… | |
… | |
260 | flags. If that is troubling you, check C<ev_backend ()> afterwards). |
260 | flags. If that is troubling you, check C<ev_backend ()> afterwards). |
261 | |
261 | |
262 | If you don't know what event loop to use, use the one returned from this |
262 | If you don't know what event loop to use, use the one returned from this |
263 | function. |
263 | function. |
264 | |
264 | |
|
|
265 | The default loop is the only loop that can handle C<ev_signal> and |
|
|
266 | C<ev_child> watchers, and to do this, it always registers a handler |
|
|
267 | for C<SIGCHLD>. If this is a problem for your app you can either |
|
|
268 | create a dynamic loop with C<ev_loop_new> that doesn't do that, or you |
|
|
269 | can simply overwrite the C<SIGCHLD> signal handler I<after> calling |
|
|
270 | C<ev_default_init>. |
|
|
271 | |
265 | The flags argument can be used to specify special behaviour or specific |
272 | The flags argument can be used to specify special behaviour or specific |
266 | backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>). |
273 | backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>). |
267 | |
274 | |
268 | The following flags are supported: |
275 | The following flags are supported: |
269 | |
276 | |
… | |
… | |
403 | While this backend scales well, it requires one system call per active |
410 | While this backend scales well, it requires one system call per active |
404 | file descriptor per loop iteration. For small and medium numbers of file |
411 | file descriptor per loop iteration. For small and medium numbers of file |
405 | descriptors a "slow" C<EVBACKEND_SELECT> or C<EVBACKEND_POLL> backend |
412 | descriptors a "slow" C<EVBACKEND_SELECT> or C<EVBACKEND_POLL> backend |
406 | might perform better. |
413 | might perform better. |
407 | |
414 | |
|
|
415 | On the positive side, ignoring the spurious readyness notifications, this |
|
|
416 | backend actually performed to specification in all tests and is fully |
|
|
417 | embeddable, which is a rare feat among the OS-specific backends. |
|
|
418 | |
408 | =item C<EVBACKEND_ALL> |
419 | =item C<EVBACKEND_ALL> |
409 | |
420 | |
410 | Try all backends (even potentially broken ones that wouldn't be tried |
421 | Try all backends (even potentially broken ones that wouldn't be tried |
411 | with C<EVFLAG_AUTO>). Since this is a mask, you can do stuff such as |
422 | with C<EVFLAG_AUTO>). Since this is a mask, you can do stuff such as |
412 | C<EVBACKEND_ALL & ~EVBACKEND_KQUEUE>. |
423 | C<EVBACKEND_ALL & ~EVBACKEND_KQUEUE>. |
… | |
… | |
414 | It is definitely not recommended to use this flag. |
425 | It is definitely not recommended to use this flag. |
415 | |
426 | |
416 | =back |
427 | =back |
417 | |
428 | |
418 | If one or more of these are ored into the flags value, then only these |
429 | If one or more of these are ored into the flags value, then only these |
419 | backends will be tried (in the reverse order as given here). If none are |
430 | backends will be tried (in the reverse order as listed here). If none are |
420 | specified, most compiled-in backend will be tried, usually in reverse |
431 | specified, all backends in C<ev_recommended_backends ()> will be tried. |
421 | order of their flag values :) |
|
|
422 | |
432 | |
423 | The most typical usage is like this: |
433 | The most typical usage is like this: |
424 | |
434 | |
425 | if (!ev_default_loop (0)) |
435 | if (!ev_default_loop (0)) |
426 | fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?"); |
436 | fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?"); |
… | |
… | |
473 | Like C<ev_default_destroy>, but destroys an event loop created by an |
483 | Like C<ev_default_destroy>, but destroys an event loop created by an |
474 | earlier call to C<ev_loop_new>. |
484 | earlier call to C<ev_loop_new>. |
475 | |
485 | |
476 | =item ev_default_fork () |
486 | =item ev_default_fork () |
477 | |
487 | |
|
|
488 | This function sets a flag that causes subsequent C<ev_loop> iterations |
478 | This function reinitialises the kernel state for backends that have |
489 | to reinitialise the kernel state for backends that have one. Despite the |
479 | one. Despite the name, you can call it anytime, but it makes most sense |
490 | name, you can call it anytime, but it makes most sense after forking, in |
480 | after forking, in either the parent or child process (or both, but that |
491 | the child process (or both child and parent, but that again makes little |
481 | again makes little sense). |
492 | sense). You I<must> call it in the child before using any of the libev |
|
|
493 | functions, and it will only take effect at the next C<ev_loop> iteration. |
482 | |
494 | |
483 | You I<must> call this function in the child process after forking if and |
495 | On the other hand, you only need to call this function in the child |
484 | only if you want to use the event library in both processes. If you just |
496 | process if and only if you want to use the event library in the child. If |
485 | fork+exec, you don't have to call it. |
497 | you just fork+exec, you don't have to call it at all. |
486 | |
498 | |
487 | The function itself is quite fast and it's usually not a problem to call |
499 | The function itself is quite fast and it's usually not a problem to call |
488 | it just in case after a fork. To make this easy, the function will fit in |
500 | it just in case after a fork. To make this easy, the function will fit in |
489 | quite nicely into a call to C<pthread_atfork>: |
501 | quite nicely into a call to C<pthread_atfork>: |
490 | |
502 | |
491 | pthread_atfork (0, 0, ev_default_fork); |
503 | pthread_atfork (0, 0, ev_default_fork); |
492 | |
|
|
493 | At the moment, C<EVBACKEND_SELECT> and C<EVBACKEND_POLL> are safe to use |
|
|
494 | without calling this function, so if you force one of those backends you |
|
|
495 | do not need to care. |
|
|
496 | |
504 | |
497 | =item ev_loop_fork (loop) |
505 | =item ev_loop_fork (loop) |
498 | |
506 | |
499 | Like C<ev_default_fork>, but acts on an event loop created by |
507 | Like C<ev_default_fork>, but acts on an event loop created by |
500 | C<ev_loop_new>. Yes, you have to call this on every allocated event loop |
508 | C<ev_loop_new>. Yes, you have to call this on every allocated event loop |
… | |
… | |
605 | returning, ev_unref() after starting, and ev_ref() before stopping it. For |
613 | returning, ev_unref() after starting, and ev_ref() before stopping it. For |
606 | example, libev itself uses this for its internal signal pipe: It is not |
614 | example, libev itself uses this for its internal signal pipe: It is not |
607 | visible to the libev user and should not keep C<ev_loop> from exiting if |
615 | visible to the libev user and should not keep C<ev_loop> from exiting if |
608 | no event watchers registered by it are active. It is also an excellent |
616 | no event watchers registered by it are active. It is also an excellent |
609 | way to do this for generic recurring timers or from within third-party |
617 | way to do this for generic recurring timers or from within third-party |
610 | libraries. Just remember to I<unref after start> and I<ref before stop>. |
618 | libraries. Just remember to I<unref after start> and I<ref before stop> |
|
|
619 | (but only if the watcher wasn't active before, or was active before, |
|
|
620 | respectively). |
611 | |
621 | |
612 | Example: Create a signal watcher, but keep it from keeping C<ev_loop> |
622 | Example: Create a signal watcher, but keep it from keeping C<ev_loop> |
613 | running when nothing else is active. |
623 | running when nothing else is active. |
614 | |
624 | |
615 | struct ev_signal exitsig; |
625 | struct ev_signal exitsig; |
… | |
… | |
1428 | |
1438 | |
1429 | =head3 Watcher-Specific Functions and Data Members |
1439 | =head3 Watcher-Specific Functions and Data Members |
1430 | |
1440 | |
1431 | =over 4 |
1441 | =over 4 |
1432 | |
1442 | |
1433 | =item ev_child_init (ev_child *, callback, int pid) |
1443 | =item ev_child_init (ev_child *, callback, int pid, int trace) |
1434 | |
1444 | |
1435 | =item ev_child_set (ev_child *, int pid) |
1445 | =item ev_child_set (ev_child *, int pid, int trace) |
1436 | |
1446 | |
1437 | Configures the watcher to wait for status changes of process C<pid> (or |
1447 | Configures the watcher to wait for status changes of process C<pid> (or |
1438 | I<any> process if C<pid> is specified as C<0>). The callback can look |
1448 | I<any> process if C<pid> is specified as C<0>). The callback can look |
1439 | at the C<rstatus> member of the C<ev_child> watcher structure to see |
1449 | at the C<rstatus> member of the C<ev_child> watcher structure to see |
1440 | the status word (use the macros from C<sys/wait.h> and see your systems |
1450 | the status word (use the macros from C<sys/wait.h> and see your systems |
1441 | C<waitpid> documentation). The C<rpid> member contains the pid of the |
1451 | C<waitpid> documentation). The C<rpid> member contains the pid of the |
1442 | process causing the status change. |
1452 | process causing the status change. C<trace> must be either C<0> (only |
|
|
1453 | activate the watcher when the process terminates) or C<1> (additionally |
|
|
1454 | activate the watcher when the process is stopped or continued). |
1443 | |
1455 | |
1444 | =item int pid [read-only] |
1456 | =item int pid [read-only] |
1445 | |
1457 | |
1446 | The process id this watcher watches out for, or C<0>, meaning any process id. |
1458 | The process id this watcher watches out for, or C<0>, meaning any process id. |
1447 | |
1459 | |
… | |
… | |
1683 | static void |
1695 | static void |
1684 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1696 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1685 | { |
1697 | { |
1686 | free (w); |
1698 | free (w); |
1687 | // now do something you wanted to do when the program has |
1699 | // now do something you wanted to do when the program has |
1688 | // no longer asnything immediate to do. |
1700 | // no longer anything immediate to do. |
1689 | } |
1701 | } |
1690 | |
1702 | |
1691 | struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1703 | struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1692 | ev_idle_init (idle_watcher, idle_cb); |
1704 | ev_idle_init (idle_watcher, idle_cb); |
1693 | ev_idle_start (loop, idle_cb); |
1705 | ev_idle_start (loop, idle_cb); |
… | |
… | |
2270 | Example: Define a class with an IO and idle watcher, start one of them in |
2282 | Example: Define a class with an IO and idle watcher, start one of them in |
2271 | the constructor. |
2283 | the constructor. |
2272 | |
2284 | |
2273 | class myclass |
2285 | class myclass |
2274 | { |
2286 | { |
2275 | ev_io io; void io_cb (ev::io &w, int revents); |
2287 | ev::io io; void io_cb (ev::io &w, int revents); |
2276 | ev_idle idle void idle_cb (ev::idle &w, int revents); |
2288 | ev:idle idle void idle_cb (ev::idle &w, int revents); |
2277 | |
2289 | |
2278 | myclass (); |
2290 | myclass (int fd) |
2279 | } |
|
|
2280 | |
|
|
2281 | myclass::myclass (int fd) |
|
|
2282 | { |
2291 | { |
2283 | io .set <myclass, &myclass::io_cb > (this); |
2292 | io .set <myclass, &myclass::io_cb > (this); |
2284 | idle.set <myclass, &myclass::idle_cb> (this); |
2293 | idle.set <myclass, &myclass::idle_cb> (this); |
2285 | |
2294 | |
2286 | io.start (fd, ev::READ); |
2295 | io.start (fd, ev::READ); |
|
|
2296 | } |
2287 | } |
2297 | }; |
2288 | |
2298 | |
2289 | |
2299 | |
2290 | =head1 MACRO MAGIC |
2300 | =head1 MACRO MAGIC |
2291 | |
2301 | |
2292 | Libev can be compiled with a variety of options, the most fundamantal |
2302 | Libev can be compiled with a variety of options, the most fundamantal |
… | |
… | |
2551 | be detected at runtime. |
2561 | be detected at runtime. |
2552 | |
2562 | |
2553 | =item EV_H |
2563 | =item EV_H |
2554 | |
2564 | |
2555 | The name of the F<ev.h> header file used to include it. The default if |
2565 | The name of the F<ev.h> header file used to include it. The default if |
2556 | undefined is C<"ev.h"> in F<event.h> and F<ev.c>. This can be used to |
2566 | undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be |
2557 | virtually rename the F<ev.h> header file in case of conflicts. |
2567 | used to virtually rename the F<ev.h> header file in case of conflicts. |
2558 | |
2568 | |
2559 | =item EV_CONFIG_H |
2569 | =item EV_CONFIG_H |
2560 | |
2570 | |
2561 | If C<EV_STANDALONE> isn't C<1>, this variable can be used to override |
2571 | If C<EV_STANDALONE> isn't C<1>, this variable can be used to override |
2562 | F<ev.c>'s idea of where to find the F<config.h> file, similarly to |
2572 | F<ev.c>'s idea of where to find the F<config.h> file, similarly to |
2563 | C<EV_H>, above. |
2573 | C<EV_H>, above. |
2564 | |
2574 | |
2565 | =item EV_EVENT_H |
2575 | =item EV_EVENT_H |
2566 | |
2576 | |
2567 | Similarly to C<EV_H>, this macro can be used to override F<event.c>'s idea |
2577 | Similarly to C<EV_H>, this macro can be used to override F<event.c>'s idea |
2568 | of how the F<event.h> header can be found, the dfeault is C<"event.h">. |
2578 | of how the F<event.h> header can be found, the default is C<"event.h">. |
2569 | |
2579 | |
2570 | =item EV_PROTOTYPES |
2580 | =item EV_PROTOTYPES |
2571 | |
2581 | |
2572 | If defined to be C<0>, then F<ev.h> will not define any function |
2582 | If defined to be C<0>, then F<ev.h> will not define any function |
2573 | prototypes, but still define all the structs and other symbols. This is |
2583 | prototypes, but still define all the structs and other symbols. This is |