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126 | .IX Title "LIBEV 3" |
135 | .IX Title "LIBEV 3" |
127 | .TH LIBEV 3 "2013-02-18" "libev-4.11" "libev - high performance full featured event loop" |
136 | .TH LIBEV 3 "2018-12-21" "libev-4.25" "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 |
… | |
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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. |
526 | .Sp |
537 | .Sp |
527 | This works by calling \f(CW\*(C`getpid ()\*(C'\fR on every iteration of the loop, |
538 | This works by calling \f(CW\*(C`getpid ()\*(C'\fR on every iteration of the loop, |
528 | and thus this might slow down your event loop if you do a lot of loop |
539 | and thus this might slow down your event loop if you do a lot of loop |
529 | iterations and little real work, but is usually not noticeable (on my |
540 | iterations and little real work, but is usually not noticeable (on my |
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 |
531 | without a system call and thus \fIvery\fR fast, but my GNU/Linux system also has |
542 | sequence without a system call and thus \fIvery\fR fast, but my GNU/Linux |
532 | \&\f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). |
543 | system also has \f(CW\*(C`pthread_atfork\*(C'\fR which is even faster). (Update: glibc |
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|
544 | versions 2.25 apparently removed the \f(CW\*(C`getpid\*(C'\fR optimisation again). |
533 | .Sp |
545 | .Sp |
534 | The big advantage of this flag is that you can forget about fork (and |
546 | 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 |
547 | forget about forgetting to tell libev about forking, although you still |
536 | flag. |
548 | have to ignore \f(CW\*(C`SIGPIPE\*(C'\fR) when you use this flag. |
537 | .Sp |
549 | .Sp |
538 | This flag setting cannot be overridden or specified in the \f(CW\*(C`LIBEV_FLAGS\*(C'\fR |
550 | This flag setting cannot be overridden or specified in the \f(CW\*(C`LIBEV_FLAGS\*(C'\fR |
539 | environment variable. |
551 | environment variable. |
540 | .ie n .IP """EVFLAG_NOINOTIFY""" 4 |
552 | .ie n .IP """EVFLAG_NOINOTIFY""" 4 |
541 | .el .IP "\f(CWEVFLAG_NOINOTIFY\fR" 4 |
553 | .el .IP "\f(CWEVFLAG_NOINOTIFY\fR" 4 |
… | |
… | |
572 | \&\f(CW\*(C`sigprocmask\*(C'\fR, whose behaviour is officially unspecified. |
584 | \&\f(CW\*(C`sigprocmask\*(C'\fR, whose behaviour is officially unspecified. |
573 | .Sp |
585 | .Sp |
574 | This flag's behaviour will become the default in future versions of libev. |
586 | 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 |
587 | .ie n .IP """EVBACKEND_SELECT"" (value 1, portable select backend)" 4 |
576 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
588 | .el .IP "\f(CWEVBACKEND_SELECT\fR (value 1, portable select backend)" 4 |
577 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
589 | .IX Item "EVBACKEND_SELECT (value 1, portable select backend)" |
578 | This is your standard \fIselect\fR\|(2) backend. Not \fIcompletely\fR standard, as |
590 | 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, |
591 | 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 |
592 | 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 |
593 | 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. |
594 | usually the fastest backend for a low number of (low-numbered :) fds. |
… | |
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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 |
603 | 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 |
604 | \&\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). |
605 | \&\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 |
606 | .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 |
607 | .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)" |
608 | .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 |
609 | 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 |
610 | 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 |
611 | 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, |
612 | 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 |
613 | i.e. O(total_fds). See the entry for \f(CW\*(C`EVBACKEND_SELECT\*(C'\fR, above, for |
… | |
… | |
603 | .Sp |
615 | .Sp |
604 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR to \f(CW\*(C`POLLIN | POLLERR | POLLHUP\*(C'\fR, and |
616 | 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. |
617 | \&\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 |
618 | .ie n .IP """EVBACKEND_EPOLL"" (value 4, Linux)" 4 |
607 | .el .IP "\f(CWEVBACKEND_EPOLL\fR (value 4, Linux)" 4 |
619 | .el .IP "\f(CWEVBACKEND_EPOLL\fR (value 4, Linux)" 4 |
608 | .IX Item "EVBACKEND_EPOLL (value 4, Linux)" |
620 | .IX Item "EVBACKEND_EPOLL (value 4, Linux)" |
609 | Use the linux-specific \fIepoll\fR\|(7) interface (for both pre\- and post\-2.6.9 |
621 | Use the linux-specific \fIepoll\fR\|(7) interface (for both pre\- and post\-2.6.9 |
610 | kernels). |
622 | kernels). |
611 | .Sp |
623 | .Sp |
612 | For few fds, this backend is a bit little slower than poll and select, but |
624 | 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 |
625 | it scales phenomenally better. While poll and select usually scale like |
… | |
… | |
666 | .Sp |
678 | .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 |
679 | 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. |
680 | \&\f(CW\*(C`EVBACKEND_POLL\*(C'\fR. |
669 | .ie n .IP """EVBACKEND_KQUEUE"" (value 8, most \s-1BSD\s0 clones)" 4 |
681 | .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 |
682 | .el .IP "\f(CWEVBACKEND_KQUEUE\fR (value 8, most \s-1BSD\s0 clones)" 4 |
671 | .IX Item "EVBACKEND_KQUEUE (value 8, most BSD clones)" |
683 | .IX Item "EVBACKEND_KQUEUE (value 8, most BSD clones)" |
672 | Kqueue deserves special mention, as at the time of this writing, it |
684 | 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 |
685 | 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 |
686 | with anything but sockets and pipes, except on Darwin, where of course |
675 | it's completely useless). Unlike epoll, however, whose brokenness |
687 | it's completely useless). Unlike epoll, however, whose brokenness |
676 | is by design, these kqueue bugs can (and eventually will) be fixed |
688 | is by design, these kqueue bugs can (and eventually will) be fixed |
… | |
… | |
696 | While nominally embeddable in other event loops, this doesn't work |
708 | 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 |
709 | 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 |
710 | 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 |
711 | (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 |
712 | (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. |
713 | also broken on \s-1OS X\s0)) and, did I mention it, using it only for sockets. |
702 | .Sp |
714 | .Sp |
703 | This backend maps \f(CW\*(C`EV_READ\*(C'\fR into an \f(CW\*(C`EVFILT_READ\*(C'\fR kevent with |
715 | 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 |
716 | \&\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. |
717 | \&\f(CW\*(C`NOTE_EOF\*(C'\fR. |
706 | .ie n .IP """EVBACKEND_DEVPOLL"" (value 16, Solaris 8)" 4 |
718 | .ie n .IP """EVBACKEND_DEVPOLL"" (value 16, Solaris 8)" 4 |
… | |
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710 | implementation). According to reports, \f(CW\*(C`/dev/poll\*(C'\fR only supports sockets |
722 | 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 |
723 | and is not embeddable, which would limit the usefulness of this backend |
712 | immensely. |
724 | immensely. |
713 | .ie n .IP """EVBACKEND_PORT"" (value 32, Solaris 10)" 4 |
725 | .ie n .IP """EVBACKEND_PORT"" (value 32, Solaris 10)" 4 |
714 | .el .IP "\f(CWEVBACKEND_PORT\fR (value 32, Solaris 10)" 4 |
726 | .el .IP "\f(CWEVBACKEND_PORT\fR (value 32, Solaris 10)" 4 |
715 | .IX Item "EVBACKEND_PORT (value 32, Solaris 10)" |
727 | .IX Item "EVBACKEND_PORT (value 32, Solaris 10)" |
716 | This uses the Solaris 10 event port mechanism. As with everything on Solaris, |
728 | 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)). |
729 | it's really slow, but it still scales very well (O(active_fds)). |
718 | .Sp |
730 | .Sp |
719 | While this backend scales well, it requires one system call per active |
731 | 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 |
732 | 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. |
811 | 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 |
812 | 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. |
813 | and \f(CW\*(C`ev_loop_destroy\*(C'\fR. |
802 | .IP "ev_loop_fork (loop)" 4 |
814 | .IP "ev_loop_fork (loop)" 4 |
803 | .IX Item "ev_loop_fork (loop)" |
815 | .IX Item "ev_loop_fork (loop)" |
804 | This function sets a flag that causes subsequent \f(CW\*(C`ev_run\*(C'\fR iterations to |
816 | 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 |
817 | 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 |
818 | 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 |
819 | 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. |
820 | sense after forking, in the child process. You \fImust\fR call it (or use |
|
|
821 | \&\f(CW\*(C`EVFLAG_FORKCHECK\*(C'\fR) in the child before resuming or calling \f(CW\*(C`ev_run\*(C'\fR. |
809 | .Sp |
822 | .Sp |
|
|
823 | In addition, if you want to reuse a loop (via this function or |
|
|
824 | \&\f(CW\*(C`EVFLAG_FORKCHECK\*(C'\fR), you \fIalso\fR have to ignore \f(CW\*(C`SIGPIPE\*(C'\fR. |
|
|
825 | .Sp |
810 | Again, you \fIhave\fR to call it on \fIany\fR loop that you want to re-use after |
826 | 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 |
827 | 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 |
828 | because some kernel interfaces *cough* \fIkqueue\fR *cough* do funny things |
813 | during fork. |
829 | during fork. |
814 | .Sp |
830 | .Sp |
815 | On the other hand, you only need to call this function in the child |
831 | 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 |
1368 | 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 |
1369 | 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 |
1370 | 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 |
1371 | programs, though, as the fd could already be closed and reused for another |
1356 | thing, so beware. |
1372 | thing, so beware. |
1357 | .SS "\s-1GENERIC\s0 \s-1WATCHER\s0 \s-1FUNCTIONS\s0" |
1373 | .SS "\s-1GENERIC WATCHER FUNCTIONS\s0" |
1358 | .IX Subsection "GENERIC WATCHER FUNCTIONS" |
1374 | .IX Subsection "GENERIC WATCHER FUNCTIONS" |
1359 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
1375 | .ie n .IP """ev_init"" (ev_TYPE *watcher, callback)" 4 |
1360 | .el .IP "\f(CWev_init\fR (ev_TYPE *watcher, callback)" 4 |
1376 | .el .IP "\f(CWev_init\fR (ev_TYPE *watcher, callback)" 4 |
1361 | .IX Item "ev_init (ev_TYPE *watcher, callback)" |
1377 | .IX Item "ev_init (ev_TYPE *watcher, callback)" |
1362 | This macro initialises the generic portion of a watcher. The contents |
1378 | This macro initialises the generic portion of a watcher. The contents |
… | |
… | |
1470 | or might not have been clamped to the valid range. |
1486 | or might not have been clamped to the valid range. |
1471 | .Sp |
1487 | .Sp |
1472 | The default priority used by watchers when no priority has been set is |
1488 | 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 :). |
1489 | always \f(CW0\fR, which is supposed to not be too high and not be too low :). |
1474 | .Sp |
1490 | .Sp |
1475 | See \*(L"\s-1WATCHER\s0 \s-1PRIORITY\s0 \s-1MODELS\s0\*(R", below, for a more thorough treatment of |
1491 | See \*(L"\s-1WATCHER PRIORITY MODELS\*(R"\s0, below, for a more thorough treatment of |
1476 | priorities. |
1492 | priorities. |
1477 | .IP "ev_invoke (loop, ev_TYPE *watcher, int revents)" 4 |
1493 | .IP "ev_invoke (loop, ev_TYPE *watcher, int revents)" 4 |
1478 | .IX Item "ev_invoke (loop, ev_TYPE *watcher, int revents)" |
1494 | .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 |
1495 | 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 |
1496 | \&\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. |
1516 | not started in the first place. |
1501 | .Sp |
1517 | .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 |
1518 | 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. |
1519 | functions that do not need a watcher. |
1504 | .PP |
1520 | .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 |
1521 | 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. |
1522 | OWN COMPOSITE WATCHERS\*(R"\s0 idioms. |
1507 | .SS "\s-1WATCHER\s0 \s-1STATES\s0" |
1523 | .SS "\s-1WATCHER STATES\s0" |
1508 | .IX Subsection "WATCHER STATES" |
1524 | .IX Subsection "WATCHER STATES" |
1509 | There are various watcher states mentioned throughout this manual \- |
1525 | There are various watcher states mentioned throughout this manual \- |
1510 | active, pending and so on. In this section these states and the rules to |
1526 | 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 |
1527 | 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". |
1528 | rules might look complicated, they usually do \*(L"the right thing\*(R". |
… | |
… | |
1555 | .Sp |
1571 | .Sp |
1556 | While stopped (and not pending) the watcher is essentially in the |
1572 | 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 |
1573 | 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 |
1574 | you wish (but when you trash the memory block, you need to \f(CW\*(C`ev_TYPE_init\*(C'\fR |
1559 | it again). |
1575 | it again). |
1560 | .SS "\s-1WATCHER\s0 \s-1PRIORITY\s0 \s-1MODELS\s0" |
1576 | .SS "\s-1WATCHER PRIORITY MODELS\s0" |
1561 | .IX Subsection "WATCHER PRIORITY MODELS" |
1577 | .IX Subsection "WATCHER PRIORITY MODELS" |
1562 | Many event loops support \fIwatcher priorities\fR, which are usually small |
1578 | Many event loops support \fIwatcher priorities\fR, which are usually small |
1563 | integers that influence the ordering of event callback invocation |
1579 | integers that influence the ordering of event callback invocation |
1564 | between watchers in some way, all else being equal. |
1580 | between watchers in some way, all else being equal. |
1565 | .PP |
1581 | .PP |
… | |
… | |
1763 | wish to read \- you would first have to request some data. |
1779 | wish to read \- you would first have to request some data. |
1764 | .PP |
1780 | .PP |
1765 | Since files are typically not-so-well supported by advanced notification |
1781 | Since files are typically not-so-well supported by advanced notification |
1766 | mechanism, libev tries hard to emulate \s-1POSIX\s0 behaviour with respect |
1782 | 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 |
1783 | 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 |
1784 | 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 |
1785 | 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 |
1786 | (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 |
1787 | \&\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 |
1788 | asynchronous I/O instead of with non-blocking I/O, it is still useful when |
1773 | it \*(L"just works\*(R" instead of freezing. |
1789 | it \*(L"just works\*(R" instead of freezing. |
1774 | .PP |
1790 | .PP |
1775 | So avoid file descriptors pointing to files when you know it (e.g. use |
1791 | 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 |
1792 | 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 |
1793 | when you rarely read from a file instead of from a socket, and want to |
1778 | reuse the same code path. |
1794 | reuse the same code path. |
1779 | .PP |
1795 | .PP |
1780 | \fIThe special problem of fork\fR |
1796 | \fIThe special problem of fork\fR |
1781 | .IX Subsection "The special problem of fork" |
1797 | .IX Subsection "The special problem of fork" |
… | |
… | |
1791 | \fIThe special problem of \s-1SIGPIPE\s0\fR |
1807 | \fIThe special problem of \s-1SIGPIPE\s0\fR |
1792 | .IX Subsection "The special problem of SIGPIPE" |
1808 | .IX Subsection "The special problem of SIGPIPE" |
1793 | .PP |
1809 | .PP |
1794 | While not really specific to libev, it is easy to forget about \f(CW\*(C`SIGPIPE\*(C'\fR: |
1810 | 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 |
1811 | 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 |
1812 | 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. |
1813 | this is sensible behaviour, for daemons, this is usually undesirable. |
1798 | .PP |
1814 | .PP |
1799 | So when you encounter spurious, unexplained daemon exits, make sure you |
1815 | 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 |
1816 | 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). |
1817 | somewhere, as that would have given you a big clue). |
1802 | .PP |
1818 | .PP |
1803 | \fIThe special problem of \fIaccept()\fIing when you can't\fR |
1819 | \fIThe special problem of \fIaccept()\fIing when you can't\fR |
1804 | .IX Subsection "The special problem of accept()ing when you can't" |
1820 | .IX Subsection "The special problem of accept()ing when you can't" |
1805 | .PP |
1821 | .PP |
1806 | Many implementations of the \s-1POSIX\s0 \f(CW\*(C`accept\*(C'\fR function (for example, |
1822 | 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 |
1823 | found in post\-2004 Linux) have the peculiar behaviour of not removing a |
1808 | connection from the pending queue in all error cases. |
1824 | connection from the pending queue in all error cases. |
1809 | .PP |
1825 | .PP |
1810 | For example, larger servers often run out of file descriptors (because |
1826 | 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 |
1827 | of resource limits), causing \f(CW\*(C`accept\*(C'\fR to fail with \f(CW\*(C`ENFILE\*(C'\fR but not |
… | |
… | |
2150 | .PP |
2166 | .PP |
2151 | The relative timeouts are calculated relative to the \f(CW\*(C`ev_now ()\*(C'\fR |
2167 | 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 |
2168 | 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 |
2169 | 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 |
2170 | 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: |
2171 | timeout on the current time, use something like the following to adjust |
|
|
2172 | for it: |
2156 | .PP |
2173 | .PP |
2157 | .Vb 1 |
2174 | .Vb 1 |
2158 | \& ev_timer_set (&timer, after + ev_now () \- ev_time (), 0.); |
2175 | \& ev_timer_set (&timer, after + (ev_time () \- ev_now ()), 0.); |
2159 | .Ve |
2176 | .Ve |
2160 | .PP |
2177 | .PP |
2161 | If the event loop is suspended for a long time, you can also force an |
2178 | 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 |
2179 | update of the time returned by \f(CW\*(C`ev_now ()\*(C'\fR by calling \f(CW\*(C`ev_now_update |
2163 | ()\*(C'\fR. |
2180 | ()\*(C'\fR, although that will push the event time of all outstanding events |
|
|
2181 | further into the future. |
2164 | .PP |
2182 | .PP |
2165 | \fIThe special problem of unsynchronised clocks\fR |
2183 | \fIThe special problem of unsynchronised clocks\fR |
2166 | .IX Subsection "The special problem of unsynchronised clocks" |
2184 | .IX Subsection "The special problem of unsynchronised clocks" |
2167 | .PP |
2185 | .PP |
2168 | Modern systems have a variety of clocks \- libev itself uses the normal |
2186 | Modern systems have a variety of clocks \- libev itself uses the normal |
… | |
… | |
2233 | .IX Item "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)" |
2251 | .IX Item "ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat)" |
2234 | .PD 0 |
2252 | .PD 0 |
2235 | .IP "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" 4 |
2253 | .IP "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" 4 |
2236 | .IX Item "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" |
2254 | .IX Item "ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat)" |
2237 | .PD |
2255 | .PD |
2238 | Configure the timer to trigger after \f(CW\*(C`after\*(C'\fR seconds. If \f(CW\*(C`repeat\*(C'\fR |
2256 | Configure the timer to trigger after \f(CW\*(C`after\*(C'\fR seconds (fractional and |
2239 | is \f(CW0.\fR, then it will automatically be stopped once the timeout is |
2257 | negative values are supported). If \f(CW\*(C`repeat\*(C'\fR is \f(CW0.\fR, then it will |
2240 | reached. If it is positive, then the timer will automatically be |
2258 | automatically be stopped once the timeout is reached. If it is positive, |
2241 | configured to trigger again \f(CW\*(C`repeat\*(C'\fR seconds later, again, and again, |
2259 | then the timer will automatically be configured to trigger again \f(CW\*(C`repeat\*(C'\fR |
2242 | until stopped manually. |
2260 | seconds later, again, and again, until stopped manually. |
2243 | .Sp |
2261 | .Sp |
2244 | The timer itself will do a best-effort at avoiding drift, that is, if |
2262 | The timer itself will do a best-effort at avoiding drift, that is, if |
2245 | you configure a timer to trigger every 10 seconds, then it will normally |
2263 | you configure a timer to trigger every 10 seconds, then it will normally |
2246 | trigger at exactly 10 second intervals. If, however, your program cannot |
2264 | trigger at exactly 10 second intervals. If, however, your program cannot |
2247 | keep up with the timer (because it takes longer than those 10 seconds to |
2265 | keep up with the timer (because it takes longer than those 10 seconds to |
… | |
… | |
2329 | Periodic watchers are also timers of a kind, but they are very versatile |
2347 | Periodic watchers are also timers of a kind, but they are very versatile |
2330 | (and unfortunately a bit complex). |
2348 | (and unfortunately a bit complex). |
2331 | .PP |
2349 | .PP |
2332 | Unlike \f(CW\*(C`ev_timer\*(C'\fR, periodic watchers are not based on real time (or |
2350 | 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 |
2351 | 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 |
2352 | (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 |
2353 | 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 |
2354 | time, and time jumps are not uncommon (e.g. when you adjust your |
2337 | wrist-watch). |
2355 | wrist-watch). |
2338 | .PP |
2356 | .PP |
2339 | You can tell a periodic watcher to trigger after some specific point |
2357 | You can tell a periodic watcher to trigger after some specific point |
… | |
… | |
2344 | \&\f(CW\*(C`ev_timer\*(C'\fR, which would still trigger roughly 10 seconds after starting |
2362 | \&\f(CW\*(C`ev_timer\*(C'\fR, which would still trigger roughly 10 seconds after starting |
2345 | it, as it uses a relative timeout). |
2363 | it, as it uses a relative timeout). |
2346 | .PP |
2364 | .PP |
2347 | \&\f(CW\*(C`ev_periodic\*(C'\fR watchers can also be used to implement vastly more complex |
2365 | \&\f(CW\*(C`ev_periodic\*(C'\fR watchers can also be used to implement vastly more complex |
2348 | timers, such as triggering an event on each \*(L"midnight, local time\*(R", or |
2366 | timers, such as triggering an event on each \*(L"midnight, local time\*(R", or |
2349 | other complicated rules. This cannot be done with \f(CW\*(C`ev_timer\*(C'\fR watchers, as |
2367 | other complicated rules. This cannot easily be done with \f(CW\*(C`ev_timer\*(C'\fR |
2350 | those cannot react to time jumps. |
2368 | watchers, as those cannot react to time jumps. |
2351 | .PP |
2369 | .PP |
2352 | As with timers, the callback is guaranteed to be invoked only when the |
2370 | As with timers, the callback is guaranteed to be invoked only when the |
2353 | point in time where it is supposed to trigger has passed. If multiple |
2371 | point in time where it is supposed to trigger has passed. If multiple |
2354 | timers become ready during the same loop iteration then the ones with |
2372 | timers become ready during the same loop iteration then the ones with |
2355 | earlier time-out values are invoked before ones with later time-out values |
2373 | earlier time-out values are invoked before ones with later time-out values |
… | |
… | |
2416 | In this mode the values for \f(CW\*(C`interval\*(C'\fR and \f(CW\*(C`offset\*(C'\fR are both being |
2434 | 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 |
2435 | ignored. Instead, each time the periodic watcher gets scheduled, the |
2418 | reschedule callback will be called with the watcher as first, and the |
2436 | reschedule callback will be called with the watcher as first, and the |
2419 | current time as second argument. |
2437 | current time as second argument. |
2420 | .Sp |
2438 | .Sp |
2421 | \&\s-1NOTE:\s0 \fIThis callback \s-1MUST\s0 \s-1NOT\s0 stop or destroy any periodic watcher, ever, |
2439 | \&\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 |
2440 | or make \s-1ANY\s0 other event loop modifications whatsoever, unless explicitly |
2423 | allowed by documentation here\fR. |
2441 | allowed by documentation here\fR. |
2424 | .Sp |
2442 | .Sp |
2425 | If you need to stop it, return \f(CW\*(C`now + 1e30\*(C'\fR (or so, fudge fudge) and stop |
2443 | 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 |
2444 | 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 |
2458 | 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 |
2459 | (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 |
2460 | will usually be called just before the callback will be triggered, but |
2443 | might be called at other times, too. |
2461 | might be called at other times, too. |
2444 | .Sp |
2462 | .Sp |
2445 | \&\s-1NOTE:\s0 \fIThis callback must always return a time that is higher than or |
2463 | \&\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. |
2464 | equal to the passed \f(CI\*(C`now\*(C'\fI value\fR. |
2447 | .Sp |
2465 | .Sp |
2448 | This can be used to create very complex timers, such as a timer that |
2466 | 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 |
2467 | triggers on \*(L"next midnight, local time\*(R". To do this, you would calculate |
2450 | next midnight after \f(CW\*(C`now\*(C'\fR and return the timestamp value for this. How |
2468 | the next midnight after \f(CW\*(C`now\*(C'\fR and return the timestamp value for |
2451 | you do this is, again, up to you (but it is not trivial, which is the main |
2469 | this. Here is a (completely untested, no error checking) example on how to |
2452 | reason I omitted it as an example). |
2470 | do this: |
|
|
2471 | .Sp |
|
|
2472 | .Vb 1 |
|
|
2473 | \& #include <time.h> |
|
|
2474 | \& |
|
|
2475 | \& static ev_tstamp |
|
|
2476 | \& my_rescheduler (ev_periodic *w, ev_tstamp now) |
|
|
2477 | \& { |
|
|
2478 | \& time_t tnow = (time_t)now; |
|
|
2479 | \& struct tm tm; |
|
|
2480 | \& localtime_r (&tnow, &tm); |
|
|
2481 | \& |
|
|
2482 | \& tm.tm_sec = tm.tm_min = tm.tm_hour = 0; // midnight current day |
|
|
2483 | \& ++tm.tm_mday; // midnight next day |
|
|
2484 | \& |
|
|
2485 | \& return mktime (&tm); |
|
|
2486 | \& } |
|
|
2487 | .Ve |
|
|
2488 | .Sp |
|
|
2489 | Note: this code might run into trouble on days that have more then two |
|
|
2490 | midnights (beginning and end). |
2453 | .RE |
2491 | .RE |
2454 | .RS 4 |
2492 | .RS 4 |
2455 | .RE |
2493 | .RE |
2456 | .IP "ev_periodic_again (loop, ev_periodic *)" 4 |
2494 | .IP "ev_periodic_again (loop, ev_periodic *)" 4 |
2457 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
2495 | .IX Item "ev_periodic_again (loop, ev_periodic *)" |
… | |
… | |
2542 | only within the same loop, i.e. you can watch for \f(CW\*(C`SIGINT\*(C'\fR in your |
2580 | 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 |
2581 | 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 |
2582 | \&\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. |
2583 | the moment, \f(CW\*(C`SIGCHLD\*(C'\fR is permanently tied to the default loop. |
2546 | .PP |
2584 | .PP |
2547 | When the first watcher gets started will libev actually register something |
2585 | 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 |
2586 | register something with the kernel. It thus coexists with your own signal |
2549 | you don't register any with libev for the same signal). |
2587 | handlers as long as you don't register any with libev for the same signal. |
2550 | .PP |
2588 | .PP |
2551 | If possible and supported, libev will install its handlers with |
2589 | 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 |
2590 | \&\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 |
2591 | 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 |
2592 | 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 |
2613 | 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 |
2614 | 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. |
2615 | catch fork calls done by libraries (such as the libc) as well. |
2578 | .PP |
2616 | .PP |
2579 | In current versions of libev, the signal will not be blocked indefinitely |
2617 | 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 |
2618 | 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 |
2619 | the window of opportunity for problems, it will not go away, as libev |
2582 | \&\fIhas\fR to modify the signal mask, at least temporarily. |
2620 | \&\fIhas\fR to modify the signal mask, at least temporarily. |
2583 | .PP |
2621 | .PP |
2584 | So I can't stress this enough: \fIIf you do not reset your signal mask when |
2622 | 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 |
2623 | you expect it to be empty, you have a race condition in your code\fR. This |
… | |
… | |
2615 | The signal the watcher watches out for. |
2653 | The signal the watcher watches out for. |
2616 | .PP |
2654 | .PP |
2617 | \fIExamples\fR |
2655 | \fIExamples\fR |
2618 | .IX Subsection "Examples" |
2656 | .IX Subsection "Examples" |
2619 | .PP |
2657 | .PP |
2620 | Example: Try to exit cleanly on \s-1SIGINT\s0. |
2658 | Example: Try to exit cleanly on \s-1SIGINT.\s0 |
2621 | .PP |
2659 | .PP |
2622 | .Vb 5 |
2660 | .Vb 5 |
2623 | \& static void |
2661 | \& static void |
2624 | \& sigint_cb (struct ev_loop *loop, ev_signal *w, int revents) |
2662 | \& sigint_cb (struct ev_loop *loop, ev_signal *w, int revents) |
2625 | \& { |
2663 | \& { |
… | |
… | |
2782 | compilation environment, which means that on systems with large file |
2820 | compilation environment, which means that on systems with large file |
2783 | support disabled by default, you get the 32 bit version of the stat |
2821 | support disabled by default, you get the 32 bit version of the stat |
2784 | structure. When using the library from programs that change the \s-1ABI\s0 to |
2822 | structure. When using the library from programs that change the \s-1ABI\s0 to |
2785 | use 64 bit file offsets the programs will fail. In that case you have to |
2823 | use 64 bit file offsets the programs will fail. In that case you have to |
2786 | compile libev with the same flags to get binary compatibility. This is |
2824 | compile libev with the same flags to get binary compatibility. This is |
2787 | obviously the case with any flags that change the \s-1ABI\s0, but the problem is |
2825 | obviously the case with any flags that change the \s-1ABI,\s0 but the problem is |
2788 | most noticeably displayed with ev_stat and large file support. |
2826 | most noticeably displayed with ev_stat and large file support. |
2789 | .PP |
2827 | .PP |
2790 | The solution for this is to lobby your distribution maker to make large |
2828 | The solution for this is to lobby your distribution maker to make large |
2791 | file interfaces available by default (as e.g. FreeBSD does) and not |
2829 | file interfaces available by default (as e.g. FreeBSD does) and not |
2792 | optional. Libev cannot simply switch on large file support because it has |
2830 | optional. Libev cannot simply switch on large file support because it has |
… | |
… | |
3037 | .IX Subsection "ev_prepare and ev_check - customise your event loop!" |
3075 | .IX Subsection "ev_prepare and ev_check - customise your event loop!" |
3038 | Prepare and check watchers are often (but not always) used in pairs: |
3076 | Prepare and check watchers are often (but not always) used in pairs: |
3039 | prepare watchers get invoked before the process blocks and check watchers |
3077 | prepare watchers get invoked before the process blocks and check watchers |
3040 | afterwards. |
3078 | afterwards. |
3041 | .PP |
3079 | .PP |
3042 | You \fImust not\fR call \f(CW\*(C`ev_run\*(C'\fR or similar functions that enter |
3080 | You \fImust not\fR call \f(CW\*(C`ev_run\*(C'\fR (or similar functions that enter the |
3043 | the current event loop from either \f(CW\*(C`ev_prepare\*(C'\fR or \f(CW\*(C`ev_check\*(C'\fR |
3081 | current event loop) or \f(CW\*(C`ev_loop_fork\*(C'\fR from either \f(CW\*(C`ev_prepare\*(C'\fR or |
3044 | watchers. Other loops than the current one are fine, however. The |
3082 | \&\f(CW\*(C`ev_check\*(C'\fR watchers. Other loops than the current one are fine, |
3045 | rationale behind this is that you do not need to check for recursion in |
3083 | however. The rationale behind this is that you do not need to check |
3046 | those watchers, i.e. the sequence will always be \f(CW\*(C`ev_prepare\*(C'\fR, blocking, |
3084 | for recursion in those watchers, i.e. the sequence will always be |
3047 | \&\f(CW\*(C`ev_check\*(C'\fR so if you have one watcher of each kind they will always be |
3085 | \&\f(CW\*(C`ev_prepare\*(C'\fR, blocking, \f(CW\*(C`ev_check\*(C'\fR so if you have one watcher of each |
3048 | called in pairs bracketing the blocking call. |
3086 | kind they will always be called in pairs bracketing the blocking call. |
3049 | .PP |
3087 | .PP |
3050 | Their main purpose is to integrate other event mechanisms into libev and |
3088 | Their main purpose is to integrate other event mechanisms into libev and |
3051 | their use is somewhat advanced. They could be used, for example, to track |
3089 | their use is somewhat advanced. They could be used, for example, to track |
3052 | variable changes, implement your own watchers, integrate net-snmp or a |
3090 | variable changes, implement your own watchers, integrate net-snmp or a |
3053 | coroutine library and lots more. They are also occasionally useful if |
3091 | coroutine library and lots more. They are also occasionally useful if |
… | |
… | |
3223 | .Ve |
3261 | .Ve |
3224 | .PP |
3262 | .PP |
3225 | Method 4: Do not use a prepare or check watcher because the module you |
3263 | Method 4: Do not use a prepare or check watcher because the module you |
3226 | want to embed is not flexible enough to support it. Instead, you can |
3264 | want to embed is not flexible enough to support it. Instead, you can |
3227 | override their poll function. The drawback with this solution is that the |
3265 | override their poll function. The drawback with this solution is that the |
3228 | main loop is now no longer controllable by \s-1EV\s0. The \f(CW\*(C`Glib::EV\*(C'\fR module uses |
3266 | main loop is now no longer controllable by \s-1EV.\s0 The \f(CW\*(C`Glib::EV\*(C'\fR module uses |
3229 | this approach, effectively embedding \s-1EV\s0 as a client into the horrible |
3267 | this approach, effectively embedding \s-1EV\s0 as a client into the horrible |
3230 | libglib event loop. |
3268 | libglib event loop. |
3231 | .PP |
3269 | .PP |
3232 | .Vb 4 |
3270 | .Vb 4 |
3233 | \& static gint |
3271 | \& static gint |
… | |
… | |
3347 | .PP |
3385 | .PP |
3348 | .Vb 3 |
3386 | .Vb 3 |
3349 | \& struct ev_loop *loop_hi = ev_default_init (0); |
3387 | \& struct ev_loop *loop_hi = ev_default_init (0); |
3350 | \& struct ev_loop *loop_lo = 0; |
3388 | \& struct ev_loop *loop_lo = 0; |
3351 | \& ev_embed embed; |
3389 | \& ev_embed embed; |
3352 | \& |
3390 | \& |
3353 | \& // see if there is a chance of getting one that works |
3391 | \& // see if there is a chance of getting one that works |
3354 | \& // (remember that a flags value of 0 means autodetection) |
3392 | \& // (remember that a flags value of 0 means autodetection) |
3355 | \& loop_lo = ev_embeddable_backends () & ev_recommended_backends () |
3393 | \& loop_lo = ev_embeddable_backends () & ev_recommended_backends () |
3356 | \& ? ev_loop_new (ev_embeddable_backends () & ev_recommended_backends ()) |
3394 | \& ? ev_loop_new (ev_embeddable_backends () & ev_recommended_backends ()) |
3357 | \& : 0; |
3395 | \& : 0; |
… | |
… | |
3373 | .PP |
3411 | .PP |
3374 | .Vb 3 |
3412 | .Vb 3 |
3375 | \& struct ev_loop *loop = ev_default_init (0); |
3413 | \& struct ev_loop *loop = ev_default_init (0); |
3376 | \& struct ev_loop *loop_socket = 0; |
3414 | \& struct ev_loop *loop_socket = 0; |
3377 | \& ev_embed embed; |
3415 | \& ev_embed embed; |
3378 | \& |
3416 | \& |
3379 | \& if (ev_supported_backends () & ~ev_recommended_backends () & EVBACKEND_KQUEUE) |
3417 | \& if (ev_supported_backends () & ~ev_recommended_backends () & EVBACKEND_KQUEUE) |
3380 | \& if ((loop_socket = ev_loop_new (EVBACKEND_KQUEUE)) |
3418 | \& if ((loop_socket = ev_loop_new (EVBACKEND_KQUEUE)) |
3381 | \& { |
3419 | \& { |
3382 | \& ev_embed_init (&embed, 0, loop_socket); |
3420 | \& ev_embed_init (&embed, 0, loop_socket); |
3383 | \& ev_embed_start (loop, &embed); |
3421 | \& ev_embed_start (loop, &embed); |
… | |
… | |
3400 | of course. |
3438 | of course. |
3401 | .PP |
3439 | .PP |
3402 | \fIThe special problem of life after fork \- how is it possible?\fR |
3440 | \fIThe special problem of life after fork \- how is it possible?\fR |
3403 | .IX Subsection "The special problem of life after fork - how is it possible?" |
3441 | .IX Subsection "The special problem of life after fork - how is it possible?" |
3404 | .PP |
3442 | .PP |
3405 | Most uses of \f(CW\*(C`fork()\*(C'\fR consist of forking, then some simple calls to set |
3443 | Most uses of \f(CW\*(C`fork ()\*(C'\fR consist of forking, then some simple calls to set |
3406 | up/change the process environment, followed by a call to \f(CW\*(C`exec()\*(C'\fR. This |
3444 | up/change the process environment, followed by a call to \f(CW\*(C`exec()\*(C'\fR. This |
3407 | sequence should be handled by libev without any problems. |
3445 | sequence should be handled by libev without any problems. |
3408 | .PP |
3446 | .PP |
3409 | This changes when the application actually wants to do event handling |
3447 | This changes when the application actually wants to do event handling |
3410 | in the child, or both parent in child, in effect \*(L"continuing\*(R" after the |
3448 | in the child, or both parent in child, in effect \*(L"continuing\*(R" after the |
… | |
… | |
3627 | is a time window between the event loop checking and resetting the async |
3665 | is a time window between the event loop checking and resetting the async |
3628 | notification, and the callback being invoked. |
3666 | notification, and the callback being invoked. |
3629 | .SH "OTHER FUNCTIONS" |
3667 | .SH "OTHER FUNCTIONS" |
3630 | .IX Header "OTHER FUNCTIONS" |
3668 | .IX Header "OTHER FUNCTIONS" |
3631 | There are some other functions of possible interest. Described. Here. Now. |
3669 | There are some other functions of possible interest. Described. Here. Now. |
3632 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" 4 |
3670 | .IP "ev_once (loop, int fd, int events, ev_tstamp timeout, callback, arg)" 4 |
3633 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback)" |
3671 | .IX Item "ev_once (loop, int fd, int events, ev_tstamp timeout, callback, arg)" |
3634 | This function combines a simple timer and an I/O watcher, calls your |
3672 | This function combines a simple timer and an I/O watcher, calls your |
3635 | callback on whichever event happens first and automatically stops both |
3673 | callback on whichever event happens first and automatically stops both |
3636 | watchers. This is useful if you want to wait for a single event on an fd |
3674 | watchers. This is useful if you want to wait for a single event on an fd |
3637 | or timeout without having to allocate/configure/start/stop/free one or |
3675 | or timeout without having to allocate/configure/start/stop/free one or |
3638 | more watchers yourself. |
3676 | more watchers yourself. |
… | |
… | |
3650 | \&\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 |
3688 | \&\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 |
3651 | value passed to \f(CW\*(C`ev_once\*(C'\fR. Note that it is possible to receive \fIboth\fR |
3689 | value passed to \f(CW\*(C`ev_once\*(C'\fR. Note that it is possible to receive \fIboth\fR |
3652 | a timeout and an io event at the same time \- you probably should give io |
3690 | a timeout and an io event at the same time \- you probably should give io |
3653 | events precedence. |
3691 | events precedence. |
3654 | .Sp |
3692 | .Sp |
3655 | Example: wait up to ten seconds for data to appear on \s-1STDIN_FILENO\s0. |
3693 | Example: wait up to ten seconds for data to appear on \s-1STDIN_FILENO.\s0 |
3656 | .Sp |
3694 | .Sp |
3657 | .Vb 7 |
3695 | .Vb 7 |
3658 | \& static void stdin_ready (int revents, void *arg) |
3696 | \& static void stdin_ready (int revents, void *arg) |
3659 | \& { |
3697 | \& { |
3660 | \& if (revents & EV_READ) |
3698 | \& if (revents & EV_READ) |
… | |
… | |
3676 | .SH "COMMON OR USEFUL IDIOMS (OR BOTH)" |
3714 | .SH "COMMON OR USEFUL IDIOMS (OR BOTH)" |
3677 | .IX Header "COMMON OR USEFUL IDIOMS (OR BOTH)" |
3715 | .IX Header "COMMON OR USEFUL IDIOMS (OR BOTH)" |
3678 | This section explains some common idioms that are not immediately |
3716 | This section explains some common idioms that are not immediately |
3679 | obvious. Note that examples are sprinkled over the whole manual, and this |
3717 | obvious. Note that examples are sprinkled over the whole manual, and this |
3680 | section only contains stuff that wouldn't fit anywhere else. |
3718 | section only contains stuff that wouldn't fit anywhere else. |
3681 | .SS "\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0" |
3719 | .SS "\s-1ASSOCIATING CUSTOM DATA WITH A WATCHER\s0" |
3682 | .IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER" |
3720 | .IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER" |
3683 | Each watcher has, by default, a \f(CW\*(C`void *data\*(C'\fR member that you can read |
3721 | Each watcher has, by default, a \f(CW\*(C`void *data\*(C'\fR member that you can read |
3684 | or modify at any time: libev will completely ignore it. This can be used |
3722 | or modify at any time: libev will completely ignore it. This can be used |
3685 | to associate arbitrary data with your watcher. If you need more data and |
3723 | to associate arbitrary data with your watcher. If you need more data and |
3686 | don't want to allocate memory separately and store a pointer to it in that |
3724 | don't want to allocate memory separately and store a pointer to it in that |
… | |
… | |
3712 | \& } |
3750 | \& } |
3713 | .Ve |
3751 | .Ve |
3714 | .PP |
3752 | .PP |
3715 | More interesting and less C\-conformant ways of casting your callback |
3753 | More interesting and less C\-conformant ways of casting your callback |
3716 | function type instead have been omitted. |
3754 | function type instead have been omitted. |
3717 | .SS "\s-1BUILDING\s0 \s-1YOUR\s0 \s-1OWN\s0 \s-1COMPOSITE\s0 \s-1WATCHERS\s0" |
3755 | .SS "\s-1BUILDING YOUR OWN COMPOSITE WATCHERS\s0" |
3718 | .IX Subsection "BUILDING YOUR OWN COMPOSITE WATCHERS" |
3756 | .IX Subsection "BUILDING YOUR OWN COMPOSITE WATCHERS" |
3719 | Another common scenario is to use some data structure with multiple |
3757 | Another common scenario is to use some data structure with multiple |
3720 | embedded watchers, in effect creating your own watcher that combines |
3758 | embedded watchers, in effect creating your own watcher that combines |
3721 | multiple libev event sources into one \*(L"super-watcher\*(R": |
3759 | multiple libev event sources into one \*(L"super-watcher\*(R": |
3722 | .PP |
3760 | .PP |
… | |
… | |
3750 | \& { |
3788 | \& { |
3751 | \& struct my_biggy big = (struct my_biggy *) |
3789 | \& struct my_biggy big = (struct my_biggy *) |
3752 | \& (((char *)w) \- offsetof (struct my_biggy, t2)); |
3790 | \& (((char *)w) \- offsetof (struct my_biggy, t2)); |
3753 | \& } |
3791 | \& } |
3754 | .Ve |
3792 | .Ve |
3755 | .SS "\s-1AVOIDING\s0 \s-1FINISHING\s0 \s-1BEFORE\s0 \s-1RETURNING\s0" |
3793 | .SS "\s-1AVOIDING FINISHING BEFORE RETURNING\s0" |
3756 | .IX Subsection "AVOIDING FINISHING BEFORE RETURNING" |
3794 | .IX Subsection "AVOIDING FINISHING BEFORE RETURNING" |
3757 | Often you have structures like this in event-based programs: |
3795 | Often you have structures like this in event-based programs: |
3758 | .PP |
3796 | .PP |
3759 | .Vb 4 |
3797 | .Vb 4 |
3760 | \& callback () |
3798 | \& callback () |
… | |
… | |
3793 | \& ev_feed_event (EV_A_ watcher, 0); |
3831 | \& ev_feed_event (EV_A_ watcher, 0); |
3794 | .Ve |
3832 | .Ve |
3795 | .PP |
3833 | .PP |
3796 | This way, \f(CW\*(C`start_new_request\*(C'\fR can safely return before the callback is |
3834 | This way, \f(CW\*(C`start_new_request\*(C'\fR can safely return before the callback is |
3797 | invoked, while not delaying callback invocation too much. |
3835 | invoked, while not delaying callback invocation too much. |
3798 | .SS "\s-1MODEL/NESTED\s0 \s-1EVENT\s0 \s-1LOOP\s0 \s-1INVOCATIONS\s0 \s-1AND\s0 \s-1EXIT\s0 \s-1CONDITIONS\s0" |
3836 | .SS "\s-1MODEL/NESTED EVENT LOOP INVOCATIONS AND EXIT CONDITIONS\s0" |
3799 | .IX Subsection "MODEL/NESTED EVENT LOOP INVOCATIONS AND EXIT CONDITIONS" |
3837 | .IX Subsection "MODEL/NESTED EVENT LOOP INVOCATIONS AND EXIT CONDITIONS" |
3800 | Often (especially in \s-1GUI\s0 toolkits) there are places where you have |
3838 | Often (especially in \s-1GUI\s0 toolkits) there are places where you have |
3801 | \&\fImodal\fR interaction, which is most easily implemented by recursively |
3839 | \&\fImodal\fR interaction, which is most easily implemented by recursively |
3802 | invoking \f(CW\*(C`ev_run\*(C'\fR. |
3840 | invoking \f(CW\*(C`ev_run\*(C'\fR. |
3803 | .PP |
3841 | .PP |
… | |
… | |
3835 | \& exit_main_loop = 1; |
3873 | \& exit_main_loop = 1; |
3836 | \& |
3874 | \& |
3837 | \& // exit both |
3875 | \& // exit both |
3838 | \& exit_main_loop = exit_nested_loop = 1; |
3876 | \& exit_main_loop = exit_nested_loop = 1; |
3839 | .Ve |
3877 | .Ve |
3840 | .SS "\s-1THREAD\s0 \s-1LOCKING\s0 \s-1EXAMPLE\s0" |
3878 | .SS "\s-1THREAD LOCKING EXAMPLE\s0" |
3841 | .IX Subsection "THREAD LOCKING EXAMPLE" |
3879 | .IX Subsection "THREAD LOCKING EXAMPLE" |
3842 | Here is a fictitious example of how to run an event loop in a different |
3880 | Here is a fictitious example of how to run an event loop in a different |
3843 | thread from where callbacks are being invoked and watchers are |
3881 | thread from where callbacks are being invoked and watchers are |
3844 | created/added/removed. |
3882 | created/added/removed. |
3845 | .PP |
3883 | .PP |
… | |
… | |
3986 | .PP |
4024 | .PP |
3987 | Note that sending the \f(CW\*(C`ev_async\*(C'\fR watcher is required because otherwise |
4025 | Note that sending the \f(CW\*(C`ev_async\*(C'\fR watcher is required because otherwise |
3988 | an event loop currently blocking in the kernel will have no knowledge |
4026 | an event loop currently blocking in the kernel will have no knowledge |
3989 | about the newly added timer. By waking up the loop it will pick up any new |
4027 | about the newly added timer. By waking up the loop it will pick up any new |
3990 | watchers in the next event loop iteration. |
4028 | watchers in the next event loop iteration. |
3991 | .SS "\s-1THREADS\s0, \s-1COROUTINES\s0, \s-1CONTINUATIONS\s0, \s-1QUEUES\s0... \s-1INSTEAD\s0 \s-1OF\s0 \s-1CALLBACKS\s0" |
4029 | .SS "\s-1THREADS, COROUTINES, CONTINUATIONS, QUEUES... INSTEAD OF CALLBACKS\s0" |
3992 | .IX Subsection "THREADS, COROUTINES, CONTINUATIONS, QUEUES... INSTEAD OF CALLBACKS" |
4030 | .IX Subsection "THREADS, COROUTINES, CONTINUATIONS, QUEUES... INSTEAD OF CALLBACKS" |
3993 | While the overhead of a callback that e.g. schedules a thread is small, it |
4031 | While the overhead of a callback that e.g. schedules a thread is small, it |
3994 | is still an overhead. If you embed libev, and your main usage is with some |
4032 | is still an overhead. If you embed libev, and your main usage is with some |
3995 | kind of threads or coroutines, you might want to customise libev so that |
4033 | kind of threads or coroutines, you might want to customise libev so that |
3996 | doesn't need callbacks anymore. |
4034 | doesn't need callbacks anymore. |
… | |
… | |
4032 | You can do similar tricks if you have, say, threads with an event queue \- |
4070 | You can do similar tricks if you have, say, threads with an event queue \- |
4033 | instead of storing a coroutine, you store the queue object and instead of |
4071 | instead of storing a coroutine, you store the queue object and instead of |
4034 | switching to a coroutine, you push the watcher onto the queue and notify |
4072 | switching to a coroutine, you push the watcher onto the queue and notify |
4035 | any waiters. |
4073 | any waiters. |
4036 | .PP |
4074 | .PP |
4037 | To embed libev, see \*(L"\s-1EMBEDDING\s0\*(R", but in short, it's easiest to create two |
4075 | To embed libev, see \*(L"\s-1EMBEDDING\*(R"\s0, but in short, it's easiest to create two |
4038 | files, \fImy_ev.h\fR and \fImy_ev.c\fR that include the respective libev files: |
4076 | files, \fImy_ev.h\fR and \fImy_ev.c\fR that include the respective libev files: |
4039 | .PP |
4077 | .PP |
4040 | .Vb 4 |
4078 | .Vb 4 |
4041 | \& // my_ev.h |
4079 | \& // my_ev.h |
4042 | \& #define EV_CB_DECLARE(type) struct my_coro *cb; |
4080 | \& #define EV_CB_DECLARE(type) struct my_coro *cb; |
4043 | \& #define EV_CB_INVOKE(watcher) switch_to ((watcher)\->cb); |
4081 | \& #define EV_CB_INVOKE(watcher) switch_to ((watcher)\->cb) |
4044 | \& #include "../libev/ev.h" |
4082 | \& #include "../libev/ev.h" |
4045 | \& |
4083 | \& |
4046 | \& // my_ev.c |
4084 | \& // my_ev.c |
4047 | \& #define EV_H "my_ev.h" |
4085 | \& #define EV_H "my_ev.h" |
4048 | \& #include "../libev/ev.c" |
4086 | \& #include "../libev/ev.c" |
… | |
… | |
4088 | The normal C \s-1API\s0 should work fine when used from \*(C+: both ev.h and the |
4126 | The normal C \s-1API\s0 should work fine when used from \*(C+: both ev.h and the |
4089 | libev sources can be compiled as \*(C+. Therefore, code that uses the C \s-1API\s0 |
4127 | libev sources can be compiled as \*(C+. Therefore, code that uses the C \s-1API\s0 |
4090 | will work fine. |
4128 | will work fine. |
4091 | .PP |
4129 | .PP |
4092 | Proper exception specifications might have to be added to callbacks passed |
4130 | Proper exception specifications might have to be added to callbacks passed |
4093 | to libev: exceptions may be thrown only from watcher callbacks, all |
4131 | to libev: exceptions may be thrown only from watcher callbacks, all other |
4094 | other callbacks (allocator, syserr, loop acquire/release and periodic |
4132 | callbacks (allocator, syserr, loop acquire/release and periodic reschedule |
4095 | reschedule callbacks) must not throw exceptions, and might need a \f(CW\*(C`throw |
4133 | callbacks) must not throw exceptions, and might need a \f(CW\*(C`noexcept\*(C'\fR |
4096 | ()\*(C'\fR specification. If you have code that needs to be compiled as both C |
4134 | specification. If you have code that needs to be compiled as both C and |
4097 | and \*(C+ you can use the \f(CW\*(C`EV_THROW\*(C'\fR macro for this: |
4135 | \&\*(C+ you can use the \f(CW\*(C`EV_NOEXCEPT\*(C'\fR macro for this: |
4098 | .PP |
4136 | .PP |
4099 | .Vb 6 |
4137 | .Vb 6 |
4100 | \& static void |
4138 | \& static void |
4101 | \& fatal_error (const char *msg) EV_THROW |
4139 | \& fatal_error (const char *msg) EV_NOEXCEPT |
4102 | \& { |
4140 | \& { |
4103 | \& perror (msg); |
4141 | \& perror (msg); |
4104 | \& abort (); |
4142 | \& abort (); |
4105 | \& } |
4143 | \& } |
4106 | \& |
4144 | \& |
… | |
… | |
4234 | \& void operator() (ev::io &w, int revents) |
4272 | \& void operator() (ev::io &w, int revents) |
4235 | \& { |
4273 | \& { |
4236 | \& ... |
4274 | \& ... |
4237 | \& } |
4275 | \& } |
4238 | \& } |
4276 | \& } |
4239 | \& |
4277 | \& |
4240 | \& myfunctor f; |
4278 | \& myfunctor f; |
4241 | \& |
4279 | \& |
4242 | \& ev::io w; |
4280 | \& ev::io w; |
4243 | \& w.set (&f); |
4281 | \& w.set (&f); |
4244 | .Ve |
4282 | .Ve |
… | |
… | |
4337 | there are additional modules that implement libev-compatible interfaces |
4375 | there are additional modules that implement libev-compatible interfaces |
4338 | 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), |
4376 | 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), |
4339 | \&\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 |
4377 | \&\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 |
4340 | and \f(CW\*(C`EV::Glib\*(C'\fR). |
4378 | and \f(CW\*(C`EV::Glib\*(C'\fR). |
4341 | .Sp |
4379 | .Sp |
4342 | It can be found and installed via \s-1CPAN\s0, its homepage is at |
4380 | It can be found and installed via \s-1CPAN,\s0 its homepage is at |
4343 | <http://software.schmorp.de/pkg/EV>. |
4381 | <http://software.schmorp.de/pkg/EV>. |
4344 | .IP "Python" 4 |
4382 | .IP "Python" 4 |
4345 | .IX Item "Python" |
4383 | .IX Item "Python" |
4346 | Python bindings can be found at <http://code.google.com/p/pyev/>. It |
4384 | Python bindings can be found at <http://code.google.com/p/pyev/>. It |
4347 | seems to be quite complete and well-documented. |
4385 | seems to be quite complete and well-documented. |
… | |
… | |
4355 | Roger Pack reports that using the link order \f(CW\*(C`\-lws2_32 \-lmsvcrt\-ruby\-190\*(C'\fR |
4393 | Roger Pack reports that using the link order \f(CW\*(C`\-lws2_32 \-lmsvcrt\-ruby\-190\*(C'\fR |
4356 | makes rev work even on mingw. |
4394 | makes rev work even on mingw. |
4357 | .IP "Haskell" 4 |
4395 | .IP "Haskell" 4 |
4358 | .IX Item "Haskell" |
4396 | .IX Item "Haskell" |
4359 | A haskell binding to libev is available at |
4397 | A haskell binding to libev is available at |
4360 | http://hackage.haskell.org/cgi\-bin/hackage\-scripts/package/hlibev <http://hackage.haskell.org/cgi-bin/hackage-scripts/package/hlibev>. |
4398 | <http://hackage.haskell.org/cgi\-bin/hackage\-scripts/package/hlibev>. |
4361 | .IP "D" 4 |
4399 | .IP "D" 4 |
4362 | .IX Item "D" |
4400 | .IX Item "D" |
4363 | Leandro Lucarella has written a D language binding (\fIev.d\fR) for libev, to |
4401 | Leandro Lucarella has written a D language binding (\fIev.d\fR) for libev, to |
4364 | be found at <http://www.llucax.com.ar/proj/ev.d/index.html>. |
4402 | be found at <http://www.llucax.com.ar/proj/ev.d/index.html>. |
4365 | .IP "Ocaml" 4 |
4403 | .IP "Ocaml" 4 |
4366 | .IX Item "Ocaml" |
4404 | .IX Item "Ocaml" |
4367 | Erkki Seppala has written Ocaml bindings for libev, to be found at |
4405 | Erkki Seppala has written Ocaml bindings for libev, to be found at |
4368 | http://modeemi.cs.tut.fi/~flux/software/ocaml\-ev/ <http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>. |
4406 | <http://modeemi.cs.tut.fi/~flux/software/ocaml\-ev/>. |
4369 | .IP "Lua" 4 |
4407 | .IP "Lua" 4 |
4370 | .IX Item "Lua" |
4408 | .IX Item "Lua" |
4371 | Brian Maher has written a partial interface to libev for lua (at the |
4409 | Brian Maher has written a partial interface to libev for lua (at the |
4372 | time of this writing, only \f(CW\*(C`ev_io\*(C'\fR and \f(CW\*(C`ev_timer\*(C'\fR), to be found at |
4410 | time of this writing, only \f(CW\*(C`ev_io\*(C'\fR and \f(CW\*(C`ev_timer\*(C'\fR), to be found at |
4373 | http://github.com/brimworks/lua\-ev <http://github.com/brimworks/lua-ev>. |
4411 | <http://github.com/brimworks/lua\-ev>. |
4374 | .IP "Javascript" 4 |
4412 | .IP "Javascript" 4 |
4375 | .IX Item "Javascript" |
4413 | .IX Item "Javascript" |
4376 | Node.js (<http://nodejs.org>) uses libev as the underlying event library. |
4414 | Node.js (<http://nodejs.org>) uses libev as the underlying event library. |
4377 | .IP "Others" 4 |
4415 | .IP "Others" 4 |
4378 | .IX Item "Others" |
4416 | .IX Item "Others" |
… | |
… | |
4467 | .SS "\s-1FILESETS\s0" |
4505 | .SS "\s-1FILESETS\s0" |
4468 | .IX Subsection "FILESETS" |
4506 | .IX Subsection "FILESETS" |
4469 | Depending on what features you need you need to include one or more sets of files |
4507 | Depending on what features you need you need to include one or more sets of files |
4470 | in your application. |
4508 | in your application. |
4471 | .PP |
4509 | .PP |
4472 | \fI\s-1CORE\s0 \s-1EVENT\s0 \s-1LOOP\s0\fR |
4510 | \fI\s-1CORE EVENT LOOP\s0\fR |
4473 | .IX Subsection "CORE EVENT LOOP" |
4511 | .IX Subsection "CORE EVENT LOOP" |
4474 | .PP |
4512 | .PP |
4475 | To include only the libev core (all the \f(CW\*(C`ev_*\*(C'\fR functions), with manual |
4513 | To include only the libev core (all the \f(CW\*(C`ev_*\*(C'\fR functions), with manual |
4476 | configuration (no autoconf): |
4514 | configuration (no autoconf): |
4477 | .PP |
4515 | .PP |
… | |
… | |
4480 | \& #include "ev.c" |
4518 | \& #include "ev.c" |
4481 | .Ve |
4519 | .Ve |
4482 | .PP |
4520 | .PP |
4483 | This will automatically include \fIev.h\fR, too, and should be done in a |
4521 | This will automatically include \fIev.h\fR, too, and should be done in a |
4484 | single C source file only to provide the function implementations. To use |
4522 | single C source file only to provide the function implementations. To use |
4485 | it, do the same for \fIev.h\fR in all files wishing to use this \s-1API\s0 (best |
4523 | it, do the same for \fIev.h\fR in all files wishing to use this \s-1API \s0(best |
4486 | done by writing a wrapper around \fIev.h\fR that you can include instead and |
4524 | done by writing a wrapper around \fIev.h\fR that you can include instead and |
4487 | where you can put other configuration options): |
4525 | where you can put other configuration options): |
4488 | .PP |
4526 | .PP |
4489 | .Vb 2 |
4527 | .Vb 2 |
4490 | \& #define EV_STANDALONE 1 |
4528 | \& #define EV_STANDALONE 1 |
… | |
… | |
4504 | \& ev_vars.h |
4542 | \& ev_vars.h |
4505 | \& ev_wrap.h |
4543 | \& ev_wrap.h |
4506 | \& |
4544 | \& |
4507 | \& ev_win32.c required on win32 platforms only |
4545 | \& ev_win32.c required on win32 platforms only |
4508 | \& |
4546 | \& |
4509 | \& ev_select.c only when select backend is enabled (which is enabled by default) |
4547 | \& ev_select.c only when select backend is enabled |
4510 | \& ev_poll.c only when poll backend is enabled (disabled by default) |
4548 | \& ev_poll.c only when poll backend is enabled |
4511 | \& ev_epoll.c only when the epoll backend is enabled (disabled by default) |
4549 | \& ev_epoll.c only when the epoll backend is enabled |
4512 | \& ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
4550 | \& ev_kqueue.c only when the kqueue backend is enabled |
4513 | \& ev_port.c only when the solaris port backend is enabled (disabled by default) |
4551 | \& ev_port.c only when the solaris port backend is enabled |
4514 | .Ve |
4552 | .Ve |
4515 | .PP |
4553 | .PP |
4516 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
4554 | \&\fIev.c\fR includes the backend files directly when enabled, so you only need |
4517 | to compile this single file. |
4555 | to compile this single file. |
4518 | .PP |
4556 | .PP |
4519 | \fI\s-1LIBEVENT\s0 \s-1COMPATIBILITY\s0 \s-1API\s0\fR |
4557 | \fI\s-1LIBEVENT COMPATIBILITY API\s0\fR |
4520 | .IX Subsection "LIBEVENT COMPATIBILITY API" |
4558 | .IX Subsection "LIBEVENT COMPATIBILITY API" |
4521 | .PP |
4559 | .PP |
4522 | To include the libevent compatibility \s-1API\s0, also include: |
4560 | To include the libevent compatibility \s-1API,\s0 also include: |
4523 | .PP |
4561 | .PP |
4524 | .Vb 1 |
4562 | .Vb 1 |
4525 | \& #include "event.c" |
4563 | \& #include "event.c" |
4526 | .Ve |
4564 | .Ve |
4527 | .PP |
4565 | .PP |
… | |
… | |
4529 | .PP |
4567 | .PP |
4530 | .Vb 1 |
4568 | .Vb 1 |
4531 | \& #include "event.h" |
4569 | \& #include "event.h" |
4532 | .Ve |
4570 | .Ve |
4533 | .PP |
4571 | .PP |
4534 | in the files that want to use the libevent \s-1API\s0. This also includes \fIev.h\fR. |
4572 | in the files that want to use the libevent \s-1API.\s0 This also includes \fIev.h\fR. |
4535 | .PP |
4573 | .PP |
4536 | You need the following additional files for this: |
4574 | You need the following additional files for this: |
4537 | .PP |
4575 | .PP |
4538 | .Vb 2 |
4576 | .Vb 2 |
4539 | \& event.h |
4577 | \& event.h |
4540 | \& event.c |
4578 | \& event.c |
4541 | .Ve |
4579 | .Ve |
4542 | .PP |
4580 | .PP |
4543 | \fI\s-1AUTOCONF\s0 \s-1SUPPORT\s0\fR |
4581 | \fI\s-1AUTOCONF SUPPORT\s0\fR |
4544 | .IX Subsection "AUTOCONF SUPPORT" |
4582 | .IX Subsection "AUTOCONF SUPPORT" |
4545 | .PP |
4583 | .PP |
4546 | Instead of using \f(CW\*(C`EV_STANDALONE=1\*(C'\fR and providing your configuration in |
4584 | Instead of using \f(CW\*(C`EV_STANDALONE=1\*(C'\fR and providing your configuration in |
4547 | whatever way you want, you can also \f(CW\*(C`m4_include([libev.m4])\*(C'\fR in your |
4585 | whatever way you want, you can also \f(CW\*(C`m4_include([libev.m4])\*(C'\fR in your |
4548 | \&\fIconfigure.ac\fR and leave \f(CW\*(C`EV_STANDALONE\*(C'\fR undefined. \fIev.c\fR will then |
4586 | \&\fIconfigure.ac\fR and leave \f(CW\*(C`EV_STANDALONE\*(C'\fR undefined. \fIev.c\fR will then |
… | |
… | |
4551 | For this of course you need the m4 file: |
4589 | For this of course you need the m4 file: |
4552 | .PP |
4590 | .PP |
4553 | .Vb 1 |
4591 | .Vb 1 |
4554 | \& libev.m4 |
4592 | \& libev.m4 |
4555 | .Ve |
4593 | .Ve |
4556 | .SS "\s-1PREPROCESSOR\s0 \s-1SYMBOLS/MACROS\s0" |
4594 | .SS "\s-1PREPROCESSOR SYMBOLS/MACROS\s0" |
4557 | .IX Subsection "PREPROCESSOR SYMBOLS/MACROS" |
4595 | .IX Subsection "PREPROCESSOR SYMBOLS/MACROS" |
4558 | Libev can be configured via a variety of preprocessor symbols you have to |
4596 | Libev can be configured via a variety of preprocessor symbols you have to |
4559 | define before including (or compiling) any of its files. The default in |
4597 | define before including (or compiling) any of its files. The default in |
4560 | the absence of autoconf is documented for every option. |
4598 | the absence of autoconf is documented for every option. |
4561 | .PP |
4599 | .PP |
4562 | Symbols marked with \*(L"(h)\*(R" do not change the \s-1ABI\s0, and can have different |
4600 | Symbols marked with \*(L"(h)\*(R" do not change the \s-1ABI,\s0 and can have different |
4563 | values when compiling libev vs. including \fIev.h\fR, so it is permissible |
4601 | values when compiling libev vs. including \fIev.h\fR, so it is permissible |
4564 | to redefine them before including \fIev.h\fR without breaking compatibility |
4602 | to redefine them before including \fIev.h\fR without breaking compatibility |
4565 | to a compiled library. All other symbols change the \s-1ABI\s0, which means all |
4603 | to a compiled library. All other symbols change the \s-1ABI,\s0 which means all |
4566 | users of libev and the libev code itself must be compiled with compatible |
4604 | users of libev and the libev code itself must be compiled with compatible |
4567 | settings. |
4605 | settings. |
4568 | .IP "\s-1EV_COMPAT3\s0 (h)" 4 |
4606 | .IP "\s-1EV_COMPAT3 \s0(h)" 4 |
4569 | .IX Item "EV_COMPAT3 (h)" |
4607 | .IX Item "EV_COMPAT3 (h)" |
4570 | Backwards compatibility is a major concern for libev. This is why this |
4608 | Backwards compatibility is a major concern for libev. This is why this |
4571 | release of libev comes with wrappers for the functions and symbols that |
4609 | release of libev comes with wrappers for the functions and symbols that |
4572 | have been renamed between libev version 3 and 4. |
4610 | have been renamed between libev version 3 and 4. |
4573 | .Sp |
4611 | .Sp |
… | |
… | |
4578 | typedef in that case. |
4616 | typedef in that case. |
4579 | .Sp |
4617 | .Sp |
4580 | In some future version, the default for \f(CW\*(C`EV_COMPAT3\*(C'\fR will become \f(CW0\fR, |
4618 | In some future version, the default for \f(CW\*(C`EV_COMPAT3\*(C'\fR will become \f(CW0\fR, |
4581 | and in some even more future version the compatibility code will be |
4619 | and in some even more future version the compatibility code will be |
4582 | removed completely. |
4620 | removed completely. |
4583 | .IP "\s-1EV_STANDALONE\s0 (h)" 4 |
4621 | .IP "\s-1EV_STANDALONE \s0(h)" 4 |
4584 | .IX Item "EV_STANDALONE (h)" |
4622 | .IX Item "EV_STANDALONE (h)" |
4585 | Must always be \f(CW1\fR if you do not use autoconf configuration, which |
4623 | Must always be \f(CW1\fR if you do not use autoconf configuration, which |
4586 | keeps libev from including \fIconfig.h\fR, and it also defines dummy |
4624 | keeps libev from including \fIconfig.h\fR, and it also defines dummy |
4587 | implementations for some libevent functions (such as logging, which is not |
4625 | implementations for some libevent functions (such as logging, which is not |
4588 | supported). It will also not define any of the structs usually found in |
4626 | supported). It will also not define any of the structs usually found in |
… | |
… | |
4731 | between threads, that is, threads can be used, but threads never run on |
4769 | between threads, that is, threads can be used, but threads never run on |
4732 | different cpus (or different cpu cores). This reduces dependencies |
4770 | different cpus (or different cpu cores). This reduces dependencies |
4733 | and makes libev faster. |
4771 | and makes libev faster. |
4734 | .IP "\s-1EV_NO_THREADS\s0" 4 |
4772 | .IP "\s-1EV_NO_THREADS\s0" 4 |
4735 | .IX Item "EV_NO_THREADS" |
4773 | .IX Item "EV_NO_THREADS" |
4736 | If defined to be \f(CW1\fR, libev will assume that it will never be called |
4774 | If defined to be \f(CW1\fR, libev will assume that it will never be called from |
4737 | from different threads, which is a stronger assumption than \f(CW\*(C`EV_NO_SMP\*(C'\fR, |
4775 | different threads (that includes signal handlers), which is a stronger |
4738 | above. This reduces dependencies and makes libev faster. |
4776 | assumption than \f(CW\*(C`EV_NO_SMP\*(C'\fR, above. This reduces dependencies and makes |
|
|
4777 | libev faster. |
4739 | .IP "\s-1EV_ATOMIC_T\s0" 4 |
4778 | .IP "\s-1EV_ATOMIC_T\s0" 4 |
4740 | .IX Item "EV_ATOMIC_T" |
4779 | .IX Item "EV_ATOMIC_T" |
4741 | Libev requires an integer type (suitable for storing \f(CW0\fR or \f(CW1\fR) whose |
4780 | Libev requires an integer type (suitable for storing \f(CW0\fR or \f(CW1\fR) whose |
4742 | access is atomic with respect to other threads or signal contexts. No |
4781 | access is atomic with respect to other threads or signal contexts. No |
4743 | such type is easily found in the C language, so you can provide your own |
4782 | such type is easily found in the C language, so you can provide your own |
… | |
… | |
4745 | handler \*(L"locking\*(R" as well as for signal and thread safety in \f(CW\*(C`ev_async\*(C'\fR |
4784 | handler \*(L"locking\*(R" as well as for signal and thread safety in \f(CW\*(C`ev_async\*(C'\fR |
4746 | watchers. |
4785 | watchers. |
4747 | .Sp |
4786 | .Sp |
4748 | In the absence of this define, libev will use \f(CW\*(C`sig_atomic_t volatile\*(C'\fR |
4787 | In the absence of this define, libev will use \f(CW\*(C`sig_atomic_t volatile\*(C'\fR |
4749 | (from \fIsignal.h\fR), which is usually good enough on most platforms. |
4788 | (from \fIsignal.h\fR), which is usually good enough on most platforms. |
4750 | .IP "\s-1EV_H\s0 (h)" 4 |
4789 | .IP "\s-1EV_H \s0(h)" 4 |
4751 | .IX Item "EV_H (h)" |
4790 | .IX Item "EV_H (h)" |
4752 | The name of the \fIev.h\fR header file used to include it. The default if |
4791 | The name of the \fIev.h\fR header file used to include it. The default if |
4753 | undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be |
4792 | undefined is \f(CW"ev.h"\fR in \fIevent.h\fR, \fIev.c\fR and \fIev++.h\fR. This can be |
4754 | used to virtually rename the \fIev.h\fR header file in case of conflicts. |
4793 | used to virtually rename the \fIev.h\fR header file in case of conflicts. |
4755 | .IP "\s-1EV_CONFIG_H\s0 (h)" 4 |
4794 | .IP "\s-1EV_CONFIG_H \s0(h)" 4 |
4756 | .IX Item "EV_CONFIG_H (h)" |
4795 | .IX Item "EV_CONFIG_H (h)" |
4757 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
4796 | If \f(CW\*(C`EV_STANDALONE\*(C'\fR isn't \f(CW1\fR, this variable can be used to override |
4758 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
4797 | \&\fIev.c\fR's idea of where to find the \fIconfig.h\fR file, similarly to |
4759 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
4798 | \&\f(CW\*(C`EV_H\*(C'\fR, above. |
4760 | .IP "\s-1EV_EVENT_H\s0 (h)" 4 |
4799 | .IP "\s-1EV_EVENT_H \s0(h)" 4 |
4761 | .IX Item "EV_EVENT_H (h)" |
4800 | .IX Item "EV_EVENT_H (h)" |
4762 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
4801 | Similarly to \f(CW\*(C`EV_H\*(C'\fR, this macro can be used to override \fIevent.c\fR's idea |
4763 | of how the \fIevent.h\fR header can be found, the default is \f(CW"event.h"\fR. |
4802 | of how the \fIevent.h\fR header can be found, the default is \f(CW"event.h"\fR. |
4764 | .IP "\s-1EV_PROTOTYPES\s0 (h)" 4 |
4803 | .IP "\s-1EV_PROTOTYPES \s0(h)" 4 |
4765 | .IX Item "EV_PROTOTYPES (h)" |
4804 | .IX Item "EV_PROTOTYPES (h)" |
4766 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
4805 | If defined to be \f(CW0\fR, then \fIev.h\fR will not define any function |
4767 | prototypes, but still define all the structs and other symbols. This is |
4806 | prototypes, but still define all the structs and other symbols. This is |
4768 | occasionally useful if you want to provide your own wrapper functions |
4807 | occasionally useful if you want to provide your own wrapper functions |
4769 | around libev functions. |
4808 | around libev functions. |
… | |
… | |
4793 | all the priorities, so having many of them (hundreds) uses a lot of space |
4832 | all the priorities, so having many of them (hundreds) uses a lot of space |
4794 | and time, so using the defaults of five priorities (\-2 .. +2) is usually |
4833 | and time, so using the defaults of five priorities (\-2 .. +2) is usually |
4795 | fine. |
4834 | fine. |
4796 | .Sp |
4835 | .Sp |
4797 | If your embedding application does not need any priorities, defining these |
4836 | If your embedding application does not need any priorities, defining these |
4798 | both to \f(CW0\fR will save some memory and \s-1CPU\s0. |
4837 | both to \f(CW0\fR will save some memory and \s-1CPU.\s0 |
4799 | .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 |
4838 | .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 |
4800 | .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." |
4839 | .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." |
4801 | If undefined or defined to be \f(CW1\fR (and the platform supports it), then |
4840 | If undefined or defined to be \f(CW1\fR (and the platform supports it), then |
4802 | the respective watcher type is supported. If defined to be \f(CW0\fR, then it |
4841 | the respective watcher type is supported. If defined to be \f(CW0\fR, then it |
4803 | is not. Disabling watcher types mainly saves code size. |
4842 | is not. Disabling watcher types mainly saves code size. |
4804 | .IP "\s-1EV_FEATURES\s0" 4 |
4843 | .IP "\s-1EV_FEATURES\s0" 4 |
… | |
… | |
4978 | .Vb 3 |
5017 | .Vb 3 |
4979 | \& #define EV_COMMON \e |
5018 | \& #define EV_COMMON \e |
4980 | \& SV *self; /* contains this struct */ \e |
5019 | \& SV *self; /* contains this struct */ \e |
4981 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
5020 | \& SV *cb_sv, *fh /* note no trailing ";" */ |
4982 | .Ve |
5021 | .Ve |
4983 | .IP "\s-1EV_CB_DECLARE\s0 (type)" 4 |
5022 | .IP "\s-1EV_CB_DECLARE \s0(type)" 4 |
4984 | .IX Item "EV_CB_DECLARE (type)" |
5023 | .IX Item "EV_CB_DECLARE (type)" |
4985 | .PD 0 |
5024 | .PD 0 |
4986 | .IP "\s-1EV_CB_INVOKE\s0 (watcher, revents)" 4 |
5025 | .IP "\s-1EV_CB_INVOKE \s0(watcher, revents)" 4 |
4987 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
5026 | .IX Item "EV_CB_INVOKE (watcher, revents)" |
4988 | .IP "ev_set_cb (ev, cb)" 4 |
5027 | .IP "ev_set_cb (ev, cb)" 4 |
4989 | .IX Item "ev_set_cb (ev, cb)" |
5028 | .IX Item "ev_set_cb (ev, cb)" |
4990 | .PD |
5029 | .PD |
4991 | Can be used to change the callback member declaration in each watcher, |
5030 | Can be used to change the callback member declaration in each watcher, |
4992 | and the way callbacks are invoked and set. Must expand to a struct member |
5031 | and the way callbacks are invoked and set. Must expand to a struct member |
4993 | definition and a statement, respectively. See the \fIev.h\fR header file for |
5032 | definition and a statement, respectively. See the \fIev.h\fR header file for |
4994 | their default definitions. One possible use for overriding these is to |
5033 | their default definitions. One possible use for overriding these is to |
4995 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
5034 | avoid the \f(CW\*(C`struct ev_loop *\*(C'\fR as first argument in all cases, or to use |
4996 | method calls instead of plain function calls in \*(C+. |
5035 | method calls instead of plain function calls in \*(C+. |
4997 | .SS "\s-1EXPORTED\s0 \s-1API\s0 \s-1SYMBOLS\s0" |
5036 | .SS "\s-1EXPORTED API SYMBOLS\s0" |
4998 | .IX Subsection "EXPORTED API SYMBOLS" |
5037 | .IX Subsection "EXPORTED API SYMBOLS" |
4999 | If you need to re-export the \s-1API\s0 (e.g. via a \s-1DLL\s0) and you need a list of |
5038 | If you need to re-export the \s-1API \s0(e.g. via a \s-1DLL\s0) and you need a list of |
5000 | exported symbols, you can use the provided \fISymbol.*\fR files which list |
5039 | exported symbols, you can use the provided \fISymbol.*\fR files which list |
5001 | all public symbols, one per line: |
5040 | all public symbols, one per line: |
5002 | .PP |
5041 | .PP |
5003 | .Vb 2 |
5042 | .Vb 2 |
5004 | \& Symbols.ev for libev proper |
5043 | \& Symbols.ev for libev proper |
… | |
… | |
5056 | \& #include "ev_cpp.h" |
5095 | \& #include "ev_cpp.h" |
5057 | \& #include "ev.c" |
5096 | \& #include "ev.c" |
5058 | .Ve |
5097 | .Ve |
5059 | .SH "INTERACTION WITH OTHER PROGRAMS, LIBRARIES OR THE ENVIRONMENT" |
5098 | .SH "INTERACTION WITH OTHER PROGRAMS, LIBRARIES OR THE ENVIRONMENT" |
5060 | .IX Header "INTERACTION WITH OTHER PROGRAMS, LIBRARIES OR THE ENVIRONMENT" |
5099 | .IX Header "INTERACTION WITH OTHER PROGRAMS, LIBRARIES OR THE ENVIRONMENT" |
5061 | .SS "\s-1THREADS\s0 \s-1AND\s0 \s-1COROUTINES\s0" |
5100 | .SS "\s-1THREADS AND COROUTINES\s0" |
5062 | .IX Subsection "THREADS AND COROUTINES" |
5101 | .IX Subsection "THREADS AND COROUTINES" |
5063 | \fI\s-1THREADS\s0\fR |
5102 | \fI\s-1THREADS\s0\fR |
5064 | .IX Subsection "THREADS" |
5103 | .IX Subsection "THREADS" |
5065 | .PP |
5104 | .PP |
5066 | All libev functions are reentrant and thread-safe unless explicitly |
5105 | All libev functions are reentrant and thread-safe unless explicitly |
… | |
… | |
5112 | An example use would be to communicate signals or other events that only |
5151 | An example use would be to communicate signals or other events that only |
5113 | work in the default loop by registering the signal watcher with the |
5152 | work in the default loop by registering the signal watcher with the |
5114 | default loop and triggering an \f(CW\*(C`ev_async\*(C'\fR watcher from the default loop |
5153 | default loop and triggering an \f(CW\*(C`ev_async\*(C'\fR watcher from the default loop |
5115 | watcher callback into the event loop interested in the signal. |
5154 | watcher callback into the event loop interested in the signal. |
5116 | .PP |
5155 | .PP |
5117 | See also \*(L"\s-1THREAD\s0 \s-1LOCKING\s0 \s-1EXAMPLE\s0\*(R". |
5156 | See also \*(L"\s-1THREAD LOCKING EXAMPLE\*(R"\s0. |
5118 | .PP |
5157 | .PP |
5119 | \fI\s-1COROUTINES\s0\fR |
5158 | \fI\s-1COROUTINES\s0\fR |
5120 | .IX Subsection "COROUTINES" |
5159 | .IX Subsection "COROUTINES" |
5121 | .PP |
5160 | .PP |
5122 | Libev is very accommodating to coroutines (\*(L"cooperative threads\*(R"): |
5161 | Libev is very accommodating to coroutines (\*(L"cooperative threads\*(R"): |
… | |
… | |
5127 | that you must not do this from \f(CW\*(C`ev_periodic\*(C'\fR reschedule callbacks. |
5166 | that you must not do this from \f(CW\*(C`ev_periodic\*(C'\fR reschedule callbacks. |
5128 | .PP |
5167 | .PP |
5129 | Care has been taken to ensure that libev does not keep local state inside |
5168 | Care has been taken to ensure that libev does not keep local state inside |
5130 | \&\f(CW\*(C`ev_run\*(C'\fR, and other calls do not usually allow for coroutine switches as |
5169 | \&\f(CW\*(C`ev_run\*(C'\fR, and other calls do not usually allow for coroutine switches as |
5131 | they do not call any callbacks. |
5170 | they do not call any callbacks. |
5132 | .SS "\s-1COMPILER\s0 \s-1WARNINGS\s0" |
5171 | .SS "\s-1COMPILER WARNINGS\s0" |
5133 | .IX Subsection "COMPILER WARNINGS" |
5172 | .IX Subsection "COMPILER WARNINGS" |
5134 | Depending on your compiler and compiler settings, you might get no or a |
5173 | Depending on your compiler and compiler settings, you might get no or a |
5135 | lot of warnings when compiling libev code. Some people are apparently |
5174 | lot of warnings when compiling libev code. Some people are apparently |
5136 | scared by this. |
5175 | scared by this. |
5137 | .PP |
5176 | .PP |
… | |
… | |
5189 | .PP |
5228 | .PP |
5190 | If you need, for some reason, empty reports from valgrind for your project |
5229 | If you need, for some reason, empty reports from valgrind for your project |
5191 | I suggest using suppression lists. |
5230 | I suggest using suppression lists. |
5192 | .SH "PORTABILITY NOTES" |
5231 | .SH "PORTABILITY NOTES" |
5193 | .IX Header "PORTABILITY NOTES" |
5232 | .IX Header "PORTABILITY NOTES" |
5194 | .SS "\s-1GNU/LINUX\s0 32 \s-1BIT\s0 \s-1LIMITATIONS\s0" |
5233 | .SS "\s-1GNU/LINUX 32 BIT LIMITATIONS\s0" |
5195 | .IX Subsection "GNU/LINUX 32 BIT LIMITATIONS" |
5234 | .IX Subsection "GNU/LINUX 32 BIT LIMITATIONS" |
5196 | GNU/Linux is the only common platform that supports 64 bit file/large file |
5235 | GNU/Linux is the only common platform that supports 64 bit file/large file |
5197 | interfaces but \fIdisables\fR them by default. |
5236 | interfaces but \fIdisables\fR them by default. |
5198 | .PP |
5237 | .PP |
5199 | That means that libev compiled in the default environment doesn't support |
5238 | That means that libev compiled in the default environment doesn't support |
5200 | files larger than 2GiB or so, which mainly affects \f(CW\*(C`ev_stat\*(C'\fR watchers. |
5239 | files larger than 2GiB or so, which mainly affects \f(CW\*(C`ev_stat\*(C'\fR watchers. |
5201 | .PP |
5240 | .PP |
5202 | Unfortunately, many programs try to work around this GNU/Linux issue |
5241 | Unfortunately, many programs try to work around this GNU/Linux issue |
5203 | by enabling the large file \s-1API\s0, which makes them incompatible with the |
5242 | by enabling the large file \s-1API,\s0 which makes them incompatible with the |
5204 | standard libev compiled for their system. |
5243 | standard libev compiled for their system. |
5205 | .PP |
5244 | .PP |
5206 | Likewise, libev cannot enable the large file \s-1API\s0 itself as this would |
5245 | Likewise, libev cannot enable the large file \s-1API\s0 itself as this would |
5207 | suddenly make it incompatible to the default compile time environment, |
5246 | suddenly make it incompatible to the default compile time environment, |
5208 | i.e. all programs not using special compile switches. |
5247 | i.e. all programs not using special compile switches. |
5209 | .SS "\s-1OS/X\s0 \s-1AND\s0 \s-1DARWIN\s0 \s-1BUGS\s0" |
5248 | .SS "\s-1OS/X AND DARWIN BUGS\s0" |
5210 | .IX Subsection "OS/X AND DARWIN BUGS" |
5249 | .IX Subsection "OS/X AND DARWIN BUGS" |
5211 | The whole thing is a bug if you ask me \- basically any system interface |
5250 | The whole thing is a bug if you ask me \- basically any system interface |
5212 | you touch is broken, whether it is locales, poll, kqueue or even the |
5251 | you touch is broken, whether it is locales, poll, kqueue or even the |
5213 | OpenGL drivers. |
5252 | OpenGL drivers. |
5214 | .PP |
5253 | .PP |
… | |
… | |
5236 | .PP |
5275 | .PP |
5237 | \fI\f(CI\*(C`select\*(C'\fI is buggy\fR |
5276 | \fI\f(CI\*(C`select\*(C'\fI is buggy\fR |
5238 | .IX Subsection "select is buggy" |
5277 | .IX Subsection "select is buggy" |
5239 | .PP |
5278 | .PP |
5240 | All that's left is \f(CW\*(C`select\*(C'\fR, and of course Apple found a way to fuck this |
5279 | All that's left is \f(CW\*(C`select\*(C'\fR, and of course Apple found a way to fuck this |
5241 | one up as well: On \s-1OS/X\s0, \f(CW\*(C`select\*(C'\fR actively limits the number of file |
5280 | one up as well: On \s-1OS/X, \s0\f(CW\*(C`select\*(C'\fR actively limits the number of file |
5242 | descriptors you can pass in to 1024 \- your program suddenly crashes when |
5281 | descriptors you can pass in to 1024 \- your program suddenly crashes when |
5243 | you use more. |
5282 | you use more. |
5244 | .PP |
5283 | .PP |
5245 | There is an undocumented \*(L"workaround\*(R" for this \- defining |
5284 | There is an undocumented \*(L"workaround\*(R" for this \- defining |
5246 | \&\f(CW\*(C`_DARWIN_UNLIMITED_SELECT\*(C'\fR, which libev tries to use, so select \fIshould\fR |
5285 | \&\f(CW\*(C`_DARWIN_UNLIMITED_SELECT\*(C'\fR, which libev tries to use, so select \fIshould\fR |
5247 | work on \s-1OS/X\s0. |
5286 | work on \s-1OS/X.\s0 |
5248 | .SS "\s-1SOLARIS\s0 \s-1PROBLEMS\s0 \s-1AND\s0 \s-1WORKAROUNDS\s0" |
5287 | .SS "\s-1SOLARIS PROBLEMS AND WORKAROUNDS\s0" |
5249 | .IX Subsection "SOLARIS PROBLEMS AND WORKAROUNDS" |
5288 | .IX Subsection "SOLARIS PROBLEMS AND WORKAROUNDS" |
5250 | \fI\f(CI\*(C`errno\*(C'\fI reentrancy\fR |
5289 | \fI\f(CI\*(C`errno\*(C'\fI reentrancy\fR |
5251 | .IX Subsection "errno reentrancy" |
5290 | .IX Subsection "errno reentrancy" |
5252 | .PP |
5291 | .PP |
5253 | The default compile environment on Solaris is unfortunately so |
5292 | The default compile environment on Solaris is unfortunately so |
… | |
… | |
5270 | great. |
5309 | great. |
5271 | .PP |
5310 | .PP |
5272 | If you can't get it to work, you can try running the program by setting |
5311 | If you can't get it to work, you can try running the program by setting |
5273 | the environment variable \f(CW\*(C`LIBEV_FLAGS=3\*(C'\fR to only allow \f(CW\*(C`poll\*(C'\fR and |
5312 | the environment variable \f(CW\*(C`LIBEV_FLAGS=3\*(C'\fR to only allow \f(CW\*(C`poll\*(C'\fR and |
5274 | \&\f(CW\*(C`select\*(C'\fR backends. |
5313 | \&\f(CW\*(C`select\*(C'\fR backends. |
5275 | .SS "\s-1AIX\s0 \s-1POLL\s0 \s-1BUG\s0" |
5314 | .SS "\s-1AIX POLL BUG\s0" |
5276 | .IX Subsection "AIX POLL BUG" |
5315 | .IX Subsection "AIX POLL BUG" |
5277 | \&\s-1AIX\s0 unfortunately has a broken \f(CW\*(C`poll.h\*(C'\fR header. Libev works around |
5316 | \&\s-1AIX\s0 unfortunately has a broken \f(CW\*(C`poll.h\*(C'\fR header. Libev works around |
5278 | this by trying to avoid the poll backend altogether (i.e. it's not even |
5317 | this by trying to avoid the poll backend altogether (i.e. it's not even |
5279 | compiled in), which normally isn't a big problem as \f(CW\*(C`select\*(C'\fR works fine |
5318 | compiled in), which normally isn't a big problem as \f(CW\*(C`select\*(C'\fR works fine |
5280 | with large bitsets on \s-1AIX\s0, and \s-1AIX\s0 is dead anyway. |
5319 | with large bitsets on \s-1AIX,\s0 and \s-1AIX\s0 is dead anyway. |
5281 | .SS "\s-1WIN32\s0 \s-1PLATFORM\s0 \s-1LIMITATIONS\s0 \s-1AND\s0 \s-1WORKAROUNDS\s0" |
5320 | .SS "\s-1WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS\s0" |
5282 | .IX Subsection "WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS" |
5321 | .IX Subsection "WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS" |
5283 | \fIGeneral issues\fR |
5322 | \fIGeneral issues\fR |
5284 | .IX Subsection "General issues" |
5323 | .IX Subsection "General issues" |
5285 | .PP |
5324 | .PP |
5286 | Win32 doesn't support any of the standards (e.g. \s-1POSIX\s0) that libev |
5325 | Win32 doesn't support any of the standards (e.g. \s-1POSIX\s0) that libev |
… | |
… | |
5355 | \& #define EV_USE_SELECT 1 |
5394 | \& #define EV_USE_SELECT 1 |
5356 | \& #define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */ |
5395 | \& #define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */ |
5357 | .Ve |
5396 | .Ve |
5358 | .PP |
5397 | .PP |
5359 | Note that winsockets handling of fd sets is O(n), so you can easily get a |
5398 | Note that winsockets handling of fd sets is O(n), so you can easily get a |
5360 | complexity in the O(nA\*^X) range when using win32. |
5399 | complexity in the O(nX) range when using win32. |
5361 | .PP |
5400 | .PP |
5362 | \fILimited number of file descriptors\fR |
5401 | \fILimited number of file descriptors\fR |
5363 | .IX Subsection "Limited number of file descriptors" |
5402 | .IX Subsection "Limited number of file descriptors" |
5364 | .PP |
5403 | .PP |
5365 | Windows has numerous arbitrary (and low) limits on things. |
5404 | Windows has numerous arbitrary (and low) limits on things. |
… | |
… | |
5381 | by calling \f(CW\*(C`_setmaxstdio\*(C'\fR, which can increase this limit to \f(CW2048\fR |
5420 | by calling \f(CW\*(C`_setmaxstdio\*(C'\fR, which can increase this limit to \f(CW2048\fR |
5382 | (another arbitrary limit), but is broken in many versions of the Microsoft |
5421 | (another arbitrary limit), but is broken in many versions of the Microsoft |
5383 | runtime libraries. This might get you to about \f(CW512\fR or \f(CW2048\fR sockets |
5422 | runtime libraries. This might get you to about \f(CW512\fR or \f(CW2048\fR sockets |
5384 | (depending on windows version and/or the phase of the moon). To get more, |
5423 | (depending on windows version and/or the phase of the moon). To get more, |
5385 | you need to wrap all I/O functions and provide your own fd management, but |
5424 | you need to wrap all I/O functions and provide your own fd management, but |
5386 | the cost of calling select (O(nA\*^X)) will likely make this unworkable. |
5425 | the cost of calling select (O(nX)) will likely make this unworkable. |
5387 | .SS "\s-1PORTABILITY\s0 \s-1REQUIREMENTS\s0" |
5426 | .SS "\s-1PORTABILITY REQUIREMENTS\s0" |
5388 | .IX Subsection "PORTABILITY REQUIREMENTS" |
5427 | .IX Subsection "PORTABILITY REQUIREMENTS" |
5389 | In addition to a working ISO-C implementation and of course the |
5428 | In addition to a working ISO-C implementation and of course the |
5390 | backend-specific APIs, libev relies on a few additional extensions: |
5429 | backend-specific APIs, libev relies on a few additional extensions: |
5391 | .ie n .IP """void (*)(ev_watcher_type *, int revents)"" must have compatible calling conventions regardless of ""ev_watcher_type *""." 4 |
5430 | .ie n .IP """void (*)(ev_watcher_type *, int revents)"" must have compatible calling conventions regardless of ""ev_watcher_type *""." 4 |
5392 | .el .IP "\f(CWvoid (*)(ev_watcher_type *, int revents)\fR must have compatible calling conventions regardless of \f(CWev_watcher_type *\fR." 4 |
5431 | .el .IP "\f(CWvoid (*)(ev_watcher_type *, int revents)\fR must have compatible calling conventions regardless of \f(CWev_watcher_type *\fR." 4 |
5393 | .IX Item "void (*)(ev_watcher_type *, int revents) must have compatible calling conventions regardless of ev_watcher_type *." |
5432 | .IX Item "void (*)(ev_watcher_type *, int revents) must have compatible calling conventions regardless of ev_watcher_type *." |
5394 | Libev assumes not only that all watcher pointers have the same internal |
5433 | Libev assumes not only that all watcher pointers have the same internal |
5395 | structure (guaranteed by \s-1POSIX\s0 but not by \s-1ISO\s0 C for example), but it also |
5434 | structure (guaranteed by \s-1POSIX\s0 but not by \s-1ISO C\s0 for example), but it also |
5396 | assumes that the same (machine) code can be used to call any watcher |
5435 | assumes that the same (machine) code can be used to call any watcher |
5397 | callback: The watcher callbacks have different type signatures, but libev |
5436 | callback: The watcher callbacks have different type signatures, but libev |
5398 | calls them using an \f(CW\*(C`ev_watcher *\*(C'\fR internally. |
5437 | calls them using an \f(CW\*(C`ev_watcher *\*(C'\fR internally. |
|
|
5438 | .IP "null pointers and integer zero are represented by 0 bytes" 4 |
|
|
5439 | .IX Item "null pointers and integer zero are represented by 0 bytes" |
|
|
5440 | Libev uses \f(CW\*(C`memset\*(C'\fR to initialise structs and arrays to \f(CW0\fR bytes, and |
|
|
5441 | relies on this setting pointers and integers to null. |
5399 | .IP "pointer accesses must be thread-atomic" 4 |
5442 | .IP "pointer accesses must be thread-atomic" 4 |
5400 | .IX Item "pointer accesses must be thread-atomic" |
5443 | .IX Item "pointer accesses must be thread-atomic" |
5401 | Accessing a pointer value must be atomic, it must both be readable and |
5444 | Accessing a pointer value must be atomic, it must both be readable and |
5402 | writable in one piece \- this is the case on all current architectures. |
5445 | writable in one piece \- this is the case on all current architectures. |
5403 | .ie n .IP """sig_atomic_t volatile"" must be thread-atomic as well" 4 |
5446 | .ie n .IP """sig_atomic_t volatile"" must be thread-atomic as well" 4 |
… | |
… | |
5421 | except the initial one, and run the signal handling loop in the initial |
5464 | except the initial one, and run the signal handling loop in the initial |
5422 | thread as well. |
5465 | thread as well. |
5423 | .ie n .IP """long"" must be large enough for common memory allocation sizes" 4 |
5466 | .ie n .IP """long"" must be large enough for common memory allocation sizes" 4 |
5424 | .el .IP "\f(CWlong\fR must be large enough for common memory allocation sizes" 4 |
5467 | .el .IP "\f(CWlong\fR must be large enough for common memory allocation sizes" 4 |
5425 | .IX Item "long must be large enough for common memory allocation sizes" |
5468 | .IX Item "long must be large enough for common memory allocation sizes" |
5426 | To improve portability and simplify its \s-1API\s0, libev uses \f(CW\*(C`long\*(C'\fR internally |
5469 | To improve portability and simplify its \s-1API,\s0 libev uses \f(CW\*(C`long\*(C'\fR internally |
5427 | instead of \f(CW\*(C`size_t\*(C'\fR when allocating its data structures. On non-POSIX |
5470 | instead of \f(CW\*(C`size_t\*(C'\fR when allocating its data structures. On non-POSIX |
5428 | systems (Microsoft...) this might be unexpectedly low, but is still at |
5471 | systems (Microsoft...) this might be unexpectedly low, but is still at |
5429 | least 31 bits everywhere, which is enough for hundreds of millions of |
5472 | least 31 bits everywhere, which is enough for hundreds of millions of |
5430 | watchers. |
5473 | watchers. |
5431 | .ie n .IP """double"" must hold a time value in seconds with enough accuracy" 4 |
5474 | .ie n .IP """double"" must hold a time value in seconds with enough accuracy" 4 |
… | |
… | |
5433 | .IX Item "double must hold a time value in seconds with enough accuracy" |
5476 | .IX Item "double must hold a time value in seconds with enough accuracy" |
5434 | The type \f(CW\*(C`double\*(C'\fR is used to represent timestamps. It is required to |
5477 | The type \f(CW\*(C`double\*(C'\fR is used to represent timestamps. It is required to |
5435 | have at least 51 bits of mantissa (and 9 bits of exponent), which is |
5478 | have at least 51 bits of mantissa (and 9 bits of exponent), which is |
5436 | good enough for at least into the year 4000 with millisecond accuracy |
5479 | good enough for at least into the year 4000 with millisecond accuracy |
5437 | (the design goal for libev). This requirement is overfulfilled by |
5480 | (the design goal for libev). This requirement is overfulfilled by |
5438 | implementations using \s-1IEEE\s0 754, which is basically all existing ones. |
5481 | implementations using \s-1IEEE 754,\s0 which is basically all existing ones. |
5439 | .Sp |
5482 | .Sp |
5440 | With \s-1IEEE\s0 754 doubles, you get microsecond accuracy until at least the |
5483 | With \s-1IEEE 754\s0 doubles, you get microsecond accuracy until at least the |
5441 | year 2255 (and millisecond accuracy till the year 287396 \- by then, libev |
5484 | year 2255 (and millisecond accuracy till the year 287396 \- by then, libev |
5442 | is either obsolete or somebody patched it to use \f(CW\*(C`long double\*(C'\fR or |
5485 | is either obsolete or somebody patched it to use \f(CW\*(C`long double\*(C'\fR or |
5443 | something like that, just kidding). |
5486 | something like that, just kidding). |
5444 | .PP |
5487 | .PP |
5445 | If you know of other additional requirements drop me a note. |
5488 | If you know of other additional requirements drop me a note. |
… | |
… | |
5507 | calls in the current loop iteration and the loop is currently |
5550 | calls in the current loop iteration and the loop is currently |
5508 | blocked. Checking for async and signal events involves iterating over all |
5551 | blocked. Checking for async and signal events involves iterating over all |
5509 | running async watchers or all signal numbers. |
5552 | running async watchers or all signal numbers. |
5510 | .SH "PORTING FROM LIBEV 3.X TO 4.X" |
5553 | .SH "PORTING FROM LIBEV 3.X TO 4.X" |
5511 | .IX Header "PORTING FROM LIBEV 3.X TO 4.X" |
5554 | .IX Header "PORTING FROM LIBEV 3.X TO 4.X" |
5512 | The major version 4 introduced some incompatible changes to the \s-1API\s0. |
5555 | The major version 4 introduced some incompatible changes to the \s-1API.\s0 |
5513 | .PP |
5556 | .PP |
5514 | At the moment, the \f(CW\*(C`ev.h\*(C'\fR header file provides compatibility definitions |
5557 | At the moment, the \f(CW\*(C`ev.h\*(C'\fR header file provides compatibility definitions |
5515 | for all changes, so most programs should still compile. The compatibility |
5558 | for all changes, so most programs should still compile. The compatibility |
5516 | layer might be removed in later versions of libev, so better update to the |
5559 | layer might be removed in later versions of libev, so better update to the |
5517 | new \s-1API\s0 early than late. |
5560 | new \s-1API\s0 early than late. |
5518 | .ie n .IP """EV_COMPAT3"" backwards compatibility mechanism" 4 |
5561 | .ie n .IP """EV_COMPAT3"" backwards compatibility mechanism" 4 |
5519 | .el .IP "\f(CWEV_COMPAT3\fR backwards compatibility mechanism" 4 |
5562 | .el .IP "\f(CWEV_COMPAT3\fR backwards compatibility mechanism" 4 |
5520 | .IX Item "EV_COMPAT3 backwards compatibility mechanism" |
5563 | .IX Item "EV_COMPAT3 backwards compatibility mechanism" |
5521 | The backward compatibility mechanism can be controlled by |
5564 | The backward compatibility mechanism can be controlled by |
5522 | \&\f(CW\*(C`EV_COMPAT3\*(C'\fR. See \*(L"\s-1PREPROCESSOR\s0 \s-1SYMBOLS/MACROS\s0\*(R" in the \*(L"\s-1EMBEDDING\s0\*(R" |
5565 | \&\f(CW\*(C`EV_COMPAT3\*(C'\fR. See \*(L"\s-1PREPROCESSOR SYMBOLS/MACROS\*(R"\s0 in the \*(L"\s-1EMBEDDING\*(R"\s0 |
5523 | section. |
5566 | section. |
5524 | .ie n .IP """ev_default_destroy"" and ""ev_default_fork"" have been removed" 4 |
5567 | .ie n .IP """ev_default_destroy"" and ""ev_default_fork"" have been removed" 4 |
5525 | .el .IP "\f(CWev_default_destroy\fR and \f(CWev_default_fork\fR have been removed" 4 |
5568 | .el .IP "\f(CWev_default_destroy\fR and \f(CWev_default_fork\fR have been removed" 4 |
5526 | .IX Item "ev_default_destroy and ev_default_fork have been removed" |
5569 | .IX Item "ev_default_destroy and ev_default_fork have been removed" |
5527 | These calls can be replaced easily by their \f(CW\*(C`ev_loop_xxx\*(C'\fR counterparts: |
5570 | These calls can be replaced easily by their \f(CW\*(C`ev_loop_xxx\*(C'\fR counterparts: |
… | |
… | |
5567 | .SH "GLOSSARY" |
5610 | .SH "GLOSSARY" |
5568 | .IX Header "GLOSSARY" |
5611 | .IX Header "GLOSSARY" |
5569 | .IP "active" 4 |
5612 | .IP "active" 4 |
5570 | .IX Item "active" |
5613 | .IX Item "active" |
5571 | A watcher is active as long as it has been started and not yet stopped. |
5614 | A watcher is active as long as it has been started and not yet stopped. |
5572 | See \*(L"\s-1WATCHER\s0 \s-1STATES\s0\*(R" for details. |
5615 | See \*(L"\s-1WATCHER STATES\*(R"\s0 for details. |
5573 | .IP "application" 4 |
5616 | .IP "application" 4 |
5574 | .IX Item "application" |
5617 | .IX Item "application" |
5575 | In this document, an application is whatever is using libev. |
5618 | In this document, an application is whatever is using libev. |
5576 | .IP "backend" 4 |
5619 | .IP "backend" 4 |
5577 | .IX Item "backend" |
5620 | .IX Item "backend" |
… | |
… | |
5604 | The model used to describe how an event loop handles and processes |
5647 | The model used to describe how an event loop handles and processes |
5605 | watchers and events. |
5648 | watchers and events. |
5606 | .IP "pending" 4 |
5649 | .IP "pending" 4 |
5607 | .IX Item "pending" |
5650 | .IX Item "pending" |
5608 | A watcher is pending as soon as the corresponding event has been |
5651 | A watcher is pending as soon as the corresponding event has been |
5609 | detected. See \*(L"\s-1WATCHER\s0 \s-1STATES\s0\*(R" for details. |
5652 | detected. See \*(L"\s-1WATCHER STATES\*(R"\s0 for details. |
5610 | .IP "real time" 4 |
5653 | .IP "real time" 4 |
5611 | .IX Item "real time" |
5654 | .IX Item "real time" |
5612 | The physical time that is observed. It is apparently strictly monotonic :) |
5655 | The physical time that is observed. It is apparently strictly monotonic :) |
5613 | .IP "wall-clock time" 4 |
5656 | .IP "wall-clock time" 4 |
5614 | .IX Item "wall-clock time" |
5657 | .IX Item "wall-clock time" |