… | |
… | |
105 | details of the event, and then hand it over to libev by I<starting> the |
105 | details of the event, and then hand it over to libev by I<starting> the |
106 | watcher. |
106 | watcher. |
107 | |
107 | |
108 | =head2 FEATURES |
108 | =head2 FEATURES |
109 | |
109 | |
110 | Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the |
110 | Libev supports C<select>, C<poll>, the Linux-specific aio and C<epoll> |
111 | BSD-specific C<kqueue> and the Solaris-specific event port mechanisms |
111 | interfaces, the BSD-specific C<kqueue> and the Solaris-specific event port |
112 | for file descriptor events (C<ev_io>), the Linux C<inotify> interface |
112 | mechanisms for file descriptor events (C<ev_io>), the Linux C<inotify> |
113 | (for C<ev_stat>), Linux eventfd/signalfd (for faster and cleaner |
113 | interface (for C<ev_stat>), Linux eventfd/signalfd (for faster and cleaner |
114 | inter-thread wakeup (C<ev_async>)/signal handling (C<ev_signal>)) relative |
114 | inter-thread wakeup (C<ev_async>)/signal handling (C<ev_signal>)) relative |
115 | timers (C<ev_timer>), absolute timers with customised rescheduling |
115 | timers (C<ev_timer>), absolute timers with customised rescheduling |
116 | (C<ev_periodic>), synchronous signals (C<ev_signal>), process status |
116 | (C<ev_periodic>), synchronous signals (C<ev_signal>), process status |
117 | change events (C<ev_child>), and event watchers dealing with the event |
117 | change events (C<ev_child>), and event watchers dealing with the event |
118 | loop mechanism itself (C<ev_idle>, C<ev_embed>, C<ev_prepare> and |
118 | loop mechanism itself (C<ev_idle>, C<ev_embed>, C<ev_prepare> and |
… | |
… | |
159 | When libev detects a usage error such as a negative timer interval, then |
159 | When libev detects a usage error such as a negative timer interval, then |
160 | it will print a diagnostic message and abort (via the C<assert> mechanism, |
160 | it will print a diagnostic message and abort (via the C<assert> mechanism, |
161 | so C<NDEBUG> will disable this checking): these are programming errors in |
161 | so C<NDEBUG> will disable this checking): these are programming errors in |
162 | the libev caller and need to be fixed there. |
162 | the libev caller and need to be fixed there. |
163 | |
163 | |
|
|
164 | Via the C<EV_FREQUENT> macro you can compile in and/or enable extensive |
|
|
165 | consistency checking code inside libev that can be used to check for |
|
|
166 | internal inconsistencies, suually caused by application bugs. |
|
|
167 | |
164 | Libev also has a few internal error-checking C<assert>ions, and also has |
168 | Libev also has a few internal error-checking C<assert>ions. These do not |
165 | extensive consistency checking code. These do not trigger under normal |
|
|
166 | circumstances, as they indicate either a bug in libev or worse. |
169 | trigger under normal circumstances, as they indicate either a bug in libev |
|
|
170 | or worse. |
167 | |
171 | |
168 | |
172 | |
169 | =head1 GLOBAL FUNCTIONS |
173 | =head1 GLOBAL FUNCTIONS |
170 | |
174 | |
171 | These functions can be called anytime, even before initialising the |
175 | These functions can be called anytime, even before initialising the |
… | |
… | |
265 | |
269 | |
266 | You could override this function in high-availability programs to, say, |
270 | You could override this function in high-availability programs to, say, |
267 | free some memory if it cannot allocate memory, to use a special allocator, |
271 | free some memory if it cannot allocate memory, to use a special allocator, |
268 | or even to sleep a while and retry until some memory is available. |
272 | or even to sleep a while and retry until some memory is available. |
269 | |
273 | |
|
|
274 | Example: The following is the C<realloc> function that libev itself uses |
|
|
275 | which should work with C<realloc> and C<free> functions of all kinds and |
|
|
276 | is probably a good basis for your own implementation. |
|
|
277 | |
|
|
278 | static void * |
|
|
279 | ev_realloc_emul (void *ptr, long size) EV_NOEXCEPT |
|
|
280 | { |
|
|
281 | if (size) |
|
|
282 | return realloc (ptr, size); |
|
|
283 | |
|
|
284 | free (ptr); |
|
|
285 | return 0; |
|
|
286 | } |
|
|
287 | |
270 | Example: Replace the libev allocator with one that waits a bit and then |
288 | Example: Replace the libev allocator with one that waits a bit and then |
271 | retries (example requires a standards-compliant C<realloc>). |
289 | retries. |
272 | |
290 | |
273 | static void * |
291 | static void * |
274 | persistent_realloc (void *ptr, size_t size) |
292 | persistent_realloc (void *ptr, size_t size) |
275 | { |
293 | { |
|
|
294 | if (!size) |
|
|
295 | { |
|
|
296 | free (ptr); |
|
|
297 | return 0; |
|
|
298 | } |
|
|
299 | |
276 | for (;;) |
300 | for (;;) |
277 | { |
301 | { |
278 | void *newptr = realloc (ptr, size); |
302 | void *newptr = realloc (ptr, size); |
279 | |
303 | |
280 | if (newptr) |
304 | if (newptr) |
… | |
… | |
491 | This backend maps C<EV_READ> to C<POLLIN | POLLERR | POLLHUP>, and |
515 | This backend maps C<EV_READ> to C<POLLIN | POLLERR | POLLHUP>, and |
492 | C<EV_WRITE> to C<POLLOUT | POLLERR | POLLHUP>. |
516 | C<EV_WRITE> to C<POLLOUT | POLLERR | POLLHUP>. |
493 | |
517 | |
494 | =item C<EVBACKEND_EPOLL> (value 4, Linux) |
518 | =item C<EVBACKEND_EPOLL> (value 4, Linux) |
495 | |
519 | |
496 | Use the linux-specific epoll(7) interface (for both pre- and post-2.6.9 |
520 | Use the Linux-specific epoll(7) interface (for both pre- and post-2.6.9 |
497 | kernels). |
521 | kernels). |
498 | |
522 | |
499 | For few fds, this backend is a bit little slower than poll and select, but |
523 | For few fds, this backend is a bit little slower than poll and select, but |
500 | it scales phenomenally better. While poll and select usually scale like |
524 | it scales phenomenally better. While poll and select usually scale like |
501 | O(total_fds) where total_fds is the total number of fds (or the highest |
525 | O(total_fds) where total_fds is the total number of fds (or the highest |
… | |
… | |
547 | All this means that, in practice, C<EVBACKEND_SELECT> can be as fast or |
571 | All this means that, in practice, C<EVBACKEND_SELECT> can be as fast or |
548 | faster than epoll for maybe up to a hundred file descriptors, depending on |
572 | faster than epoll for maybe up to a hundred file descriptors, depending on |
549 | the usage. So sad. |
573 | the usage. So sad. |
550 | |
574 | |
551 | While nominally embeddable in other event loops, this feature is broken in |
575 | While nominally embeddable in other event loops, this feature is broken in |
552 | all kernel versions tested so far. |
576 | a lot of kernel revisions, but probably(!) works in current versions. |
553 | |
577 | |
554 | This backend maps C<EV_READ> and C<EV_WRITE> in the same way as |
578 | This backend maps C<EV_READ> and C<EV_WRITE> in the same way as |
555 | C<EVBACKEND_POLL>. |
579 | C<EVBACKEND_POLL>. |
556 | |
580 | |
|
|
581 | =item C<EVBACKEND_LINUXAIO> (value 64, Linux) |
|
|
582 | |
|
|
583 | Use the Linux-specific Linux AIO (I<not> C<< aio(7) >> but C<< |
|
|
584 | io_submit(2) >>) event interface available in post-4.18 kernels (but libev |
|
|
585 | only tries to use it in 4.19+). |
|
|
586 | |
|
|
587 | This is another Linux train wreck of an event interface. |
|
|
588 | |
|
|
589 | If this backend works for you (as of this writing, it was very |
|
|
590 | experimental), it is the best event interface available on Linux and might |
|
|
591 | be well worth enabling it - if it isn't available in your kernel this will |
|
|
592 | be detected and this backend will be skipped. |
|
|
593 | |
|
|
594 | This backend can batch oneshot requests and supports a user-space ring |
|
|
595 | buffer to receive events. It also doesn't suffer from most of the design |
|
|
596 | problems of epoll (such as not being able to remove event sources from |
|
|
597 | the epoll set), and generally sounds too good to be true. Because, this |
|
|
598 | being the Linux kernel, of course it suffers from a whole new set of |
|
|
599 | limitations, forcing you to fall back to epoll, inheriting all its design |
|
|
600 | issues. |
|
|
601 | |
|
|
602 | For one, it is not easily embeddable (but probably could be done using |
|
|
603 | an event fd at some extra overhead). It also is subject to a system wide |
|
|
604 | limit that can be configured in F</proc/sys/fs/aio-max-nr>. If no AIO |
|
|
605 | requests are left, this backend will be skipped during initialisation, and |
|
|
606 | will switch to epoll when the loop is active. |
|
|
607 | |
|
|
608 | Most problematic in practice, however, is that not all file descriptors |
|
|
609 | work with it. For example, in Linux 5.1, TCP sockets, pipes, event fds, |
|
|
610 | files, F</dev/null> and many others are supported, but ttys do not work |
|
|
611 | properly (a known bug that the kernel developers don't care about, see |
|
|
612 | L<https://lore.kernel.org/patchwork/patch/1047453/>), so this is not |
|
|
613 | (yet?) a generic event polling interface. |
|
|
614 | |
|
|
615 | Overall, it seems the Linux developers just don't want it to have a |
|
|
616 | generic event handling mechanism other than C<select> or C<poll>. |
|
|
617 | |
|
|
618 | To work around all these problem, the current version of libev uses its |
|
|
619 | epoll backend as a fallback for file descriptor types that do not work. Or |
|
|
620 | falls back completely to epoll if the kernel acts up. |
|
|
621 | |
|
|
622 | This backend maps C<EV_READ> and C<EV_WRITE> in the same way as |
|
|
623 | C<EVBACKEND_POLL>. |
|
|
624 | |
557 | =item C<EVBACKEND_KQUEUE> (value 8, most BSD clones) |
625 | =item C<EVBACKEND_KQUEUE> (value 8, most BSD clones) |
558 | |
626 | |
559 | Kqueue deserves special mention, as at the time of this writing, it |
627 | Kqueue deserves special mention, as at the time this backend was |
560 | was broken on all BSDs except NetBSD (usually it doesn't work reliably |
628 | implemented, it was broken on all BSDs except NetBSD (usually it doesn't |
561 | with anything but sockets and pipes, except on Darwin, where of course |
629 | work reliably with anything but sockets and pipes, except on Darwin, |
562 | it's completely useless). Unlike epoll, however, whose brokenness |
630 | where of course it's completely useless). Unlike epoll, however, whose |
563 | is by design, these kqueue bugs can (and eventually will) be fixed |
631 | brokenness is by design, these kqueue bugs can be (and mostly have been) |
564 | without API changes to existing programs. For this reason it's not being |
632 | fixed without API changes to existing programs. For this reason it's not |
565 | "auto-detected" unless you explicitly specify it in the flags (i.e. using |
633 | being "auto-detected" on all platforms unless you explicitly specify it |
566 | C<EVBACKEND_KQUEUE>) or libev was compiled on a known-to-be-good (-enough) |
634 | in the flags (i.e. using C<EVBACKEND_KQUEUE>) or libev was compiled on a |
567 | system like NetBSD. |
635 | known-to-be-good (-enough) system like NetBSD. |
568 | |
636 | |
569 | You still can embed kqueue into a normal poll or select backend and use it |
637 | You still can embed kqueue into a normal poll or select backend and use it |
570 | only for sockets (after having made sure that sockets work with kqueue on |
638 | only for sockets (after having made sure that sockets work with kqueue on |
571 | the target platform). See C<ev_embed> watchers for more info. |
639 | the target platform). See C<ev_embed> watchers for more info. |
572 | |
640 | |
573 | It scales in the same way as the epoll backend, but the interface to the |
641 | It scales in the same way as the epoll backend, but the interface to the |
574 | kernel is more efficient (which says nothing about its actual speed, of |
642 | kernel is more efficient (which says nothing about its actual speed, of |
575 | course). While stopping, setting and starting an I/O watcher does never |
643 | course). While stopping, setting and starting an I/O watcher does never |
576 | cause an extra system call as with C<EVBACKEND_EPOLL>, it still adds up to |
644 | cause an extra system call as with C<EVBACKEND_EPOLL>, it still adds up to |
577 | two event changes per incident. Support for C<fork ()> is very bad (you |
645 | two event changes per incident. Support for C<fork ()> is very bad (you |
578 | might have to leak fd's on fork, but it's more sane than epoll) and it |
646 | might have to leak fds on fork, but it's more sane than epoll) and it |
579 | drops fds silently in similarly hard-to-detect cases. |
647 | drops fds silently in similarly hard-to-detect cases. |
580 | |
648 | |
581 | This backend usually performs well under most conditions. |
649 | This backend usually performs well under most conditions. |
582 | |
650 | |
583 | While nominally embeddable in other event loops, this doesn't work |
651 | While nominally embeddable in other event loops, this doesn't work |
… | |
… | |
657 | |
725 | |
658 | Example: Use whatever libev has to offer, but make sure that kqueue is |
726 | Example: Use whatever libev has to offer, but make sure that kqueue is |
659 | used if available. |
727 | used if available. |
660 | |
728 | |
661 | struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_KQUEUE); |
729 | struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_KQUEUE); |
|
|
730 | |
|
|
731 | Example: Similarly, on linux, you mgiht want to take advantage of the |
|
|
732 | linux aio backend if possible, but fall back to something else if that |
|
|
733 | isn't available. |
|
|
734 | |
|
|
735 | struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_LINUXAIO); |
662 | |
736 | |
663 | =item ev_loop_destroy (loop) |
737 | =item ev_loop_destroy (loop) |
664 | |
738 | |
665 | Destroys an event loop object (frees all memory and kernel state |
739 | Destroys an event loop object (frees all memory and kernel state |
666 | etc.). None of the active event watchers will be stopped in the normal |
740 | etc.). None of the active event watchers will be stopped in the normal |
… | |
… | |
1610 | |
1684 | |
1611 | But really, best use non-blocking mode. |
1685 | But really, best use non-blocking mode. |
1612 | |
1686 | |
1613 | =head3 The special problem of disappearing file descriptors |
1687 | =head3 The special problem of disappearing file descriptors |
1614 | |
1688 | |
1615 | Some backends (e.g. kqueue, epoll) need to be told about closing a file |
1689 | Some backends (e.g. kqueue, epoll, linuxaio) need to be told about closing |
1616 | descriptor (either due to calling C<close> explicitly or any other means, |
1690 | a file descriptor (either due to calling C<close> explicitly or any other |
1617 | such as C<dup2>). The reason is that you register interest in some file |
1691 | means, such as C<dup2>). The reason is that you register interest in some |
1618 | descriptor, but when it goes away, the operating system will silently drop |
1692 | file descriptor, but when it goes away, the operating system will silently |
1619 | this interest. If another file descriptor with the same number then is |
1693 | drop this interest. If another file descriptor with the same number then |
1620 | registered with libev, there is no efficient way to see that this is, in |
1694 | is registered with libev, there is no efficient way to see that this is, |
1621 | fact, a different file descriptor. |
1695 | in fact, a different file descriptor. |
1622 | |
1696 | |
1623 | To avoid having to explicitly tell libev about such cases, libev follows |
1697 | To avoid having to explicitly tell libev about such cases, libev follows |
1624 | the following policy: Each time C<ev_io_set> is being called, libev |
1698 | the following policy: Each time C<ev_io_set> is being called, libev |
1625 | will assume that this is potentially a new file descriptor, otherwise |
1699 | will assume that this is potentially a new file descriptor, otherwise |
1626 | it is assumed that the file descriptor stays the same. That means that |
1700 | it is assumed that the file descriptor stays the same. That means that |
… | |
… | |
1675 | when you rarely read from a file instead of from a socket, and want to |
1749 | when you rarely read from a file instead of from a socket, and want to |
1676 | reuse the same code path. |
1750 | reuse the same code path. |
1677 | |
1751 | |
1678 | =head3 The special problem of fork |
1752 | =head3 The special problem of fork |
1679 | |
1753 | |
1680 | Some backends (epoll, kqueue) do not support C<fork ()> at all or exhibit |
1754 | Some backends (epoll, kqueue, linuxaio, iouring) do not support C<fork ()> |
1681 | useless behaviour. Libev fully supports fork, but needs to be told about |
1755 | at all or exhibit useless behaviour. Libev fully supports fork, but needs |
1682 | it in the child if you want to continue to use it in the child. |
1756 | to be told about it in the child if you want to continue to use it in the |
|
|
1757 | child. |
1683 | |
1758 | |
1684 | To support fork in your child processes, you have to call C<ev_loop_fork |
1759 | To support fork in your child processes, you have to call C<ev_loop_fork |
1685 | ()> after a fork in the child, enable C<EVFLAG_FORKCHECK>, or resort to |
1760 | ()> after a fork in the child, enable C<EVFLAG_FORKCHECK>, or resort to |
1686 | C<EVBACKEND_SELECT> or C<EVBACKEND_POLL>. |
1761 | C<EVBACKEND_SELECT> or C<EVBACKEND_POLL>. |
1687 | |
1762 | |
… | |
… | |
2114 | |
2189 | |
2115 | =item ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat) |
2190 | =item ev_timer_init (ev_timer *, callback, ev_tstamp after, ev_tstamp repeat) |
2116 | |
2191 | |
2117 | =item ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat) |
2192 | =item ev_timer_set (ev_timer *, ev_tstamp after, ev_tstamp repeat) |
2118 | |
2193 | |
2119 | Configure the timer to trigger after C<after> seconds. If C<repeat> |
2194 | Configure the timer to trigger after C<after> seconds (fractional and |
2120 | is C<0.>, then it will automatically be stopped once the timeout is |
2195 | negative values are supported). If C<repeat> is C<0.>, then it will |
2121 | reached. If it is positive, then the timer will automatically be |
2196 | automatically be stopped once the timeout is reached. If it is positive, |
2122 | configured to trigger again C<repeat> seconds later, again, and again, |
2197 | then the timer will automatically be configured to trigger again C<repeat> |
2123 | until stopped manually. |
2198 | seconds later, again, and again, until stopped manually. |
2124 | |
2199 | |
2125 | The timer itself will do a best-effort at avoiding drift, that is, if |
2200 | The timer itself will do a best-effort at avoiding drift, that is, if |
2126 | you configure a timer to trigger every 10 seconds, then it will normally |
2201 | you configure a timer to trigger every 10 seconds, then it will normally |
2127 | trigger at exactly 10 second intervals. If, however, your program cannot |
2202 | trigger at exactly 10 second intervals. If, however, your program cannot |
2128 | keep up with the timer (because it takes longer than those 10 seconds to |
2203 | keep up with the timer (because it takes longer than those 10 seconds to |
… | |
… | |
2225 | C<ev_timer>, which would still trigger roughly 10 seconds after starting |
2300 | C<ev_timer>, which would still trigger roughly 10 seconds after starting |
2226 | it, as it uses a relative timeout). |
2301 | it, as it uses a relative timeout). |
2227 | |
2302 | |
2228 | C<ev_periodic> watchers can also be used to implement vastly more complex |
2303 | C<ev_periodic> watchers can also be used to implement vastly more complex |
2229 | timers, such as triggering an event on each "midnight, local time", or |
2304 | timers, such as triggering an event on each "midnight, local time", or |
2230 | other complicated rules. This cannot be done with C<ev_timer> watchers, as |
2305 | other complicated rules. This cannot easily be done with C<ev_timer> |
2231 | those cannot react to time jumps. |
2306 | watchers, as those cannot react to time jumps. |
2232 | |
2307 | |
2233 | As with timers, the callback is guaranteed to be invoked only when the |
2308 | As with timers, the callback is guaranteed to be invoked only when the |
2234 | point in time where it is supposed to trigger has passed. If multiple |
2309 | point in time where it is supposed to trigger has passed. If multiple |
2235 | timers become ready during the same loop iteration then the ones with |
2310 | timers become ready during the same loop iteration then the ones with |
2236 | earlier time-out values are invoked before ones with later time-out values |
2311 | earlier time-out values are invoked before ones with later time-out values |
… | |
… | |
2322 | |
2397 | |
2323 | NOTE: I<< This callback must always return a time that is higher than or |
2398 | NOTE: I<< This callback must always return a time that is higher than or |
2324 | equal to the passed C<now> value >>. |
2399 | equal to the passed C<now> value >>. |
2325 | |
2400 | |
2326 | This can be used to create very complex timers, such as a timer that |
2401 | This can be used to create very complex timers, such as a timer that |
2327 | triggers on "next midnight, local time". To do this, you would calculate the |
2402 | triggers on "next midnight, local time". To do this, you would calculate |
2328 | next midnight after C<now> and return the timestamp value for this. How |
2403 | the next midnight after C<now> and return the timestamp value for |
2329 | you do this is, again, up to you (but it is not trivial, which is the main |
2404 | this. Here is a (completely untested, no error checking) example on how to |
2330 | reason I omitted it as an example). |
2405 | do this: |
|
|
2406 | |
|
|
2407 | #include <time.h> |
|
|
2408 | |
|
|
2409 | static ev_tstamp |
|
|
2410 | my_rescheduler (ev_periodic *w, ev_tstamp now) |
|
|
2411 | { |
|
|
2412 | time_t tnow = (time_t)now; |
|
|
2413 | struct tm tm; |
|
|
2414 | localtime_r (&tnow, &tm); |
|
|
2415 | |
|
|
2416 | tm.tm_sec = tm.tm_min = tm.tm_hour = 0; // midnight current day |
|
|
2417 | ++tm.tm_mday; // midnight next day |
|
|
2418 | |
|
|
2419 | return mktime (&tm); |
|
|
2420 | } |
|
|
2421 | |
|
|
2422 | Note: this code might run into trouble on days that have more then two |
|
|
2423 | midnights (beginning and end). |
2331 | |
2424 | |
2332 | =back |
2425 | =back |
2333 | |
2426 | |
2334 | =item ev_periodic_again (loop, ev_periodic *) |
2427 | =item ev_periodic_again (loop, ev_periodic *) |
2335 | |
2428 | |
… | |
… | |
3518 | |
3611 | |
3519 | There are some other functions of possible interest. Described. Here. Now. |
3612 | There are some other functions of possible interest. Described. Here. Now. |
3520 | |
3613 | |
3521 | =over 4 |
3614 | =over 4 |
3522 | |
3615 | |
3523 | =item ev_once (loop, int fd, int events, ev_tstamp timeout, callback) |
3616 | =item ev_once (loop, int fd, int events, ev_tstamp timeout, callback, arg) |
3524 | |
3617 | |
3525 | This function combines a simple timer and an I/O watcher, calls your |
3618 | This function combines a simple timer and an I/O watcher, calls your |
3526 | callback on whichever event happens first and automatically stops both |
3619 | callback on whichever event happens first and automatically stops both |
3527 | watchers. This is useful if you want to wait for a single event on an fd |
3620 | watchers. This is useful if you want to wait for a single event on an fd |
3528 | or timeout without having to allocate/configure/start/stop/free one or |
3621 | or timeout without having to allocate/configure/start/stop/free one or |
… | |
… | |
3960 | The normal C API should work fine when used from C++: both ev.h and the |
4053 | The normal C API should work fine when used from C++: both ev.h and the |
3961 | libev sources can be compiled as C++. Therefore, code that uses the C API |
4054 | libev sources can be compiled as C++. Therefore, code that uses the C API |
3962 | will work fine. |
4055 | will work fine. |
3963 | |
4056 | |
3964 | Proper exception specifications might have to be added to callbacks passed |
4057 | Proper exception specifications might have to be added to callbacks passed |
3965 | to libev: exceptions may be thrown only from watcher callbacks, all |
4058 | to libev: exceptions may be thrown only from watcher callbacks, all other |
3966 | other callbacks (allocator, syserr, loop acquire/release and periodic |
4059 | callbacks (allocator, syserr, loop acquire/release and periodic reschedule |
3967 | reschedule callbacks) must not throw exceptions, and might need a C<throw |
4060 | callbacks) must not throw exceptions, and might need a C<noexcept> |
3968 | ()> specification. If you have code that needs to be compiled as both C |
4061 | specification. If you have code that needs to be compiled as both C and |
3969 | and C++ you can use the C<EV_THROW> macro for this: |
4062 | C++ you can use the C<EV_NOEXCEPT> macro for this: |
3970 | |
4063 | |
3971 | static void |
4064 | static void |
3972 | fatal_error (const char *msg) EV_THROW |
4065 | fatal_error (const char *msg) EV_NOEXCEPT |
3973 | { |
4066 | { |
3974 | perror (msg); |
4067 | perror (msg); |
3975 | abort (); |
4068 | abort (); |
3976 | } |
4069 | } |
3977 | |
4070 | |
… | |
… | |
4390 | ev_win32.c required on win32 platforms only |
4483 | ev_win32.c required on win32 platforms only |
4391 | |
4484 | |
4392 | ev_select.c only when select backend is enabled |
4485 | ev_select.c only when select backend is enabled |
4393 | ev_poll.c only when poll backend is enabled |
4486 | ev_poll.c only when poll backend is enabled |
4394 | ev_epoll.c only when the epoll backend is enabled |
4487 | ev_epoll.c only when the epoll backend is enabled |
|
|
4488 | ev_linuxaio.c only when the linux aio backend is enabled |
|
|
4489 | ev_iouring.c only when the linux io_uring backend is enabled |
4395 | ev_kqueue.c only when the kqueue backend is enabled |
4490 | ev_kqueue.c only when the kqueue backend is enabled |
4396 | ev_port.c only when the solaris port backend is enabled |
4491 | ev_port.c only when the solaris port backend is enabled |
4397 | |
4492 | |
4398 | F<ev.c> includes the backend files directly when enabled, so you only need |
4493 | F<ev.c> includes the backend files directly when enabled, so you only need |
4399 | to compile this single file. |
4494 | to compile this single file. |
… | |
… | |
4589 | If defined to be C<1>, libev will compile in support for the Linux |
4684 | If defined to be C<1>, libev will compile in support for the Linux |
4590 | C<epoll>(7) backend. Its availability will be detected at runtime, |
4685 | C<epoll>(7) backend. Its availability will be detected at runtime, |
4591 | otherwise another method will be used as fallback. This is the preferred |
4686 | otherwise another method will be used as fallback. This is the preferred |
4592 | backend for GNU/Linux systems. If undefined, it will be enabled if the |
4687 | backend for GNU/Linux systems. If undefined, it will be enabled if the |
4593 | headers indicate GNU/Linux + Glibc 2.4 or newer, otherwise disabled. |
4688 | headers indicate GNU/Linux + Glibc 2.4 or newer, otherwise disabled. |
|
|
4689 | |
|
|
4690 | =item EV_USE_LINUXAIO |
|
|
4691 | |
|
|
4692 | If defined to be C<1>, libev will compile in support for the Linux aio |
|
|
4693 | backend (C<EV_USE_EPOLL> must also be enabled). If undefined, it will be |
|
|
4694 | enabled on linux, otherwise disabled. |
|
|
4695 | |
|
|
4696 | =item EV_USE_IOURING |
|
|
4697 | |
|
|
4698 | If defined to be C<1>, libev will compile in support for the Linux |
|
|
4699 | io_uring backend (C<EV_USE_EPOLL> must also be enabled). Due to it's |
|
|
4700 | current limitations it has to be requested explicitly. If undefined, it |
|
|
4701 | will be enabled on linux, otherwise disabled. |
4594 | |
4702 | |
4595 | =item EV_USE_KQUEUE |
4703 | =item EV_USE_KQUEUE |
4596 | |
4704 | |
4597 | If defined to be C<1>, libev will compile in support for the BSD style |
4705 | If defined to be C<1>, libev will compile in support for the BSD style |
4598 | C<kqueue>(2) backend. Its actual availability will be detected at runtime, |
4706 | C<kqueue>(2) backend. Its actual availability will be detected at runtime, |
… | |
… | |
4876 | called. If set to C<2>, then the internal verification code will be |
4984 | called. If set to C<2>, then the internal verification code will be |
4877 | called once per loop, which can slow down libev. If set to C<3>, then the |
4985 | called once per loop, which can slow down libev. If set to C<3>, then the |
4878 | verification code will be called very frequently, which will slow down |
4986 | verification code will be called very frequently, which will slow down |
4879 | libev considerably. |
4987 | libev considerably. |
4880 | |
4988 | |
|
|
4989 | Verification errors are reported via C's C<assert> mechanism, so if you |
|
|
4990 | disable that (e.g. by defining C<NDEBUG>) then no errors will be reported. |
|
|
4991 | |
4881 | The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it |
4992 | The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it |
4882 | will be C<0>. |
4993 | will be C<0>. |
4883 | |
4994 | |
4884 | =item EV_COMMON |
4995 | =item EV_COMMON |
4885 | |
4996 | |