually do \*(L"the right thing\*(R". |
1527 | rules might look complicated, they usually do \*(L"the right thing\*(R". |
1513 | .IP "initialiased" 4 |
1528 | .IP "initialised" 4 |
1514 | .IX Item "initialiased" |
1529 | .IX Item "initialised" |
1515 | Before a watcher can be registered with the event loop it has to be |
1530 | Before a watcher can be registered with the event loop it has to be |
1516 | initialised. This can be done with a call to \f(CW\*(C`ev_TYPE_init\*(C'\fR, or calls to |
1531 | initialised. This can be done with a call to \f(CW\*(C`ev_TYPE_init\*(C'\fR, or calls to |
1517 | \&\f(CW\*(C`ev_init\*(C'\fR followed by the watcher-specific \f(CW\*(C`ev_TYPE_set\*(C'\fR function. |
1532 | \&\f(CW\*(C`ev_init\*(C'\fR followed by the watcher-specific \f(CW\*(C`ev_TYPE_set\*(C'\fR function. |
1518 | .Sp |
1533 | .Sp |
1519 | In this state it is simply some block of memory that is suitable for |
1534 | In this state it is simply some block of memory that is suitable for |
… | |
… | |
1555 | .Sp |
1570 | .Sp |
1556 | While stopped (and not pending) the watcher is essentially in the |
1571 | While stopped (and not pending) the watcher is essentially in the |
1557 | initialised state, that is, it can be reused, moved, modified in any way |
1572 | initialised state, that is, it can be reused, moved, modified in any way |
1558 | you wish (but when you trash the memory block, you need to \f(CW\*(C`ev_TYPE_init\*(C'\fR |
1573 | you wish (but when you trash the memory block, you need to \f(CW\*(C`ev_TYPE_init\*(C'\fR |
1559 | it again). |
1574 | it again). |
1560 | .SS "\s-1WATCHER\s0 \s-1PRIORITY\s0 \s-1MODELS\s0" |
1575 | .SS "\s-1WATCHER PRIORITY MODELS\s0" |
1561 | .IX Subsection "WATCHER PRIORITY MODELS" |
1576 | .IX Subsection "WATCHER PRIORITY MODELS" |
1562 | Many event loops support \fIwatcher priorities\fR, which are usually small |
1577 | Many event loops support \fIwatcher priorities\fR, which are usually small |
1563 | integers that influence the ordering of event callback invocation |
1578 | integers that influence the ordering of event callback invocation |
1564 | between watchers in some way, all else being equal. |
1579 | between watchers in some way, all else being equal. |
1565 | .PP |
1580 | .PP |
… | |
… | |
1763 | wish to read \- you would first have to request some data. |
1778 | wish to read \- you would first have to request some data. |
1764 | .PP |
1779 | .PP |
1765 | Since files are typically not-so-well supported by advanced notification |
1780 | Since files are typically not-so-well supported by advanced notification |
1766 | mechanism, libev tries hard to emulate \s-1POSIX\s0 behaviour with respect |
1781 | mechanism, libev tries hard to emulate \s-1POSIX\s0 behaviour with respect |
1767 | to files, even though you should not use it. The reason for this is |
1782 | to files, even though you should not use it. The reason for this is |
1768 | convenience: sometimes you want to watch \s-1STDIN\s0 or \s-1STDOUT\s0, which is |
1783 | convenience: sometimes you want to watch \s-1STDIN\s0 or \s-1STDOUT,\s0 which is |
1769 | usually a tty, often a pipe, but also sometimes files or special devices |
1784 | usually a tty, often a pipe, but also sometimes files or special devices |
1770 | (for example, \f(CW\*(C`epoll\*(C'\fR on Linux works with \fI/dev/random\fR but not with |
1785 | (for example, \f(CW\*(C`epoll\*(C'\fR on Linux works with \fI/dev/random\fR but not with |
1771 | \&\fI/dev/urandom\fR), and even though the file might better be served with |
1786 | \&\fI/dev/urandom\fR), and even though the file might better be served with |
1772 | asynchronous I/O instead of with non-blocking I/O, it is still useful when |
1787 | asynchronous I/O instead of with non-blocking I/O, it is still useful when |
1773 | it \*(L"just works\*(R" instead of freezing. |
1788 | it \*(L"just works\*(R" instead of freezing. |
1774 | .PP |
1789 | .PP |
1775 | So avoid file descriptors pointing to files when you know it (e.g. use |
1790 | So avoid file descriptors pointing to files when you know it (e.g. use |
1776 | libeio), but use them when it is convenient, e.g. for \s-1STDIN/STDOUT\s0, or |
1791 | libeio), but use them when it is convenient, e.g. for \s-1STDIN/STDOUT,\s0 or |
1777 | when you rarely read from a file instead of from a socket, and want to |
1792 | when you rarely read from a file instead of from a socket, and want to |
1778 | reuse the same code path. |
1793 | reuse the same code path. |
1779 | .PP |
1794 | .PP |
1780 | \fIThe special problem of fork\fR |
1795 | \fIThe special problem of fork\fR |
1781 | .IX Subsection "The special problem of fork" |
1796 | .IX Subsection "The special problem of fork" |
… | |
… | |
1791 | \fIThe special problem of \s-1SIGPIPE\s0\fR |
1806 | \fIThe special problem of \s-1SIGPIPE\s0\fR |
1792 | .IX Subsection "The special problem of SIGPIPE" |
1807 | .IX Subsection "The special problem of SIGPIPE" |
1793 | .PP |
1808 | .PP |
1794 | While not really specific to libev, it is easy to forget about \f(CW\*(C`SIGPIPE\*(C'\fR: |
1809 | While not really specific to libev, it is easy to forget about \f(CW\*(C`SIGPIPE\*(C'\fR: |
1795 | when writing to a pipe whose other end has been closed, your program gets |
1810 | when writing to a pipe whose other end has been closed, your program gets |
1796 | sent a \s-1SIGPIPE\s0, which, by default, aborts your program. For most programs |
1811 | sent a \s-1SIGPIPE,\s0 which, by default, aborts your program. For most programs |
1797 | this is sensible behaviour, for daemons, this is usually undesirable. |
1812 | this is sensible behaviour, for daemons, this is usually undesirable. |
1798 | .PP |
1813 | .PP |
1799 | So when you encounter spurious, unexplained daemon exits, make sure you |
1814 | So when you encounter spurious, unexplained daemon exits, make sure you |
1800 | ignore \s-1SIGPIPE\s0 (and maybe make sure you log the exit status of your daemon |
1815 | ignore \s-1SIGPIPE \s0(and maybe make sure you log the exit status of your daemon |
1801 | somewhere, as that would have given you a big clue). |
1816 | somewhere, as that would have given you a big clue). |
1802 | .PP |
1817 | .PP |
1803 | \fIThe special problem of \fIaccept()\fIing when you can't\fR |
1818 | \fIThe special problem of \fIaccept()\fIing when you can't\fR |
1804 | .IX Subsection "The special problem of accept()ing when you can't" |
1819 | .IX Subsection "The special problem of accept()ing when you can't" |
1805 | .PP |
1820 | .PP |
1806 | Many implementations of the \s-1POSIX\s0 \f(CW\*(C`accept\*(C'\fR function (for example, |
1821 | Many implementations of the \s-1POSIX \s0\f(CW\*(C`accept\*(C'\fR function (for example, |
1807 | found in post\-2004 Linux) have the peculiar behaviour of not removing a |
1822 | found in post\-2004 Linux) have the peculiar behaviour of not removing a |
1808 | connection from the pending queue in all error cases. |
1823 | connection from the pending queue in all error cases. |
1809 | .PP |
1824 | .PP |
1810 | For example, larger servers often run out of file descriptors (because |
1825 | For example, larger servers often run out of file descriptors (because |
1811 | of resource limits), causing \f(CW\*(C`accept\*(C'\fR to fail with \f(CW\*(C`ENFILE\*(C'\fR but not |
1826 | of resource limits), causing \f(CW\*(C`accept\*(C'\fR to fail with \f(CW\*(C`ENFILE\*(C'\fR but not |
… | |
… | |
2150 | .PP |
2165 | .PP |
2151 | The relative timeouts are calculated relative to the \f(CW\*(C`ev_now ()\*(C'\fR |
2166 | The relative timeouts are calculated relative to the \f(CW\*(C`ev_now ()\*(C'\fR |
2152 | time. This is usually the right thing as this timestamp refers to the time |
2167 | time. This is usually the right thing as this timestamp refers to the time |
2153 | of the event triggering whatever timeout you are modifying/starting. If |
2168 | of the event triggering whatever timeout you are modifying/starting. If |
2154 | you suspect event processing to be delayed and you \fIneed\fR to base the |
2169 | you suspect event processing to be delayed and you \fIneed\fR to base the |
2155 | timeout on the current time, use something like this to adjust for this: |
2170 | timeout on the current time, use something like the following to adjust |
|
|
2171 | for it: |
2156 | .PP |
2172 | .PP |
2157 | .Vb 1 |
2173 | .Vb 1 |
2158 | \& ev_timer_set (&timer, after + ev_now () \- ev_time (), 0.); |
2174 | \& ev_timer_set (&timer, after + (ev_time () \- ev_now ()), 0.); |
2159 | .Ve |
2175 | .Ve |
2160 | .PP |
2176 | .PP |
2161 | If the event loop is suspended for a long time, you can also force an |
2177 | If the event loop is suspended for a long time, you can also force an |
2162 | update of the time returned by \f(CW\*(C`ev_now ()\*(C'\fR by calling \f(CW\*(C`ev_now_update |
2178 | update of the time returned by \f(CW\*(C`ev_now ()\*(C'\fR by calling \f(CW\*(C`ev_now_update |
2163 | ()\*(C'\fR. |
2179 | ()\*(C'\fR, although that will push the event time of all outstanding events |
|
|
2180 | further into the future. |
2164 | .PP |
2181 | .PP |
2165 | \fIThe special problem of unsynchronised clocks\fR |
2182 | \fIThe special problem of unsynchronised clocks\fR |
2166 | .IX Subsection "The special problem of unsynchronised clocks" |
2183 | .IX Subsection "The special problem of unsynchronised clocks" |
2167 | .PP |
2184 | .PP |
2168 | Modern systems have a variety of clocks \- libev itself uses the normal |
2185 | Modern systems have a variety of clocks \- libev itself uses the normal |
… | |
… | |
2329 | Periodic watchers are also timers of a kind, but they are very versatile |
2346 | Periodic watchers are also timers of a kind, but they are very versatile |
2330 | (and unfortunately a bit complex). |
2347 | (and unfortunately a bit complex). |
2331 | .PP |
2348 | .PP |
2332 | Unlike \f(CW\*(C`ev_timer\*(C'\fR, periodic watchers are not based on real time (or |
2349 | Unlike \f(CW\*(C`ev_timer\*(C'\fR, periodic watchers are not based on real time (or |
2333 | relative time, the physical time that passes) but on wall clock time |
2350 | relative time, the physical time that passes) but on wall clock time |
2334 | (absolute time, the thing you can read on your calender or clock). The |
2351 | (absolute time, the thing you can read on your calendar or clock). The |
2335 | difference is that wall clock time can run faster or slower than real |
2352 | difference is that wall clock time can run faster or slower than real |
2336 | time, and time jumps are not uncommon (e.g. when you adjust your |
2353 | time, and time jumps are not uncommon (e.g. when you adjust your |
2337 | wrist-watch). |
2354 | wrist-watch). |
2338 | .PP |
2355 | .PP |
2339 | You can tell a periodic watcher to trigger after some specific point |
2356 | You can tell a periodic watcher to trigger after some specific point |
… | |
… | |
2416 | In this mode the values for \f(CW\*(C`interval\*(C'\fR and \f(CW\*(C`offset\*(C'\fR are both being |
2433 | In this mode the values for \f(CW\*(C`interval\*(C'\fR and \f(CW\*(C`offset\*(C'\fR are both being |
2417 | ignored. Instead, each time the periodic watcher gets scheduled, the |
2434 | ignored. Instead, each time the periodic watcher gets scheduled, the |
2418 | reschedule callback will be called with the watcher as first, and the |
2435 | reschedule callback will be called with the watcher as first, and the |
2419 | current time as second argument. |
2436 | current time as second argument. |
2420 | .Sp |
2437 | .Sp |
2421 | \&\s-1NOTE:\s0 \fIThis callback \s-1MUST\s0 \s-1NOT\s0 stop or destroy any periodic watcher, ever, |
2438 | \&\s-1NOTE: \s0\fIThis callback \s-1MUST NOT\s0 stop or destroy any periodic watcher, ever, |
2422 | or make \s-1ANY\s0 other event loop modifications whatsoever, unless explicitly |
2439 | or make \s-1ANY\s0 other event loop modifications whatsoever, unless explicitly |
2423 | allowed by documentation here\fR. |
2440 | allowed by documentation here\fR. |
2424 | .Sp |
2441 | .Sp |
2425 | If you need to stop it, return \f(CW\*(C`now + 1e30\*(C'\fR (or so, fudge fudge) and stop |
2442 | If you need to stop it, return \f(CW\*(C`now + 1e30\*(C'\fR (or so, fudge fudge) and stop |
2426 | it afterwards (e.g. by starting an \f(CW\*(C`ev_prepare\*(C'\fR watcher, which is the |
2443 | it afterwards (e.g. by starting an \f(CW\*(C`ev_prepare\*(C'\fR watcher, which is the |
… | |
… | |
2440 | It must return the next time to trigger, based on the passed time value |
2457 | It must return the next time to trigger, based on the passed time value |
2441 | (that is, the lowest time value larger than to the second argument). It |
2458 | (that is, the lowest time value larger than to the second argument). It |
2442 | will usually be called just before the callback will be triggered, but |
2459 | will usually be called just before the callback will be triggered, but |
2443 | might be called at other times, too. |
2460 | might be called at other times, too. |
2444 | .Sp |
2461 | .Sp |
2445 | \&\s-1NOTE:\s0 \fIThis callback must always return a time that is higher than or |
2462 | \&\s-1NOTE: \s0\fIThis callback must always return a time that is higher than or |
2446 | equal to the passed \f(CI\*(C`now\*(C'\fI value\fR. |
2463 | equal to the passed \f(CI\*(C`now\*(C'\fI value\fR. |
2447 | .Sp |
2464 | .Sp |
2448 | This can be used to create very complex timers, such as a timer that |
2465 | This can be used to create very complex timers, such as a timer that |
2449 | triggers on \*(L"next midnight, local time\*(R". To do this, you would calculate the |
2466 | triggers on \*(L"next midnight, local time\*(R". To do this, you would calculate the |
2450 | next midnight after \f(CW\*(C`now\*(C'\fR and return the timestamp value for this. How |
2467 | next midnight after \f(CW\*(C`now\*(C'\fR and return the timestamp value for this. How |
… | |
… | |
2542 | only within the same loop, i.e. you can watch for \f(CW\*(C`SIGINT\*(C'\fR in your |
2559 | only within the same loop, i.e. you can watch for \f(CW\*(C`SIGINT\*(C'\fR in your |
2543 | default loop and for \f(CW\*(C`SIGIO\*(C'\fR in another loop, but you cannot watch for |
2560 | default loop and for \f(CW\*(C`SIGIO\*(C'\fR in another loop, but you cannot watch for |
2544 | \&\f(CW\*(C`SIGINT\*(C'\fR in both the default loop and another loop at the same time. At |
2561 | \&\f(CW\*(C`SIGINT\*(C'\fR in both the default loop and another loop at the same time. At |
2545 | the moment, \f(CW\*(C`SIGCHLD\*(C'\fR is permanently tied to the default loop. |
2562 | the moment, \f(CW\*(C`SIGCHLD\*(C'\fR is permanently tied to the default loop. |
2546 | .PP |
2563 | .PP |
2547 | When the first watcher gets started will libev actually register something |
2564 | Only after the first watcher for a signal is started will libev actually |
2548 | with the kernel (thus it coexists with your own signal handlers as long as |
2565 | register something with the kernel. It thus coexists with your own signal |
2549 | you don't register any with libev for the same signal). |
2566 | handlers as long as you don't register any with libev for the same signal. |
2550 | .PP |
2567 | .PP |
2551 | If possible and supported, libev will install its handlers with |
2568 | If possible and supported, libev will install its handlers with |
2552 | \&\f(CW\*(C`SA_RESTART\*(C'\fR (or equivalent) behaviour enabled, so system calls should |
2569 | \&\f(CW\*(C`SA_RESTART\*(C'\fR (or equivalent) behaviour enabled, so system calls should |
2553 | not be unduly interrupted. If you have a problem with system calls getting |
2570 | not be unduly interrupted. If you have a problem with system calls getting |
2554 | interrupted by signals you can block all signals in an \f(CW\*(C`ev_check\*(C'\fR watcher |
2571 | interrupted by signals you can block all signals in an \f(CW\*(C`ev_check\*(C'\fR watcher |
… | |
… | |
2575 | The simplest way to ensure that the signal mask is reset in the child is |
2592 | The simplest way to ensure that the signal mask is reset in the child is |
2576 | to install a fork handler with \f(CW\*(C`pthread_atfork\*(C'\fR that resets it. That will |
2593 | to install a fork handler with \f(CW\*(C`pthread_atfork\*(C'\fR that resets it. That will |
2577 | catch fork calls done by libraries (such as the libc) as well. |
2594 | catch fork calls done by libraries (such as the libc) as well. |
2578 | .PP |
2595 | .PP |
2579 | In current versions of libev, the signal will not be blocked indefinitely |
2596 | In current versions of libev, the signal will not be blocked indefinitely |
2580 | unless you use the \f(CW\*(C`signalfd\*(C'\fR \s-1API\s0 (\f(CW\*(C`EV_SIGNALFD\*(C'\fR). While this reduces |
2597 | unless you use the \f(CW\*(C`signalfd\*(C'\fR \s-1API \s0(\f(CW\*(C`EV_SIGNALFD\*(C'\fR). While this reduces |
2581 | the window of opportunity for problems, it will not go away, as libev |
2598 | the window of opportunity for problems, it will not go away, as libev |
2582 | \&\fIhas\fR to modify the signal mask, at least temporarily. |
2599 | \&\fIhas\fR to modify the signal mask, at least temporarily. |
2583 | .PP |
2600 | .PP |
2584 | So I can't stress this enough: \fIIf you do not reset your signal mask when |
2601 | So I can't stress this enough: \fIIf you do not reset your signal mask when |
2585 | you expect it to be empty, you have a race condition in your code\fR. This |
2602 | you expect it to be empty, you have a race condition in your code\fR. This |
… | |
… | |
2615 | The signal the watcher watches out for. |
2632 | The signal the watcher watches out for. |
2616 | .PP |
2633 | .PP |
2617 | \fIExamples\fR |
2634 | \fIExamples\fR |
2618 | .IX Subsection "Examples" |
2635 | .IX Subsection "Examples" |
2619 | .PP |
2636 | .PP |
2620 | Example: Try to exit cleanly on \s-1SIGINT\s0. |
2637 | Example: Try to exit cleanly on \s-1SIGINT.\s0 |
2621 | .PP |
2638 | .PP |
2622 | .Vb 5 |
2639 | .Vb 5 |
2623 | \& static void |
2640 | \& static void |
2624 | \& sigint_cb (struct ev_loop *loop, ev_signal *w, int revents) |
2641 | \& sigint_cb (struct ev_loop *loop, ev_signal *w, int revents) |
2625 | \& { |
2642 | \& { |
… | |
… | |
2740 | .ie n .SS """ev_stat"" \- did the file attributes just change?" |
2757 | .ie n .SS """ev_stat"" \- did the file attributes just change?" |
2741 | .el .SS "\f(CWev_stat\fP \- did the file attributes just change?" |
2758 | .el .SS "\f(CWev_stat\fP \- did the file attributes just change?" |
2742 | .IX Subsection "ev_stat - did the file attributes just change?" |
2759 | .IX Subsection "ev_stat - did the file attributes just change?" |
2743 | This watches a file system path for attribute changes. That is, it calls |
2760 | This watches a file system path for attribute changes. That is, it calls |
2744 | \&\f(CW\*(C`stat\*(C'\fR on that path in regular intervals (or when the \s-1OS\s0 says it changed) |
2761 | \&\f(CW\*(C`stat\*(C'\fR on that path in regular intervals (or when the \s-1OS\s0 says it changed) |
2745 | and sees if it changed compared to the last time, invoking the callback if |
2762 | and sees if it changed compared to the last time, invoking the callback |
2746 | it did. |
2763 | if it did. Starting the watcher \f(CW\*(C`stat\*(C'\fR's the file, so only changes that |
|
|
2764 | happen after the watcher has been started will be reported. |
2747 | .PP |
2765 | .PP |
2748 | The path does not need to exist: changing from \*(L"path exists\*(R" to \*(L"path does |
2766 | The path does not need to exist: changing from \*(L"path exists\*(R" to \*(L"path does |
2749 | not exist\*(R" is a status change like any other. The condition \*(L"path does not |
2767 | not exist\*(R" is a status change like any other. The condition \*(L"path does not |
2750 | exist\*(R" (or more correctly \*(L"path cannot be stat'ed\*(R") is signified by the |
2768 | exist\*(R" (or more correctly \*(L"path cannot be stat'ed\*(R") is signified by the |
2751 | \&\f(CW\*(C`st_nlink\*(C'\fR field being zero (which is otherwise always forced to be at |
2769 | \&\f(CW\*(C`st_nlink\*(C'\fR field being zero (which is otherwise always forced to be at |
… | |
… | |
2781 | compilation environment, which means that on systems with large file |
2799 | compilation environment, which means that on systems with large file |
2782 | support disabled by default, you get the 32 bit version of the stat |
2800 | support disabled by default, you get the 32 bit version of the stat |
2783 | structure. When using the library from programs that change the \s-1ABI\s0 to |
2801 | structure. When using the library from programs that change the \s-1ABI\s0 to |
2784 | use 64 bit file offsets the programs will fail. In that case you have to |
2802 | use 64 bit file offsets the programs will fail. In that case you have to |
2785 | compile libev with the same flags to get binary compatibility. This is |
2803 | compile libev with the same flags to get binary compatibility. This is |
2786 | obviously the case with any flags that change the \s-1ABI\s0, but the problem is |
2804 | obviously the case with any flags that change the \s-1ABI,\s0 but the problem is |
2787 | most noticeably displayed with ev_stat and large file support. |
2805 | most noticeably displayed with ev_stat and large file support. |
2788 | .PP |
2806 | .PP |
2789 | The solution for this is to lobby your distribution maker to make large |
2807 | The solution for this is to lobby your distribution maker to make large |
2790 | file interfaces available by default (as e.g. FreeBSD does) and not |
2808 | file interfaces available by default (as e.g. FreeBSD does) and not |
2791 | optional. Libev cannot simply switch on large file support because it has |
2809 | optional. Libev cannot simply switch on large file support because it has |
… | |
… | |
3036 | .IX Subsection "ev_prepare and ev_check - customise your event loop!" |
3054 | .IX Subsection "ev_prepare and ev_check - customise your event loop!" |
3037 | Prepare and check watchers are often (but not always) used in pairs: |
3055 | Prepare and check watchers are often (but not always) used in pairs: |
3038 | prepare watchers get invoked before the process blocks and check watchers |
3056 | prepare watchers get invoked before the process blocks and check watchers |
3039 | afterwards. |
3057 | afterwards. |
3040 | .PP |
3058 | .PP |
3041 | You \fImust not\fR call \f(CW\*(C`ev_run\*(C'\fR or similar functions that enter |
3059 | You \fImust not\fR call \f(CW\*(C`ev_run\*(C'\fR (or similar functions that enter the |
3042 | the current event loop from either \f(CW\*(C`ev_prepare\*(C'\fR or \f(CW\*(C`ev_check\*(C'\fR |
3060 | current event loop) or \f(CW\*(C`ev_loop_fork\*(C'\fR from either \f(CW\*(C`ev_prepare\*(C'\fR or |
3043 | watchers. Other loops than the current one are fine, however. The |
3061 | \&\f(CW\*(C`ev_check\*(C'\fR watchers. Other loops than the current one are fine, |
3044 | rationale behind this is that you do not need to check for recursion in |
3062 | however. The rationale behind this is that you do not need to check |
3045 | those watchers, i.e. the sequence will always be \f(CW\*(C`ev_prepare\*(C'\fR, blocking, |
3063 | for recursion in those watchers, i.e. the sequence will always be |
3046 | \&\f(CW\*(C`ev_check\*(C'\fR so if you have one watcher of each kind they will always be |
3064 | \&\f(CW\*(C`ev_prepare\*(C'\fR, blocking, \f(CW\*(C`ev_check\*(C'\fR so if you have one watcher of each |
3047 | called in pairs bracketing the blocking call. |
3065 | kind they will always be called in pairs bracketing the blocking call. |
3048 | .PP |
3066 | .PP |
3049 | Their main purpose is to integrate other event mechanisms into libev and |
3067 | Their main purpose is to integrate other event mechanisms into libev and |
3050 | their use is somewhat advanced. They could be used, for example, to track |
3068 | their use is somewhat advanced. They could be used, for example, to track |
3051 | variable changes, implement your own watchers, integrate net-snmp or a |
3069 | variable changes, implement your own watchers, integrate net-snmp or a |
3052 | coroutine library and lots more. They are also occasionally useful if |
3070 | coroutine library and lots more. They are also occasionally useful if |
… | |
… | |
3222 | .Ve |
3240 | .Ve |
3223 | .PP |
3241 | .PP |
3224 | Method 4: Do not use a prepare or check watcher because the module you |
3242 | Method 4: Do not use a prepare or check watcher because the module you |
3225 | want to embed is not flexible enough to support it. Instead, you can |
3243 | want to embed is not flexible enough to support it. Instead, you can |
3226 | override their poll function. The drawback with this solution is that the |
3244 | override their poll function. The drawback with this solution is that the |
3227 | main loop is now no longer controllable by \s-1EV\s0. The \f(CW\*(C`Glib::EV\*(C'\fR module uses |
3245 | main loop is now no longer controllable by \s-1EV.\s0 The \f(CW\*(C`Glib::EV\*(C'\fR module uses |
3228 | this approach, effectively embedding \s-1EV\s0 as a client into the horrible |
3246 | this approach, effectively embedding \s-1EV\s0 as a client into the horrible |
3229 | libglib event loop. |
3247 | libglib event loop. |
3230 | .PP |
3248 | .PP |
3231 | .Vb 4 |
3249 | .Vb 4 |
3232 | \& static gint |
3250 | \& static gint |
… | |
… | |
3316 | \fIWatcher-Specific Functions and Data Members\fR |
3334 | \fIWatcher-Specific Functions and Data Members\fR |
3317 | .IX Subsection "Watcher-Specific Functions and Data Members" |
3335 | .IX Subsection "Watcher-Specific Functions and Data Members" |
3318 | .IP "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" 4 |
3336 | .IP "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" 4 |
3319 | .IX Item "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" |
3337 | .IX Item "ev_embed_init (ev_embed *, callback, struct ev_loop *embedded_loop)" |
3320 | .PD 0 |
3338 | .PD 0 |
3321 | .IP "ev_embed_set (ev_embed *, callback, struct ev_loop *embedded_loop)" 4 |
3339 | .IP "ev_embed_set (ev_embed *, struct ev_loop *embedded_loop)" 4 |
3322 | .IX Item "ev_embed_set (ev_embed *, callback, struct ev_loop *embedded_loop)" |
3340 | .IX Item "ev_embed_set (ev_embed *, struct ev_loop *embedded_loop)" |
3323 | .PD |
3341 | .PD |
3324 | Configures the watcher to embed the given loop, which must be |
3342 | Configures the watcher to embed the given loop, which must be |
3325 | embeddable. If the callback is \f(CW0\fR, then \f(CW\*(C`ev_embed_sweep\*(C'\fR will be |
3343 | embeddable. If the callback is \f(CW0\fR, then \f(CW\*(C`ev_embed_sweep\*(C'\fR will be |
3326 | invoked automatically, otherwise it is the responsibility of the callback |
3344 | invoked automatically, otherwise it is the responsibility of the callback |
3327 | to invoke it (it will continue to be called until the sweep has been done, |
3345 | to invoke it (it will continue to be called until the sweep has been done, |
… | |
… | |
3346 | .PP |
3364 | .PP |
3347 | .Vb 3 |
3365 | .Vb 3 |
3348 | \& struct ev_loop *loop_hi = ev_default_init (0); |
3366 | \& struct ev_loop *loop_hi = ev_default_init (0); |
3349 | \& struct ev_loop *loop_lo = 0; |
3367 | \& struct ev_loop *loop_lo = 0; |
3350 | \& ev_embed embed; |
3368 | \& ev_embed embed; |
3351 | \& |
3369 | \& |
3352 | \& // see if there is a chance of getting one that works |
3370 | \& // see if there is a chance of getting one that works |
3353 | \& // (remember that a flags value of 0 means autodetection) |
3371 | \& // (remember that a flags value of 0 means autodetection) |
3354 | \& loop_lo = ev_embeddable_backends () & ev_recommended_backends () |
3372 | \& loop_lo = ev_embeddable_backends () & ev_recommended_backends () |
3355 | \& ? ev_loop_new (ev_embeddable_backends () & ev_recommended_backends ()) |
3373 | \& ? ev_loop_new (ev_embeddable_backends () & ev_recommended_backends ()) |
3356 | \& : 0; |
3374 | \& : 0; |
… | |
… | |
3372 | .PP |
3390 | .PP |
3373 | .Vb 3 |
3391 | .Vb 3 |
3374 | \& struct ev_loop *loop = ev_default_init (0); |
3392 | \& struct ev_loop *loop = ev_default_init (0); |
3375 | \& struct ev_loop *loop_socket = 0; |
3393 | \& struct ev_loop *loop_socket = 0; |
3376 | \& ev_embed embed; |
3394 | \& ev_embed embed; |
3377 | \& |
3395 | \& |
3378 | \& if (ev_supported_backends () & ~ev_recommended_backends () & EVBACKEND_KQUEUE) |
3396 | \& if (ev_supported_backends () & ~ev_recommended_backends () & EVBACKEND_KQUEUE) |
3379 | \& if ((loop_socket = ev_loop_new (EVBACKEND_KQUEUE)) |
3397 | \& if ((loop_socket = ev_loop_new (EVBACKEND_KQUEUE)) |
3380 | \& { |
3398 | \& { |
3381 | \& ev_embed_init (&embed, 0, loop_socket); |
3399 | \& ev_embed_init (&embed, 0, loop_socket); |
3382 | \& ev_embed_start (loop, &embed); |
3400 | \& ev_embed_start (loop, &embed); |
… | |
… | |
3399 | of course. |
3417 | of course. |
3400 | .PP |
3418 | .PP |
3401 | \fIThe special problem of life after fork \- how is it possible?\fR |
3419 | \fIThe special problem of life after fork \- how is it possible?\fR |
3402 | .IX Subsection "The special problem of life after fork - how is it possible?" |
3420 | .IX Subsection "The special problem of life after fork - how is it possible?" |
3403 | .PP |
3421 | .PP |
3404 | Most uses of \f(CW\*(C`fork()\*(C'\fR consist of forking, then some simple calls to set |
3422 | Most uses of \f(CW\*(C`fork ()\*(C'\fR consist of forking, then some simple calls to set |
3405 | up/change the process environment, followed by a call to \f(CW\*(C`exec()\*(C'\fR. This |
3423 | up/change the process environment, followed by a call to \f(CW\*(C`exec()\*(C'\fR. This |
3406 | sequence should be handled by libev without any problems. |
3424 | sequence should be handled by libev without any problems. |
3407 | .PP |
3425 | .PP |
3408 | This changes when the application actually wants to do event handling |
3426 | This changes when the application actually wants to do event handling |
3409 | in the child, or both parent in child, in effect \*(L"continuing\*(R" after the |
3427 | in the child, or both parent in child, in effect \*(L"continuing\*(R" after the |
… | |
… | |
3649 | \&\f(CW\*(C`EV_ERROR\*(C'\fR, \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or \f(CW\*(C`EV_TIMER\*(C'\fR) and the \f(CW\*(C`arg\*(C'\fR |
3667 | \&\f(CW\*(C`EV_ERROR\*(C'\fR, \f(CW\*(C`EV_READ\*(C'\fR, \f(CW\*(C`EV_WRITE\*(C'\fR or \f(CW\*(C`EV_TIMER\*(C'\fR) and the \f(CW\*(C`arg\*(C'\fR |
3650 | value passed to \f(CW\*(C`ev_once\*(C'\fR. Note that it is possible to receive \fIboth\fR |
3668 | value passed to \f(CW\*(C`ev_once\*(C'\fR. Note that it is possible to receive \fIboth\fR |
3651 | a timeout and an io event at the same time \- you probably should give io |
3669 | a timeout and an io event at the same time \- you probably should give io |
3652 | events precedence. |
3670 | events precedence. |
3653 | .Sp |
3671 | .Sp |
3654 | Example: wait up to ten seconds for data to appear on \s-1STDIN_FILENO\s0. |
3672 | Example: wait up to ten seconds for data to appear on \s-1STDIN_FILENO.\s0 |
3655 | .Sp |
3673 | .Sp |
3656 | .Vb 7 |
3674 | .Vb 7 |
3657 | \& static void stdin_ready (int revents, void *arg) |
3675 | \& static void stdin_ready (int revents, void *arg) |
3658 | \& { |
3676 | \& { |
3659 | \& if (revents & EV_READ) |
3677 | \& if (revents & EV_READ) |
… | |
… | |
3675 | .SH "COMMON OR USEFUL IDIOMS (OR BOTH)" |
3693 | .SH "COMMON OR USEFUL IDIOMS (OR BOTH)" |
3676 | .IX Header "COMMON OR USEFUL IDIOMS (OR BOTH)" |
3694 | .IX Header "COMMON OR USEFUL IDIOMS (OR BOTH)" |
3677 | This section explains some common idioms that are not immediately |
3695 | This section explains some common idioms that are not immediately |
3678 | obvious. Note that examples are sprinkled over the whole manual, and this |
3696 | obvious. Note that examples are sprinkled over the whole manual, and this |
3679 | section only contains stuff that wouldn't fit anywhere else. |
3697 | section only contains stuff that wouldn't fit anywhere else. |
3680 | .SS "\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0" |
3698 | .SS "\s-1ASSOCIATING CUSTOM DATA WITH A WATCHER\s0" |
3681 | .IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER" |
3699 | .IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER" |
3682 | Each watcher has, by default, a \f(CW\*(C`void *data\*(C'\fR member that you can read |
3700 | Each watcher has, by default, a \f(CW\*(C`void *data\*(C'\fR member that you can read |
3683 | or modify at any time: libev will completely ignore it. This can be used |
3701 | or modify at any time: libev will completely ignore it. This can be used |
3684 | to associate arbitrary data with your watcher. If you need more data and |
3702 | to associate arbitrary data with your watcher. If you need more data and |
3685 | don't want to allocate memory separately and store a pointer to it in that |
3703 | don't want to allocate memory separately and store a pointer to it in that |
… | |
… | |
3711 | \& } |
3729 | \& } |
3712 | .Ve |
3730 | .Ve |
3713 | .PP |
3731 | .PP |
3714 | More interesting and less C\-conformant ways of casting your callback |
3732 | More interesting and less C\-conformant ways of casting your callback |
3715 | function type instead have been omitted. |
3733 | function type instead have been omitted. |
3716 | .SS "\s-1BUILDING\s0 \s-1YOUR\s0 \s-1OWN\s0 \s-1COMPOSITE\s0 \s-1WATCHERS\s0" |
3734 | .SS "\s-1BUILDING YOUR OWN COMPOSITE WATCHERS\s0" |
3717 | .IX Subsection "BUILDING YOUR OWN COMPOSITE WATCHERS" |
3735 | .IX Subsection "BUILDING YOUR OWN COMPOSITE WATCHERS" |
3718 | Another common scenario is to use some data structure with multiple |
3736 | Another common scenario is to use some data structure with multiple |
3719 | embedded watchers, in effect creating your own watcher that combines |
3737 | embedded watchers, in effect creating your own watcher that combines |
3720 | multiple libev event sources into one \*(L"super-watcher\*(R": |
3738 | multiple libev event sources into one \*(L"super-watcher\*(R": |
3721 | .PP |
3739 | .PP |
… | |
… | |
3749 | \& { |
3767 | \& { |
3750 | \& struct my_biggy big = (struct my_biggy *) |
3768 | \& struct my_biggy big = (struct my_biggy *) |
3751 | \& (((char *)w) \- offsetof (struct my_biggy, t2)); |
3769 | \& (((char *)w) \- offsetof (struct my_biggy, t2)); |
3752 | \& } |
3770 | \& } |
3753 | .Ve |
3771 | .Ve |
3754 | .SS "\s-1AVOIDING\s0 \s-1FINISHING\s0 \s-1BEFORE\s0 \s-1RETURNING\s0" |
3772 | .SS "\s-1AVOIDING FINISHING BEFORE RETURNING\s0" |
3755 | .IX Subsection "AVOIDING FINISHING BEFORE RETURNING" |
3773 | .IX Subsection "AVOIDING FINISHING BEFORE RETURNING" |
3756 | Often you have structures like this in event-based programs: |
3774 | Often you have structures like this in event-based programs: |
3757 | .PP |
3775 | .PP |
3758 | .Vb 4 |
3776 | .Vb 4 |
3759 | \& callback () |
3777 | \& callback () |
… | |
… | |
3781 | already been invoked. |
3799 | already been invoked. |
3782 | .PP |
3800 | .PP |
3783 | A common way around all these issues is to make sure that |
3801 | A common way around all these issues is to make sure that |
3784 | \&\f(CW\*(C`start_new_request\*(C'\fR \fIalways\fR returns before the callback is invoked. If |
3802 | \&\f(CW\*(C`start_new_request\*(C'\fR \fIalways\fR returns before the callback is invoked. If |
3785 | \&\f(CW\*(C`start_new_request\*(C'\fR immediately knows the result, it can artificially |
3803 | \&\f(CW\*(C`start_new_request\*(C'\fR immediately knows the result, it can artificially |
3786 | delay invoking the callback by e.g. using a \f(CW\*(C`prepare\*(C'\fR or \f(CW\*(C`idle\*(C'\fR watcher |
3804 | delay invoking the callback by using a \f(CW\*(C`prepare\*(C'\fR or \f(CW\*(C`idle\*(C'\fR watcher for |
3787 | for example, or more sneakily, by reusing an existing (stopped) watcher |
3805 | example, or more sneakily, by reusing an existing (stopped) watcher and |
3788 | and pushing it into the pending queue: |
3806 | pushing it into the pending queue: |
3789 | .PP |
3807 | .PP |
3790 | .Vb 2 |
3808 | .Vb 2 |
3791 | \& ev_set_cb (watcher, callback); |
3809 | \& ev_set_cb (watcher, callback); |
3792 | \& ev_feed_event (EV_A_ watcher, 0); |
3810 | \& ev_feed_event (EV_A_ watcher, 0); |
3793 | .Ve |
3811 | .Ve |
3794 | .PP |
3812 | .PP |
3795 | This way, \f(CW\*(C`start_new_request\*(C'\fR can safely return before the callback is |
3813 | This way, \f(CW\*(C`start_new_request\*(C'\fR can safely return before the callback is |
3796 | invoked, while not delaying callback invocation too much. |
3814 | invoked, while not delaying callback invocation too much. |
3797 | .SS "\s-1MODEL/NESTED\s0 \s-1EVENT\s0 \s-1LOOP\s0 \s-1INVOCATIONS\s0 \s-1AND\s0 \s-1EXIT\s0 \s-1CONDITIONS\s0" |
3815 | .SS "\s-1MODEL/NESTED EVENT LOOP INVOCATIONS AND EXIT CONDITIONS\s0" |
3798 | .IX Subsection "MODEL/NESTED EVENT LOOP INVOCATIONS AND EXIT CONDITIONS" |
3816 | .IX Subsection "MODEL/NESTED EVENT LOOP INVOCATIONS AND EXIT CONDITIONS" |
3799 | Often (especially in \s-1GUI\s0 toolkits) there are places where you have |
3817 | Often (especially in \s-1GUI\s0 toolkits) there are places where you have |
3800 | \&\fImodal\fR interaction, which is most easily implemented by recursively |
3818 | \&\fImodal\fR interaction, which is most easily implemented by recursively |
3801 | invoking \f(CW\*(C`ev_run\*(C'\fR. |
3819 | invoking \f(CW\*(C`ev_run\*(C'\fR. |
3802 | .PP |
3820 | .PP |
3803 | This brings the problem of exiting \- a callback might want to finish the |
3821 | This brings the problem of exiting \- a callback might want to finish the |
3804 | main \f(CW\*(C`ev_run\*(C'\fR call, but not the nested one (e.g. user clicked \*(L"Quit\*(R", but |
3822 | main \f(CW\*(C`ev_run\*(C'\fR call, but not the nested one (e.g. user clicked \*(L"Quit\*(R", but |
3805 | a modal \*(L"Are you sure?\*(R" dialog is still waiting), or just the nested one |
3823 | a modal \*(L"Are you sure?\*(R" dialog is still waiting), or just the nested one |
3806 | and not the main one (e.g. user clocked \*(L"Ok\*(R" in a modal dialog), or some |
3824 | and not the main one (e.g. user clocked \*(L"Ok\*(R" in a modal dialog), or some |
3807 | other combination: In these cases, \f(CW\*(C`ev_break\*(C'\fR will not work alone. |
3825 | other combination: In these cases, a simple \f(CW\*(C`ev_break\*(C'\fR will not work. |
3808 | .PP |
3826 | .PP |
3809 | The solution is to maintain \*(L"break this loop\*(R" variable for each \f(CW\*(C`ev_run\*(C'\fR |
3827 | The solution is to maintain \*(L"break this loop\*(R" variable for each \f(CW\*(C`ev_run\*(C'\fR |
3810 | invocation, and use a loop around \f(CW\*(C`ev_run\*(C'\fR until the condition is |
3828 | invocation, and use a loop around \f(CW\*(C`ev_run\*(C'\fR until the condition is |
3811 | triggered, using \f(CW\*(C`EVRUN_ONCE\*(C'\fR: |
3829 | triggered, using \f(CW\*(C`EVRUN_ONCE\*(C'\fR: |
3812 | .PP |
3830 | .PP |
… | |
… | |
3834 | \& exit_main_loop = 1; |
3852 | \& exit_main_loop = 1; |
3835 | \& |
3853 | \& |
3836 | \& // exit both |
3854 | \& // exit both |
3837 | \& exit_main_loop = exit_nested_loop = 1; |
3855 | \& exit_main_loop = exit_nested_loop = 1; |
3838 | .Ve |
3856 | .Ve |
3839 | .SS "\s-1THREAD\s0 \s-1LOCKING\s0 \s-1EXAMPLE\s0" |
3857 | .SS "\s-1THREAD LOCKING EXAMPLE\s0" |
3840 | .IX Subsection "THREAD LOCKING EXAMPLE" |
3858 | .IX Subsection "THREAD LOCKING EXAMPLE" |
3841 | Here is a fictitious example of how to run an event loop in a different |
3859 | Here is a fictitious example of how to run an event loop in a different |
3842 | thread from where callbacks are being invoked and watchers are |
3860 | thread from where callbacks are being invoked and watchers are |
3843 | created/added/removed. |
3861 | created/added/removed. |
3844 | .PP |
3862 | .PP |
… | |
… | |
3985 | .PP |
4003 | .PP |
3986 | Note that sending the \f(CW\*(C`ev_async\*(C'\fR watcher is required because otherwise |
4004 | Note that sending the \f(CW\*(C`ev_async\*(C'\fR watcher is required because otherwise |
3987 | an event loop currently blocking in the kernel will have no knowledge |
4005 | an event loop currently blocking in the kernel will have no knowledge |
3988 | about the newly added timer. By waking up the loop it will pick up any new |
4006 | about the newly added timer. By waking up the loop it will pick up any new |
3989 | watchers in the next event loop iteration. |
4007 | watchers in the next event loop iteration. |
3990 | .SS "\s-1THREADS\s0, \s-1COROUTINES\s0, \s-1CONTINUATIONS\s0, \s-1QUEUES\s0... \s-1INSTEAD\s0 \s-1OF\s0 \s-1CALLBACKS\s0" |
4008 | .SS "\s-1THREADS, COROUTINES, CONTINUATIONS, QUEUES... INSTEAD OF CALLBACKS\s0" |
3991 | .IX Subsection "THREADS, COROUTINES, CONTINUATIONS, QUEUES... INSTEAD OF CALLBACKS" |
4009 | .IX Subsection "THREADS, COROUTINES, CONTINUATIONS, QUEUES... INSTEAD OF CALLBACKS" |
3992 | While the overhead of a callback that e.g. schedules a thread is small, it |
4010 | While the overhead of a callback that e.g. schedules a thread is small, it |
3993 | is still an overhead. If you embed libev, and your main usage is with some |
4011 | is still an overhead. If you embed libev, and your main usage is with some |
3994 | kind of threads or coroutines, you might want to customise libev so that |
4012 | kind of threads or coroutines, you might want to customise libev so that |
3995 | doesn't need callbacks anymore. |
4013 | doesn't need callbacks anymore. |
… | |
… | |
4031 | You can do similar tricks if you have, say, threads with an event queue \- |
4049 | You can do similar tricks if you have, say, threads with an event queue \- |
4032 | instead of storing a coroutine, you store the queue object and instead of |
4050 | instead of storing a coroutine, you store the queue object and instead of |
4033 | switching to a coroutine, you push the watcher onto the queue and notify |
4051 | switching to a coroutine, you push the watcher onto the queue and notify |
4034 | any waiters. |
4052 | any waiters. |
4035 | .PP |
4053 | .PP |
4036 | To embed libev, see \*(L"\s-1EMBEDDING\s0\*(R", but in short, it's easiest to create two |
4054 | To embed libev, see \*(L"\s-1EMBEDDING\*(R"\s0, but in short, it's easiest to create two |
4037 | files, \fImy_ev.h\fR and \fImy_ev.c\fR that include the respective libev files: |
4055 | files, \fImy_ev.h\fR and \fImy_ev.c\fR that include the respective libev files: |
4038 | .PP |
4056 | .PP |
4039 | .Vb 4 |
4057 | .Vb 4 |
4040 | \& // my_ev.h |
4058 | \& // my_ev.h |
4041 | \& #define EV_CB_DECLARE(type) struct my_coro *cb; |
4059 | \& #define EV_CB_DECLARE(type) struct my_coro *cb; |
4042 | \& #define EV_CB_INVOKE(watcher) switch_to ((watcher)\->cb); |
4060 | \& #define EV_CB_INVOKE(watcher) switch_to ((watcher)\->cb) |
4043 | \& #include "../libev/ev.h" |
4061 | \& #include "../libev/ev.h" |
4044 | \& |
4062 | \& |
4045 | \& // my_ev.c |
4063 | \& // my_ev.c |
4046 | \& #define EV_H "my_ev.h" |
4064 | \& #define EV_H "my_ev.h" |
4047 | \& #include "../libev/ev.c" |
4065 | \& #include "../libev/ev.c" |
… | |
… | |
4233 | \& void operator() (ev::io &w, int revents) |
4251 | \& void operator() (ev::io &w, int revents) |
4234 | \& { |
4252 | \& { |
4235 | \& ... |
4253 | \& ... |
4236 | \& } |
4254 | \& } |
4237 | \& } |
4255 | \& } |
4238 | \& |
4256 | \& |
4239 | \& myfunctor f; |
4257 | \& myfunctor f; |
4240 | \& |
4258 | \& |
4241 | \& ev::io w; |
4259 | \& ev::io w; |
4242 | \& w.set (&f); |
4260 | \& w.set (&f); |
4243 | .Ve |
4261 | .Ve |
… | |
… | |
4336 | there are additional modules that implement libev-compatible interfaces |
4354 | there are additional modules that implement libev-compatible interfaces |
4337 | to \f(CW\*(C`libadns\*(C'\fR (\f(CW\*(C`EV::ADNS\*(C'\fR, but \f(CW\*(C`AnyEvent::DNS\*(C'\fR is preferred nowadays), |
4355 | to \f(CW\*(C`libadns\*(C'\fR (\f(CW\*(C`EV::ADNS\*(C'\fR, but \f(CW\*(C`AnyEvent::DNS\*(C'\fR is preferred nowadays), |
4338 | \&\f(CW\*(C`Net::SNMP\*(C'\fR (\f(CW\*(C`Net::SNMP::EV\*(C'\fR) and the \f(CW\*(C`libglib\*(C'\fR event core (\f(CW\*(C`Glib::EV\*(C'\fR |
4356 | \&\f(CW\*(C`Net::SNMP\*(C'\fR (\f(CW\*(C`Net::SNMP::EV\*(C'\fR) and the \f(CW\*(C`libglib\*(C'\fR event core (\f(CW\*(C`Glib::EV\*(C'\fR |
4339 | and \f(CW\*(C`EV::Glib\*(C'\fR). |
4357 | and \f(CW\*(C`EV::Glib\*(C'\fR). |
4340 | .Sp |
4358 | .Sp |
4341 | It can be found and installed via \s-1CPAN\s0, its homepage is at |
4359 | It can be found and installed via \s-1CPAN,\s0 its homepage is at |
4342 | <http://software.schmorp.de/pkg/EV>. |
4360 | <http://software.schmorp.de/pkg/EV>. |
4343 | .IP "Python" 4 |
4361 | .IP "Python" 4 |
4344 | .IX Item "Python" |
4362 | .IX Item "Python" |
4345 | Python bindings can be found at <http://code.google.com/p/pyev/>. It |
4363 | Python bindings can be found at <http://code.google.com/p/pyev/>. It |
4346 | seems to be quite complete and well-documented. |
4364 | seems to be quite complete and well-documented. |
… | |
… | |
4354 | Roger Pack reports that using the link order \f(CW\*(C`\-lws2_32 \-lmsvcrt\-ruby\-190\*(C'\fR |
4372 | Roger Pack reports that using the link order \f(CW\*(C`\-lws2_32 \-lmsvcrt\-ruby\-190\*(C'\fR |
4355 | makes rev work even on mingw. |
4373 | makes rev work even on mingw. |
4356 | .IP "Haskell" 4 |
4374 | .IP "Haskell" 4 |
4357 | .IX Item "Haskell" |
4375 | .IX Item "Haskell" |
4358 | A haskell binding to libev is available at |
4376 | A haskell binding to libev is available at |
4359 | http://hackage.haskell.org/cgi\-bin/hackage\-scripts/package/hlibev <http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hlibev>. |
4377 | <http://hackage.haskell.org/cgi\-bin/hackage\-scripts/package/hlibev>. |
4360 | .IP "D" 4 |
4378 | .IP "D" 4 |
4361 | .IX Item "D" |
4379 | .IX Item "D" |
4362 | Leandro Lucarella has written a D language binding (\fIev.d\fR) for libev, to |
4380 | Leandro Lucarella has written a D language binding (\fIev.d\fR) for libev, to |
4363 | be found at <http://www.llucax.com.ar/proj/ev.d/index.html>. |
4381 | be found at <http://www.llucax.com.ar/proj/ev.d/index.html>. |
4364 | .IP "Ocaml" 4 |
4382 | .IP "Ocaml" 4 |
4365 | .IX Item "Ocaml" |
4383 | .IX Item "Ocaml" |
4366 | Erkki Seppala has written Ocaml bindings for libev, to be found at |
4384 | Erkki Seppala has written Ocaml bindings for libev, to be found at |
4367 | http://modeemi.cs.tut.fi/~flux/software/ocaml\-ev/ <http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>. |
4385 | <http://modeemi.cs.tut.fi/~flux/software/ocaml\-ev/>. |
4368 | .IP "Lua" 4 |
4386 | .IP "Lua" 4 |
4369 | .IX Item "Lua" |
4387 | .IX Item "Lua" |
4370 | Brian Maher has written a partial interface to libev for lua (at the |
4388 | Brian Maher has written a partial interface to libev for lua (at the |
4371 | time of this writing, only \f(CW\*(C`ev_io\*(C'\fR and \f(CW\*(C`ev_timer\*(C'\fR), to be found at |
4389 | time of this writing, only \f(CW\*(C`ev_io\*(C'\fR and \f(CW\*(C`ev_timer\*(C'\fR), to be found at |
4372 | http://github.com/brimworks/lua\-ev <http://github.com/brimworks/lua-ev>. |
4390 | <http://github.com/brimworks/lua\-ev>. |
4373 | .IP "Javascript" 4 |
4391 | .IP "Javascript" 4 |
4374 | .IX Item "Javascript" |
4392 | .IX Item "Javascript" |
4375 | Node.js (<http://nodejs.org>) uses libev as the underlying event library. |
4393 | Node.js (<http://nodejs.org>) uses libev as the underlying event library. |
4376 | .IP "Others" 4 |
4394 | .IP "Others" 4 |
4377 | .IX Item "Others" |
4395 | .IX Item "Others" |
… | |
… | |
4466 | .SS "\s-1FILESETS\s0" |
4484 | .SS "\s-1FILESETS\s0" |
4467 | .IX Subsection "FILESETS" |
4485 | .IX Subsection "FILESETS" |
4468 | Depending on what features you need you need to include one or more sets of files |
4486 | Depending on what features you need you need to include one or more sets of files |
4469 | in your application. |
4487 | in your application. |
4470 | .PP |
4488 | .PP |
4471 | \fI\s-1CORE\s0 \s-1EVENT\s0 \s-1LOOP\s0\fR |
4489 | \fI\s-1CORE EVENT LOOP\s0\fR |
4472 | .IX Subsection "CORE EVENT LOOP" |
4490 | .IX Subsection "CORE EVENT LOOP" |
4473 | .PP |
4491 | .PP |
4474 | To include only the libev core (all the \f(CW\*(C`ev_*\*(C'\fR functions), with manual |
4492 | To include only the libev core (all the \f(CW\*(C`ev_*\*(C'\fR functions), with manual |
4475 | configuration (no autoconf): |
4493 | configuration (no autoconf): |
4476 | .PP |
4494 | .PP |
… | |
… | |
4479 | \& #include "ev.c" |
4497 | \& #include "ev.c" |
4480 | .Ve |
4498 | .Ve |
4481 | .PP |
4499 | .PP |
4482 | This will automatically include \fIev.h\fR, too, and should be done in a |
4500 | This will automatically include \fIev.h\fR, too, and should be done in a |
4483 | single C source file only to provide the function implementations. To use |
4501 | single C source file only to provide the function implementations. To use |
4484 | it, do the same for \fIev.h\fR in all files wishing to use this \s-1API\s0 (best |
4502 | it, do the same for \fIev.h\fR in all files wishing to use this \s-1API \s0(best |
4485 | done by writing a wrapper around \fIev.h\fR that you can include instead and |
4503 | done by writing a wrapper around \fIev.h\fR that you can include instead and |
4486 | where you can put other configuration options): |
4504 | where you can put other configuration options): |
4487 | .PP |
4505 | .PP |
4488 | .Vb 2 |
4506 | .Vb 2 |
4489 | \& #define EV_STANDALONE 1 |
4507 | \& #define EV_STANDALONE 1 |
… | |
… | |
4503 | \& ev_vars.h |
4521 | \& ev_vars.h |
4504 | \& ev_wrap.h |
4522 | \& ev_wrap.h |
4505 | \& |
4523 | \& |
4506 | \& ev_win32.c required on win32 platforms only |
4524 | \& ev_win32.c required on win32 platforms only |
4507 | \& |
4525 | \& |
4508 | \& ev_select.c only when select backend is enabled (which is enabled by default) |
4526 | \& ev_select.c only when select backend is enabled |
4509 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
4527 | \& ev_poll.c only when poll backend is enabled |
4510 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
4528 | \& ev_epoll.c only when the epoll backend is enabled |
4511 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
4529 | \& ev_kqueue.c only when the kqueue backend is enabled |
4512 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
4530 | \& ev_port.c only when the solaris port backend is enabled |
4513 | .Ve |
4531 | .Ve |
4514 | .PP |
4532 | .PP |
4515 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
4533 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
4516 | to compile this single file. |
4534 | to compile this single file. |
4517 | .PP |
4535 | .PP |
4518 | \fI\s-1LIBEVENT\s0 \s-1COMPATIBILITY\s0 \s-1API\s0\fR |
4536 | \fI\s-1LIBEVENT COMPATIBILITY API\s0\fR |
4519 | .IX Subsection "LIBEVENT COMPATIBILITY API" |
4537 | .IX Subsection "LIBEVENT COMPATIBILITY API" |
4520 | .PP |
4538 | .PP |
4521 | To include the libevent compatibility \s-1API\s0, also include: |
4539 | To include the libevent compatibility \s-1API,\s0 also include: |
4522 | .PP |
4540 | .PP |
4523 | .Vb 1 |
4541 | .Vb 1 |
4524 | \& #include "event.c" |
4542 | \& #include "event.c" |
4525 | .Ve |
4543 | .Ve |
4526 | .PP |
4544 | .PP |
… | |
… | |
4528 | .PP |
4546 | .PP |
4529 | .Vb 1 |
4547 | .Vb 1 |
4530 | \& #include "event.h" |
4548 | \& #include "event.h" |
4531 | .Ve |
4549 | .Ve |
4532 | .PP |
4550 | .PP |
4533 | in the files that want to use the libevent \s-1API\s0. This also includes \fIev.h\fR. |
4551 | in the files that want to use the libevent \s-1API.\s0 This also includes \fIev.h\fR. |
4534 | .PP |
4552 | .PP |
4535 | You need the following additional files for this: |
4553 | You need the following additional files for this: |
4536 | .PP |
4554 | .PP |
4537 | .Vb 2 |
4555 | .Vb 2 |
4538 | \& event.h |
4556 | \& event.h |
4539 | \& event.c |
4557 | \& event.c |
4540 | .Ve |
4558 | .Ve |
4541 | .PP |
4559 | .PP |
4542 | \fI\s-1AUTOCONF\s0 \s-1SUPPORT\s0\fR |
4560 | \fI\s-1AUTOCONF SUPPORT\s0\fR |
4543 | .IX Subsection "AUTOCONF SUPPORT" |
4561 | .IX Subsection "AUTOCONF SUPPORT" |
4544 | .PP |
4562 | .PP |
4545 | Instead of using \f(CW\*(C`EV_STANDALONE=1\*(C'\fR and providing your configuration in |
4563 | Instead of using \f(CW\*(C`EV_STANDALONE=1\*(C'\fR and providing your configuration in |
4546 | whatever way you want, you can also \f(CW\*(C`m4_include([libev.m4])\*(C'\fR in your |
4564 | whatever way you want, you can also \f(CW\*(C`m4_include([libev.m4])\*(C'\fR in your |
4547 | \&\fIconfigure.ac\fR and leave \f(CW\*(C`EV_STANDALONE\*(C'\fR undefined. \fIev.c\fR will then |
4565 | \&\fIconfigure.ac\fR and leave \f(CW\*(C`EV_STANDALONE\*(C'\fR undefined. \fIev.c\fR will then |
… | |
… | |
4550 | For this of course you need the m4 file: |
4568 | For this of course you need the m4 file: |
4551 | .PP |
4569 | .PP |
4552 | .Vb 1 |
4570 | .Vb 1 |
4553 | \& libev.m4 |
4571 | \& libev.m4 |
4554 | .Ve |
4572 | .Ve |
4555 | .SS "\s-1PREPROCESSOR\s0 \s-1SYMBOLS/MACROS\s0" |
4573 | .SS "\s-1PREPROCESSOR SYMBOLS/MACROS\s0" |
4556 | .IX Subsection "PREPROCESSOR SYMBOLS/MACROS" |
4574 | .IX Subsection "PREPROCESSOR SYMBOLS/MACROS" |
4557 | Libev can be configured via a variety of preprocessor symbols you have to |
4575 | Libev can be configured via a variety of preprocessor symbols you have to |
4558 | define before including (or compiling) any of its files. The default in |
4576 | define before including (or compiling) any of its files. The default in |
4559 | the absence of autoconf is documented for every option. |
4577 | the absence of autoconf is documented for every option. |
4560 | .PP |
4578 | .PP |
4561 | Symbols marked with \*(L"(h)\*(R" do not change the \s-1ABI\s0, and can have different |
4579 | Symbols marked with \*(L"(h)\*(R" do not change the \s-1ABI,\s0 and can have different |
4562 | values when compiling libev vs. including \fIev.h\fR, so it is permissible |
4580 | values when compiling libev vs. including \fIev.h\fR, so it is permissible |
4563 | to redefine them before including \fIev.h\fR without breaking compatibility |
4581 | to redefine them before including \fIev.h\fR without breaking compatibility |
4564 | to a compiled library. All other symbols change the \s-1ABI\s0, which means all |
4582 | to a compiled library. All other symbols change the \s-1ABI,\s0 which means all |
4565 | users of libev and the libev code itself must be compiled with compatible |
4583 | users of libev and the libev code itself must be compiled with compatible |
4566 | settings. |
4584 | settings. |
4567 | .IP "\s-1EV_COMPAT3\s0 (h)" 4 |
4585 | .IP "\s-1EV_COMPAT3 \s0(h)" 4 |
4568 | .IX Item "EV_COMPAT3 (h)" |
4586 | .IX Item "EV_COMPAT3 (h)" |
4569 | Backwards compatibility is a major concern for libev. This is why this |
4587 | Backwards compatibility is a major concern for libev. This is why this |
4570 | release of libev comes with wrappers for the functions and symbols that |
4588 | release of libev comes with wrappers for the functions and symbols that |
4571 | have been renamed between libev version 3 and 4. |
4589 | have been renamed between libev version 3 and 4. |
4572 | .Sp |
4590 | .Sp |
… | |
… | |
4577 | typedef in that case. |
4595 | typedef in that case. |
4578 | .Sp |
4596 | .Sp |
4579 | In some future version, the default for \f(CW\*(C`EV_COMPAT3\*(C'\fR will become \f(CW0\fR, |
4597 | In some future version, the default for \f(CW\*(C`EV_COMPAT3\*(C'\fR will become \f(CW0\fR, |
4580 | and in some even more future version the compatibility code will be |
4598 | and in some even more future version the compatibility code will be |
4581 | removed completely. |
4599 | removed completely. |
4582 | .IP "\s-1EV_STANDALONE\s0 (h)" 4 |
4600 | .IP "\s-1EV_STANDALONE \s0(h)" 4 |
4583 | .IX Item "EV_STANDALONE (h)" |
4601 | .IX Item "EV_STANDALONE (h)" |
4584 | Must always be \f(CW1\fR if you do not use autoconf configuration, which |
4602 | Must always be \f(CW1\fR if you do not use autoconf configuration, which |
4585 | keeps libev from including \fIconfig.h\fR, and it also defines dummy |
4603 | keeps libev from including \fIconfig.h\fR, and it also defines dummy |
4586 | implementations for some libevent functions (such as logging, which is not |
4604 | implementations for some libevent functions (such as logging, which is not |
4587 | supported). It will also not define any of the structs usually found in |
4605 | supported). It will also not define any of the structs usually found in |
… | |
… | |
4730 | between threads, that is, threads can be used, but threads never run on |
4748 | between threads, that is, threads can be used, but threads never run on |
4731 | different cpus (or different cpu cores). This reduces dependencies |
4749 | different cpus (or different cpu cores). This reduces dependencies |
4732 | and makes libev faster. |
4750 | and makes libev faster. |
4733 | .IP "\s-1EV_NO_THREADS\s0" 4 |
4751 | .IP "\s-1EV_NO_THREADS\s0" 4 |
4734 | .IX Item "EV_NO_THREADS" |
4752 | .IX Item "EV_NO_THREADS" |
4735 | If defined to be \f(CW1\fR, libev will assume that it will never be called |
4753 | If defined to be \f(CW1\fR, libev will assume that it will never be called from |
4736 | from different threads, which is a stronger assumption than \f(CW\*(C`EV_NO_SMP\*(C'\fR, |
4754 | different threads (that includes signal handlers), which is a stronger |
4737 | above. This reduces dependencies and makes libev faster. |
4755 | assumption than \f(CW\*(C`EV_NO_SMP\*(C'\fR, above. This reduces dependencies and makes |
|
|
4756 | libev faster. |
4738 | .IP "\s-1EV_ATOMIC_T\s0" 4 |
4757 | .IP "\s-1EV_ATOMIC_T\s0" 4 |
4739 | .IX Item "EV_ATOMIC_T" |
4758 | .IX Item "EV_ATOMIC_T" |
4740 | Libev requires an integer type (suitable for storing \f(CW0\fR or \f(CW1\fR) whose |
4759 | Libev requires an integer type (suitable for storing \f(CW0\fR or \f(CW1\fR) whose |
4741 | access is atomic with respect to other threads or signal contexts. No |
4760 | access is atomic with respect to other threads or signal contexts. No |
4742 | such type is easily found in the C language, so you can provide your own |
4761 | such type is easily found in the C language, so you can provide your own |
… | |
… | |
4744 | handler \*(L"locking\*(R" as well as for signal and thread safety in \f(CW\*(C`ev_async\*(C'\fR |
4763 | handler \*(L"locking\*(R" as well as for signal and thread safety in \f(CW\*(C`ev_async\*(C'\fR |
4745 | watchers. |
4764 | watchers. |
4746 | .Sp |
4765 | .Sp |
4747 | In the absence of this define, libev will use \f(CW\*(C`sig_atomic_t volatile\*(C'\fR |
4766 | In the absence of this define, libev will use \f(CW\*(C`sig_atomic_t volatile\*(C'\fR |
4748 | (from \fIsignal.h\fR), which is usually good enough on most platforms. |
4767 | (from \fIsignal.h\fR), which is usually good enough on most platforms. |
4749 | .IP "\s-1EV_H\s0 (h)" 4 |
4768 | .IP "\s-1EV_H \s0(h)" 4 |
4750 | .IX Item "EV_H (h)" |
4769 | .IX Item "EV_H (h)" |
4751 | The name of the \fIev.h\fR header file used to include it. The default if |
4770 | The name of the \fIev.h\fR header file used to include it. The default if |
4752 | undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be |
4771 | undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be |
4753 | used to virtually rename the \fIev.h\fR header file in case of conflicts. |
4772 | used to virtually rename the \fIev.h\fR header file in case of conflicts. |
4754 | .IP "\s-1EV_CONFIG_H\s0 (h)" 4 |
4773 | .IP "\s-1EV_CONFIG_H \s0(h)" 4 |
4755 | .IX Item "EV_CONFIG_H (h)" |
4774 | .IX Item "EV_CONFIG_H (h)" |
4756 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
4775 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
4757 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
4776 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
4758 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
4777 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
4759 | .IP "\s-1EV_EVENT_H\s0 (h)" 4 |
4778 | .IP "\s-1EV_EVENT_H \s0(h)" 4 |
4760 | .IX Item "EV_EVENT_H (h)" |
4779 | .IX Item "EV_EVENT_H (h)" |
4761 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
4780 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
4762 | of how the \fIevent.h\fR header can be found, the default is \f(CW"event.h"\fR. |
4781 | of how the \fIevent.h\fR header can be found, the default is \f(CW"event.h"\fR. |
4763 | .IP "\s-1EV_PROTOTYPES\s0 (h)" 4 |
4782 | .IP "\s-1EV_PROTOTYPES \s0(h)" 4 |
4764 | .IX Item "EV_PROTOTYPES (h)" |
4783 | .IX Item "EV_PROTOTYPES (h)" |
4765 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
4784 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
4766 | prototypes, but still define all the structs and other symbols. This is |
4785 | prototypes, but still define all the structs and other symbols. This is |
4767 | occasionally useful if you want to provide your own wrapper functions |
4786 | occasionally useful if you want to provide your own wrapper functions |
4768 | around libev functions. |
4787 | around libev functions. |
… | |
… | |
4792 | all the priorities, so having many of them (hundreds) uses a lot of space |
4811 | all the priorities, so having many of them (hundreds) uses a lot of space |
4793 | and time, so using the defaults of five priorities (\-2 .. +2) is usually |
4812 | and time, so using the defaults of five priorities (\-2 .. +2) is usually |
4794 | fine. |
4813 | fine. |
4795 | .Sp |
4814 | .Sp |
4796 | If your embedding application does not need any priorities, defining these |
4815 | If your embedding application does not need any priorities, defining these |
4797 | both to \f(CW0\fR will save some memory and \s-1CPU\s0. |
4816 | both to \f(CW0\fR will save some memory and \s-1CPU.\s0 |
4798 | .IP "\s-1EV_PERIODIC_ENABLE\s0, \s-1EV_IDLE_ENABLE\s0, \s-1EV_EMBED_ENABLE\s0, \s-1EV_STAT_ENABLE\s0, \s-1EV_PREPARE_ENABLE\s0, \s-1EV_CHECK_ENABLE\s0, \s-1EV_FORK_ENABLE\s0, \s-1EV_SIGNAL_ENABLE\s0, \s-1EV_ASYNC_ENABLE\s0, \s-1EV_CHILD_ENABLE\s0." 4 |
4817 | .IP "\s-1EV_PERIODIC_ENABLE, EV_IDLE_ENABLE, EV_EMBED_ENABLE, EV_STAT_ENABLE, EV_PREPARE_ENABLE, EV_CHECK_ENABLE, EV_FORK_ENABLE, EV_SIGNAL_ENABLE, EV_ASYNC_ENABLE, EV_CHILD_ENABLE.\s0" 4 |
4799 | .IX Item "EV_PERIODIC_ENABLE, EV_IDLE_ENABLE, EV_EMBED_ENABLE, EV_STAT_ENABLE, EV_PREPARE_ENABLE, EV_CHECK_ENABLE, EV_FORK_ENABLE, EV_SIGNAL_ENABLE, EV_ASYNC_ENABLE, EV_CHILD_ENABLE." |
4818 | .IX Item "EV_PERIODIC_ENABLE, EV_IDLE_ENABLE, EV_EMBED_ENABLE, EV_STAT_ENABLE, EV_PREPARE_ENABLE, EV_CHECK_ENABLE, EV_FORK_ENABLE, EV_SIGNAL_ENABLE, EV_ASYNC_ENABLE, EV_CHILD_ENABLE." |
4800 | If undefined or defined to be \f(CW1\fR (and the platform supports it), then |
4819 | If undefined or defined to be \f(CW1\fR (and the platform supports it), then |
4801 | the respective watcher type is supported. If defined to be \f(CW0\fR, then it |
4820 | the respective watcher type is supported. If defined to be \f(CW0\fR, then it |
4802 | is not. Disabling watcher types mainly saves code size. |
4821 | is not. Disabling watcher types mainly saves code size. |
4803 | .IP "\s-1EV_FEATURES\s0" 4 |
4822 | .IP "\s-1EV_FEATURES\s0" 4 |
… | |
… | |
4977 | .Vb 3 |
4996 | .Vb 3 |
4978 | \& #define EV_COMMON \e |
4997 | \& #define EV_COMMON \e |
4979 | \& SV *self; /* contains this struct */ \e |
4998 | \& SV *self; /* contains this struct */ \e |
4980 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
4999 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
4981 | .Ve |
5000 | .Ve |
4982 | .IP "\s-1EV_CB_DECLARE\s0 (type)" 4 |
5001 | .IP "\s-1EV_CB_DECLARE \s0(type)" 4 |
4983 | .IX Item "EV_CB_DECLARE (type)" |
5002 | .IX Item "EV_CB_DECLARE (type)" |
4984 | .PD 0 |
5003 | .PD 0 |
4985 | .IP "\s-1EV_CB_INVOKE\s0 (watcher, revents)" 4 |
5004 | .IP "\s-1EV_CB_INVOKE \s0(watcher, revents)" 4 |
4986 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
5005 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
4987 | .IP "ev_set_cb (ev, cb)" 4 |
5006 | .IP "ev_set_cb (ev, cb)" 4 |
4988 | .IX Item "ev_set_cb (ev, cb)" |
5007 | .IX Item "ev_set_cb (ev, cb)" |
4989 | .PD |
5008 | .PD |
4990 | Can be used to change the callback member declaration in each watcher, |
5009 | Can be used to change the callback member declaration in each watcher, |
4991 | and the way callbacks are invoked and set. Must expand to a struct member |
5010 | and the way callbacks are invoked and set. Must expand to a struct member |
4992 | definition and a statement, respectively. See the \fIev.h\fR header file for |
5011 | definition and a statement, respectively. See the \fIev.h\fR header file for |
4993 | their default definitions. One possible use for overriding these is to |
5012 | their default definitions. One possible use for overriding these is to |
4994 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
5013 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
4995 | method calls instead of plain function calls in \*(C+. |
5014 | method calls instead of plain function calls in \*(C+. |
4996 | .SS "\s-1EXPORTED\s0 \s-1API\s0 \s-1SYMBOLS\s0" |
5015 | .SS "\s-1EXPORTED API SYMBOLS\s0" |
4997 | .IX Subsection "EXPORTED API SYMBOLS" |
5016 | .IX Subsection "EXPORTED API SYMBOLS" |
4998 | If you need to re-export the \s-1API\s0 (e.g. via a \s-1DLL\s0) and you need a list of |
5017 | If you need to re-export the \s-1API \s0(e.g. via a \s-1DLL\s0) and you need a list of |
4999 | exported symbols, you can use the provided \fISymbol.*\fR files which list |
5018 | exported symbols, you can use the provided \fISymbol.*\fR files which list |
5000 | all public symbols, one per line: |
5019 | all public symbols, one per line: |
5001 | .PP |
5020 | .PP |
5002 | .Vb 2 |
5021 | .Vb 2 |
5003 | \& Symbols.ev for libev proper |
5022 | \& Symbols.ev for libev proper |
… | |
… | |
5055 | \& #include "ev_cpp.h" |
5074 | \& #include "ev_cpp.h" |
5056 | \& #include "ev.c" |
5075 | \& #include "ev.c" |
5057 | .Ve |
5076 | .Ve |
5058 | .SH "INTERACTION WITH OTHER PROGRAMS, LIBRARIES OR THE ENVIRONMENT" |
5077 | .SH "INTERACTION WITH OTHER PROGRAMS, LIBRARIES OR THE ENVIRONMENT" |
5059 | .IX Header "INTERACTION WITH OTHER PROGRAMS, LIBRARIES OR THE ENVIRONMENT" |
5078 | .IX Header "INTERACTION WITH OTHER PROGRAMS, LIBRARIES OR THE ENVIRONMENT" |
5060 | .SS "\s-1THREADS\s0 \s-1AND\s0 \s-1COROUTINES\s0" |
5079 | .SS "\s-1THREADS AND COROUTINES\s0" |
5061 | .IX Subsection "THREADS AND COROUTINES" |
5080 | .IX Subsection "THREADS AND COROUTINES" |
5062 | \fI\s-1THREADS\s0\fR |
5081 | \fI\s-1THREADS\s0\fR |
5063 | .IX Subsection "THREADS" |
5082 | .IX Subsection "THREADS" |
5064 | .PP |
5083 | .PP |
5065 | All libev functions are reentrant and thread-safe unless explicitly |
5084 | All libev functions are reentrant and thread-safe unless explicitly |
… | |
… | |
5111 | An example use would be to communicate signals or other events that only |
5130 | An example use would be to communicate signals or other events that only |
5112 | work in the default loop by registering the signal watcher with the |
5131 | work in the default loop by registering the signal watcher with the |
5113 | default loop and triggering an \f(CW\*(C`ev_async\*(C'\fR watcher from the default loop |
5132 | default loop and triggering an \f(CW\*(C`ev_async\*(C'\fR watcher from the default loop |
5114 | watcher callback into the event loop interested in the signal. |
5133 | watcher callback into the event loop interested in the signal. |
5115 | .PP |
5134 | .PP |
5116 | See also \*(L"\s-1THREAD\s0 \s-1LOCKING\s0 \s-1EXAMPLE\s0\*(R". |
5135 | See also \*(L"\s-1THREAD LOCKING EXAMPLE\*(R"\s0. |
5117 | .PP |
5136 | .PP |
5118 | \fI\s-1COROUTINES\s0\fR |
5137 | \fI\s-1COROUTINES\s0\fR |
5119 | .IX Subsection "COROUTINES" |
5138 | .IX Subsection "COROUTINES" |
5120 | .PP |
5139 | .PP |
5121 | Libev is very accommodating to coroutines (\*(L"cooperative threads\*(R"): |
5140 | Libev is very accommodating to coroutines (\*(L"cooperative threads\*(R"): |
… | |
… | |
5126 | that you must not do this from \f(CW\*(C`ev_periodic\*(C'\fR reschedule callbacks. |
5145 | that you must not do this from \f(CW\*(C`ev_periodic\*(C'\fR reschedule callbacks. |
5127 | .PP |
5146 | .PP |
5128 | Care has been taken to ensure that libev does not keep local state inside |
5147 | Care has been taken to ensure that libev does not keep local state inside |
5129 | \&\f(CW\*(C`ev_run\*(C'\fR, and other calls do not usually allow for coroutine switches as |
5148 | \&\f(CW\*(C`ev_run\*(C'\fR, and other calls do not usually allow for coroutine switches as |
5130 | they do not call any callbacks. |
5149 | they do not call any callbacks. |
5131 | .SS "\s-1COMPILER\s0 \s-1WARNINGS\s0" |
5150 | .SS "\s-1COMPILER WARNINGS\s0" |
5132 | .IX Subsection "COMPILER WARNINGS" |
5151 | .IX Subsection "COMPILER WARNINGS" |
5133 | Depending on your compiler and compiler settings, you might get no or a |
5152 | Depending on your compiler and compiler settings, you might get no or a |
5134 | lot of warnings when compiling libev code. Some people are apparently |
5153 | lot of warnings when compiling libev code. Some people are apparently |
5135 | scared by this. |
5154 | scared by this. |
5136 | .PP |
5155 | .PP |
… | |
… | |
5188 | .PP |
5207 | .PP |
5189 | If you need, for some reason, empty reports from valgrind for your project |
5208 | If you need, for some reason, empty reports from valgrind for your project |
5190 | I suggest using suppression lists. |
5209 | I suggest using suppression lists. |
5191 | .SH "PORTABILITY NOTES" |
5210 | .SH "PORTABILITY NOTES" |
5192 | .IX Header "PORTABILITY NOTES" |
5211 | .IX Header "PORTABILITY NOTES" |
5193 | .SS "\s-1GNU/LINUX\s0 32 \s-1BIT\s0 \s-1LIMITATIONS\s0" |
5212 | .SS "\s-1GNU/LINUX 32 BIT LIMITATIONS\s0" |
5194 | .IX Subsection "GNU/LINUX 32 BIT LIMITATIONS" |
5213 | .IX Subsection "GNU/LINUX 32 BIT LIMITATIONS" |
5195 | GNU/Linux is the only common platform that supports 64 bit file/large file |
5214 | GNU/Linux is the only common platform that supports 64 bit file/large file |
5196 | interfaces but \fIdisables\fR them by default. |
5215 | interfaces but \fIdisables\fR them by default. |
5197 | .PP |
5216 | .PP |
5198 | That means that libev compiled in the default environment doesn't support |
5217 | That means that libev compiled in the default environment doesn't support |
5199 | files larger than 2GiB or so, which mainly affects \f(CW\*(C`ev_stat\*(C'\fR watchers. |
5218 | files larger than 2GiB or so, which mainly affects \f(CW\*(C`ev_stat\*(C'\fR watchers. |
5200 | .PP |
5219 | .PP |
5201 | Unfortunately, many programs try to work around this GNU/Linux issue |
5220 | Unfortunately, many programs try to work around this GNU/Linux issue |
5202 | by enabling the large file \s-1API\s0, which makes them incompatible with the |
5221 | by enabling the large file \s-1API,\s0 which makes them incompatible with the |
5203 | standard libev compiled for their system. |
5222 | standard libev compiled for their system. |
5204 | .PP |
5223 | .PP |
5205 | Likewise, libev cannot enable the large file \s-1API\s0 itself as this would |
5224 | Likewise, libev cannot enable the large file \s-1API\s0 itself as this would |
5206 | suddenly make it incompatible to the default compile time environment, |
5225 | suddenly make it incompatible to the default compile time environment, |
5207 | i.e. all programs not using special compile switches. |
5226 | i.e. all programs not using special compile switches. |
5208 | .SS "\s-1OS/X\s0 \s-1AND\s0 \s-1DARWIN\s0 \s-1BUGS\s0" |
5227 | .SS "\s-1OS/X AND DARWIN BUGS\s0" |
5209 | .IX Subsection "OS/X AND DARWIN BUGS" |
5228 | .IX Subsection "OS/X AND DARWIN BUGS" |
5210 | The whole thing is a bug if you ask me \- basically any system interface |
5229 | The whole thing is a bug if you ask me \- basically any system interface |
5211 | you touch is broken, whether it is locales, poll, kqueue or even the |
5230 | you touch is broken, whether it is locales, poll, kqueue or even the |
5212 | OpenGL drivers. |
5231 | OpenGL drivers. |
5213 | .PP |
5232 | .PP |
… | |
… | |
5235 | .PP |
5254 | .PP |
5236 | \fI\f(CI\*(C`select\*(C'\fI is buggy\fR |
5255 | \fI\f(CI\*(C`select\*(C'\fI is buggy\fR |
5237 | .IX Subsection "select is buggy" |
5256 | .IX Subsection "select is buggy" |
5238 | .PP |
5257 | .PP |
5239 | All that's left is \f(CW\*(C`select\*(C'\fR, and of course Apple found a way to fuck this |
5258 | All that's left is \f(CW\*(C`select\*(C'\fR, and of course Apple found a way to fuck this |
5240 | one up as well: On \s-1OS/X\s0, \f(CW\*(C`select\*(C'\fR actively limits the number of file |
5259 | one up as well: On \s-1OS/X, \s0\f(CW\*(C`select\*(C'\fR actively limits the number of file |
5241 | descriptors you can pass in to 1024 \- your program suddenly crashes when |
5260 | descriptors you can pass in to 1024 \- your program suddenly crashes when |
5242 | you use more. |
5261 | you use more. |
5243 | .PP |
5262 | .PP |
5244 | There is an undocumented \*(L"workaround\*(R" for this \- defining |
5263 | There is an undocumented \*(L"workaround\*(R" for this \- defining |
5245 | \&\f(CW\*(C`_DARWIN_UNLIMITED_SELECT\*(C'\fR, which libev tries to use, so select \fIshould\fR |
5264 | \&\f(CW\*(C`_DARWIN_UNLIMITED_SELECT\*(C'\fR, which libev tries to use, so select \fIshould\fR |
5246 | work on \s-1OS/X\s0. |
5265 | work on \s-1OS/X.\s0 |
5247 | .SS "\s-1SOLARIS\s0 \s-1PROBLEMS\s0 \s-1AND\s0 \s-1WORKAROUNDS\s0" |
5266 | .SS "\s-1SOLARIS PROBLEMS AND WORKAROUNDS\s0" |
5248 | .IX Subsection "SOLARIS PROBLEMS AND WORKAROUNDS" |
5267 | .IX Subsection "SOLARIS PROBLEMS AND WORKAROUNDS" |
5249 | \fI\f(CI\*(C`errno\*(C'\fI reentrancy\fR |
5268 | \fI\f(CI\*(C`errno\*(C'\fI reentrancy\fR |
5250 | .IX Subsection "errno reentrancy" |
5269 | .IX Subsection "errno reentrancy" |
5251 | .PP |
5270 | .PP |
5252 | The default compile environment on Solaris is unfortunately so |
5271 | The default compile environment on Solaris is unfortunately so |
… | |
… | |
5269 | great. |
5288 | great. |
5270 | .PP |
5289 | .PP |
5271 | If you can't get it to work, you can try running the program by setting |
5290 | If you can't get it to work, you can try running the program by setting |
5272 | the environment variable \f(CW\*(C`LIBEV_FLAGS=3\*(C'\fR to only allow \f(CW\*(C`poll\*(C'\fR and |
5291 | the environment variable \f(CW\*(C`LIBEV_FLAGS=3\*(C'\fR to only allow \f(CW\*(C`poll\*(C'\fR and |
5273 | \&\f(CW\*(C`select\*(C'\fR backends. |
5292 | \&\f(CW\*(C`select\*(C'\fR backends. |
5274 | .SS "\s-1AIX\s0 \s-1POLL\s0 \s-1BUG\s0" |
5293 | .SS "\s-1AIX POLL BUG\s0" |
5275 | .IX Subsection "AIX POLL BUG" |
5294 | .IX Subsection "AIX POLL BUG" |
5276 | \&\s-1AIX\s0 unfortunately has a broken \f(CW\*(C`poll.h\*(C'\fR header. Libev works around |
5295 | \&\s-1AIX\s0 unfortunately has a broken \f(CW\*(C`poll.h\*(C'\fR header. Libev works around |
5277 | this by trying to avoid the poll backend altogether (i.e. it's not even |
5296 | this by trying to avoid the poll backend altogether (i.e. it's not even |
5278 | compiled in), which normally isn't a big problem as \f(CW\*(C`select\*(C'\fR works fine |
5297 | compiled in), which normally isn't a big problem as \f(CW\*(C`select\*(C'\fR works fine |
5279 | with large bitsets on \s-1AIX\s0, and \s-1AIX\s0 is dead anyway. |
5298 | with large bitsets on \s-1AIX,\s0 and \s-1AIX\s0 is dead anyway. |
5280 | .SS "\s-1WIN32\s0 \s-1PLATFORM\s0 \s-1LIMITATIONS\s0 \s-1AND\s0 \s-1WORKAROUNDS\s0" |
5299 | .SS "\s-1WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS\s0" |
5281 | .IX Subsection "WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS" |
5300 | .IX Subsection "WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS" |
5282 | \fIGeneral issues\fR |
5301 | \fIGeneral issues\fR |
5283 | .IX Subsection "General issues" |
5302 | .IX Subsection "General issues" |
5284 | .PP |
5303 | .PP |
5285 | Win32 doesn't support any of the standards (e.g. \s-1POSIX\s0) that libev |
5304 | Win32 doesn't support any of the standards (e.g. \s-1POSIX\s0) that libev |
… | |
… | |
5354 | \& #define EV_USE_SELECT 1 |
5373 | \& #define EV_USE_SELECT 1 |
5355 | \& #define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */ |
5374 | \& #define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */ |
5356 | .Ve |
5375 | .Ve |
5357 | .PP |
5376 | .PP |
5358 | Note that winsockets handling of fd sets is O(n), so you can easily get a |
5377 | Note that winsockets handling of fd sets is O(n), so you can easily get a |
5359 | complexity in the O(nA\*^X) range when using win32. |
5378 | complexity in the O(nX) range when using win32. |
5360 | .PP |
5379 | .PP |
5361 | \fILimited number of file descriptors\fR |
5380 | \fILimited number of file descriptors\fR |
5362 | .IX Subsection "Limited number of file descriptors" |
5381 | .IX Subsection "Limited number of file descriptors" |
5363 | .PP |
5382 | .PP |
5364 | Windows has numerous arbitrary (and low) limits on things. |
5383 | Windows has numerous arbitrary (and low) limits on things. |
… | |
… | |
5380 | by calling \f(CW\*(C`_setmaxstdio\*(C'\fR, which can increase this limit to \f(CW2048\fR |
5399 | by calling \f(CW\*(C`_setmaxstdio\*(C'\fR, which can increase this limit to \f(CW2048\fR |
5381 | (another arbitrary limit), but is broken in many versions of the Microsoft |
5400 | (another arbitrary limit), but is broken in many versions of the Microsoft |
5382 | runtime libraries. This might get you to about \f(CW512\fR or \f(CW2048\fR sockets |
5401 | runtime libraries. This might get you to about \f(CW512\fR or \f(CW2048\fR sockets |
5383 | (depending on windows version and/or the phase of the moon). To get more, |
5402 | (depending on windows version and/or the phase of the moon). To get more, |
5384 | you need to wrap all I/O functions and provide your own fd management, but |
5403 | you need to wrap all I/O functions and provide your own fd management, but |
5385 | the cost of calling select (O(nA\*^X)) will likely make this unworkable. |
5404 | the cost of calling select (O(nX)) will likely make this unworkable. |
5386 | .SS "\s-1PORTABILITY\s0 \s-1REQUIREMENTS\s0" |
5405 | .SS "\s-1PORTABILITY REQUIREMENTS\s0" |
5387 | .IX Subsection "PORTABILITY REQUIREMENTS" |
5406 | .IX Subsection "PORTABILITY REQUIREMENTS" |
5388 | In addition to a working ISO-C implementation and of course the |
5407 | In addition to a working ISO-C implementation and of course the |
5389 | backend-specific APIs, libev relies on a few additional extensions: |
5408 | backend-specific APIs, libev relies on a few additional extensions: |
5390 | .ie n .IP """void (*)(ev_watcher_type *, int revents)"" must have compatible calling conventions regardless of ""ev_watcher_type *""." 4 |
5409 | .ie n .IP """void (*)(ev_watcher_type *, int revents)"" must have compatible calling conventions regardless of ""ev_watcher_type *""." 4 |
5391 | .el .IP "\f(CWvoid (*)(ev_watcher_type *, int revents)\fR must have compatible calling conventions regardless of \f(CWev_watcher_type *\fR." 4 |
5410 | .el .IP "\f(CWvoid (*)(ev_watcher_type *, int revents)\fR must have compatible calling conventions regardless of \f(CWev_watcher_type *\fR." 4 |
5392 | .IX Item "void (*)(ev_watcher_type *, int revents) must have compatible calling conventions regardless of ev_watcher_type *." |
5411 | .IX Item "void (*)(ev_watcher_type *, int revents) must have compatible calling conventions regardless of ev_watcher_type *." |
5393 | Libev assumes not only that all watcher pointers have the same internal |
5412 | Libev assumes not only that all watcher pointers have the same internal |
5394 | structure (guaranteed by \s-1POSIX\s0 but not by \s-1ISO\s0 C for example), but it also |
5413 | structure (guaranteed by \s-1POSIX\s0 but not by \s-1ISO C\s0 for example), but it also |
5395 | assumes that the same (machine) code can be used to call any watcher |
5414 | assumes that the same (machine) code can be used to call any watcher |
5396 | callback: The watcher callbacks have different type signatures, but libev |
5415 | callback: The watcher callbacks have different type signatures, but libev |
5397 | calls them using an \f(CW\*(C`ev_watcher *\*(C'\fR internally. |
5416 | calls them using an \f(CW\*(C`ev_watcher *\*(C'\fR internally. |
|
|
5417 | .IP "null pointers and integer zero are represented by 0 bytes" 4 |
|
|
5418 | .IX Item "null pointers and integer zero are represented by 0 bytes" |
|
|
5419 | Libev uses \f(CW\*(C`memset\*(C'\fR to initialise structs and arrays to \f(CW0\fR bytes, and |
|
|
5420 | relies on this setting pointers and integers to null. |
5398 | .IP "pointer accesses must be thread-atomic" 4 |
5421 | .IP "pointer accesses must be thread-atomic" 4 |
5399 | .IX Item "pointer accesses must be thread-atomic" |
5422 | .IX Item "pointer accesses must be thread-atomic" |
5400 | Accessing a pointer value must be atomic, it must both be readable and |
5423 | Accessing a pointer value must be atomic, it must both be readable and |
5401 | writable in one piece \- this is the case on all current architectures. |
5424 | writable in one piece \- this is the case on all current architectures. |
5402 | .ie n .IP """sig_atomic_t volatile"" must be thread-atomic as well" 4 |
5425 | .ie n .IP """sig_atomic_t volatile"" must be thread-atomic as well" 4 |
… | |
… | |
5420 | except the initial one, and run the signal handling loop in the initial |
5443 | except the initial one, and run the signal handling loop in the initial |
5421 | thread as well. |
5444 | thread as well. |
5422 | .ie n .IP """long"" must be large enough for common memory allocation sizes" 4 |
5445 | .ie n .IP """long"" must be large enough for common memory allocation sizes" 4 |
5423 | .el .IP "\f(CWlong\fR must be large enough for common memory allocation sizes" 4 |
5446 | .el .IP "\f(CWlong\fR must be large enough for common memory allocation sizes" 4 |
5424 | .IX Item "long must be large enough for common memory allocation sizes" |
5447 | .IX Item "long must be large enough for common memory allocation sizes" |
5425 | To improve portability and simplify its \s-1API\s0, libev uses \f(CW\*(C`long\*(C'\fR internally |
5448 | To improve portability and simplify its \s-1API,\s0 libev uses \f(CW\*(C`long\*(C'\fR internally |
5426 | instead of \f(CW\*(C`size_t\*(C'\fR when allocating its data structures. On non-POSIX |
5449 | instead of \f(CW\*(C`size_t\*(C'\fR when allocating its data structures. On non-POSIX |
5427 | systems (Microsoft...) this might be unexpectedly low, but is still at |
5450 | systems (Microsoft...) this might be unexpectedly low, but is still at |
5428 | least 31 bits everywhere, which is enough for hundreds of millions of |
5451 | least 31 bits everywhere, which is enough for hundreds of millions of |
5429 | watchers. |
5452 | watchers. |
5430 | .ie n .IP """double"" must hold a time value in seconds with enough accuracy" 4 |
5453 | .ie n .IP """double"" must hold a time value in seconds with enough accuracy" 4 |
… | |
… | |
5432 | .IX Item "double must hold a time value in seconds with enough accuracy" |
5455 | .IX Item "double must hold a time value in seconds with enough accuracy" |
5433 | The type \f(CW\*(C`double\*(C'\fR is used to represent timestamps. It is required to |
5456 | The type \f(CW\*(C`double\*(C'\fR is used to represent timestamps. It is required to |
5434 | have at least 51 bits of mantissa (and 9 bits of exponent), which is |
5457 | have at least 51 bits of mantissa (and 9 bits of exponent), which is |
5435 | good enough for at least into the year 4000 with millisecond accuracy |
5458 | good enough for at least into the year 4000 with millisecond accuracy |
5436 | (the design goal for libev). This requirement is overfulfilled by |
5459 | (the design goal for libev). This requirement is overfulfilled by |
5437 | implementations using \s-1IEEE\s0 754, which is basically all existing ones. |
5460 | implementations using \s-1IEEE 754,\s0 which is basically all existing ones. |
5438 | .Sp |
5461 | .Sp |
5439 | With \s-1IEEE\s0 754 doubles, you get microsecond accuracy until at least the |
5462 | With \s-1IEEE 754\s0 doubles, you get microsecond accuracy until at least the |
5440 | year 2255 (and millisecond accuracy till the year 287396 \- by then, libev |
5463 | year 2255 (and millisecond accuracy till the year 287396 \- by then, libev |
5441 | is either obsolete or somebody patched it to use \f(CW\*(C`long double\*(C'\fR or |
5464 | is either obsolete or somebody patched it to use \f(CW\*(C`long double\*(C'\fR or |
5442 | something like that, just kidding). |
5465 | something like that, just kidding). |
5443 | .PP |
5466 | .PP |
5444 | If you know of other additional requirements drop me a note. |
5467 | If you know of other additional requirements drop me a note. |
… | |
… | |
5506 | calls in the current loop iteration and the loop is currently |
5529 | calls in the current loop iteration and the loop is currently |
5507 | blocked. Checking for async and signal events involves iterating over all |
5530 | blocked. Checking for async and signal events involves iterating over all |
5508 | running async watchers or all signal numbers. |
5531 | running async watchers or all signal numbers. |
5509 | .SH "PORTING FROM LIBEV 3.X TO 4.X" |
5532 | .SH "PORTING FROM LIBEV 3.X TO 4.X" |
5510 | .IX Header "PORTING FROM LIBEV 3.X TO 4.X" |
5533 | .IX Header "PORTING FROM LIBEV 3.X TO 4.X" |
5511 | The major version 4 introduced some incompatible changes to the \s-1API\s0. |
5534 | The major version 4 introduced some incompatible changes to the \s-1API.\s0 |
5512 | .PP |
5535 | .PP |
5513 | At the moment, the \f(CW\*(C`ev.h\*(C'\fR header file provides compatibility definitions |
5536 | At the moment, the \f(CW\*(C`ev.h\*(C'\fR header file provides compatibility definitions |
5514 | for all changes, so most programs should still compile. The compatibility |
5537 | for all changes, so most programs should still compile. The compatibility |
5515 | layer might be removed in later versions of libev, so better update to the |
5538 | layer might be removed in later versions of libev, so better update to the |
5516 | new \s-1API\s0 early than late. |
5539 | new \s-1API\s0 early than late. |
5517 | .ie n .IP """EV_COMPAT3"" backwards compatibility mechanism" 4 |
5540 | .ie n .IP """EV_COMPAT3"" backwards compatibility mechanism" 4 |
5518 | .el .IP "\f(CWEV_COMPAT3\fR backwards compatibility mechanism" 4 |
5541 | .el .IP "\f(CWEV_COMPAT3\fR backwards compatibility mechanism" 4 |
5519 | .IX Item "EV_COMPAT3 backwards compatibility mechanism" |
5542 | .IX Item "EV_COMPAT3 backwards compatibility mechanism" |
5520 | The backward compatibility mechanism can be controlled by |
5543 | The backward compatibility mechanism can be controlled by |
5521 | \&\f(CW\*(C`EV_COMPAT3\*(C'\fR. See \*(L"\s-1PREPROCESSOR\s0 \s-1SYMBOLS/MACROS\s0\*(R" in the \*(L"\s-1EMBEDDING\s0\*(R" |
5544 | \&\f(CW\*(C`EV_COMPAT3\*(C'\fR. See \*(L"\s-1PREPROCESSOR SYMBOLS/MACROS\*(R"\s0 in the \*(L"\s-1EMBEDDING\*(R"\s0 |
5522 | section. |
5545 | section. |
5523 | .ie n .IP """ev_default_destroy"" and ""ev_default_fork"" have been removed" 4 |
5546 | .ie n .IP """ev_default_destroy"" and ""ev_default_fork"" have been removed" 4 |
5524 | .el .IP "\f(CWev_default_destroy\fR and \f(CWev_default_fork\fR have been removed" 4 |
5547 | .el .IP "\f(CWev_default_destroy\fR and \f(CWev_default_fork\fR have been removed" 4 |
5525 | .IX Item "ev_default_destroy and ev_default_fork have been removed" |
5548 | .IX Item "ev_default_destroy and ev_default_fork have been removed" |
5526 | These calls can be replaced easily by their \f(CW\*(C`ev_loop_xxx\*(C'\fR counterparts: |
5549 | These calls can be replaced easily by their \f(CW\*(C`ev_loop_xxx\*(C'\fR counterparts: |
… | |
… | |
5566 | .SH "GLOSSARY" |
5589 | .SH "GLOSSARY" |
5567 | .IX Header "GLOSSARY" |
5590 | .IX Header "GLOSSARY" |
5568 | .IP "active" 4 |
5591 | .IP "active" 4 |
5569 | .IX Item "active" |
5592 | .IX Item "active" |
5570 | A watcher is active as long as it has been started and not yet stopped. |
5593 | A watcher is active as long as it has been started and not yet stopped. |
5571 | See \*(L"\s-1WATCHER\s0 \s-1STATES\s0\*(R" for details. |
5594 | See \*(L"\s-1WATCHER STATES\*(R"\s0 for details. |
5572 | .IP "application" 4 |
5595 | .IP "application" 4 |
5573 | .IX Item "application" |
5596 | .IX Item "application" |
5574 | In this document, an application is whatever is using libev. |
5597 | In this document, an application is whatever is using libev. |
5575 | .IP "backend" 4 |
5598 | .IP "backend" 4 |
5576 | .IX Item "backend" |
5599 | .IX Item "backend" |
… | |
… | |
5603 | The model used to describe how an event loop handles and processes |
5626 | The model used to describe how an event loop handles and processes |
5604 | watchers and events. |
5627 | watchers and events. |
5605 | .IP "pending" 4 |
5628 | .IP "pending" 4 |
5606 | .IX Item "pending" |
5629 | .IX Item "pending" |
5607 | A watcher is pending as soon as the corresponding event has been |
5630 | A watcher is pending as soon as the corresponding event has been |
5608 | detected. See \*(L"\s-1WATCHER\s0 \s-1STATES\s0\*(R" for details. |
5631 | detected. See \*(L"\s-1WATCHER STATES\*(R"\s0 for details. |
5609 | .IP "real time" 4 |
5632 | .IP "real time" 4 |
5610 | .IX Item "real time" |
5633 | .IX Item "real time" |
5611 | The physical time that is observed. It is apparently strictly monotonic :) |
5634 | The physical time that is observed. It is apparently strictly monotonic :) |
5612 | .IP "wall-clock time" 4 |
5635 | .IP "wall-clock time" 4 |
5613 | .IX Item "wall-clock time" |
5636 | .IX Item "wall-clock time" |