… | |
… | |
483 | 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 |
484 | earlier call to C<ev_loop_new>. |
484 | earlier call to C<ev_loop_new>. |
485 | |
485 | |
486 | =item ev_default_fork () |
486 | =item ev_default_fork () |
487 | |
487 | |
|
|
488 | This function sets a flag that causes subsequent C<ev_loop> iterations |
488 | This function reinitialises the kernel state for backends that have |
489 | to reinitialise the kernel state for backends that have one. Despite the |
489 | 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 |
490 | 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 |
491 | 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. |
492 | |
494 | |
493 | 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 |
494 | 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 |
495 | fork+exec, you don't have to call it. |
497 | you just fork+exec, you don't have to call it at all. |
496 | |
498 | |
497 | 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 |
498 | 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 |
499 | quite nicely into a call to C<pthread_atfork>: |
501 | quite nicely into a call to C<pthread_atfork>: |
500 | |
502 | |
501 | pthread_atfork (0, 0, ev_default_fork); |
503 | pthread_atfork (0, 0, ev_default_fork); |
502 | |
|
|
503 | At the moment, C<EVBACKEND_SELECT> and C<EVBACKEND_POLL> are safe to use |
|
|
504 | without calling this function, so if you force one of those backends you |
|
|
505 | do not need to care. |
|
|
506 | |
504 | |
507 | =item ev_loop_fork (loop) |
505 | =item ev_loop_fork (loop) |
508 | |
506 | |
509 | 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 |
510 | 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 |
… | |
… | |
776 | =item C<EV_FORK> |
774 | =item C<EV_FORK> |
777 | |
775 | |
778 | The event loop has been resumed in the child process after fork (see |
776 | The event loop has been resumed in the child process after fork (see |
779 | C<ev_fork>). |
777 | C<ev_fork>). |
780 | |
778 | |
|
|
779 | =item C<EV_ASYNC> |
|
|
780 | |
|
|
781 | The given async watcher has been asynchronously notified (see C<ev_async>). |
|
|
782 | |
781 | =item C<EV_ERROR> |
783 | =item C<EV_ERROR> |
782 | |
784 | |
783 | An unspecified error has occured, the watcher has been stopped. This might |
785 | An unspecified error has occured, the watcher has been stopped. This might |
784 | happen because the watcher could not be properly started because libev |
786 | happen because the watcher could not be properly started because libev |
785 | ran out of memory, a file descriptor was found to be closed or any other |
787 | ran out of memory, a file descriptor was found to be closed or any other |
… | |
… | |
1440 | |
1442 | |
1441 | =head3 Watcher-Specific Functions and Data Members |
1443 | =head3 Watcher-Specific Functions and Data Members |
1442 | |
1444 | |
1443 | =over 4 |
1445 | =over 4 |
1444 | |
1446 | |
1445 | =item ev_child_init (ev_child *, callback, int pid) |
1447 | =item ev_child_init (ev_child *, callback, int pid, int trace) |
1446 | |
1448 | |
1447 | =item ev_child_set (ev_child *, int pid) |
1449 | =item ev_child_set (ev_child *, int pid, int trace) |
1448 | |
1450 | |
1449 | Configures the watcher to wait for status changes of process C<pid> (or |
1451 | Configures the watcher to wait for status changes of process C<pid> (or |
1450 | I<any> process if C<pid> is specified as C<0>). The callback can look |
1452 | I<any> process if C<pid> is specified as C<0>). The callback can look |
1451 | at the C<rstatus> member of the C<ev_child> watcher structure to see |
1453 | at the C<rstatus> member of the C<ev_child> watcher structure to see |
1452 | the status word (use the macros from C<sys/wait.h> and see your systems |
1454 | the status word (use the macros from C<sys/wait.h> and see your systems |
1453 | C<waitpid> documentation). The C<rpid> member contains the pid of the |
1455 | C<waitpid> documentation). The C<rpid> member contains the pid of the |
1454 | process causing the status change. |
1456 | process causing the status change. C<trace> must be either C<0> (only |
|
|
1457 | activate the watcher when the process terminates) or C<1> (additionally |
|
|
1458 | activate the watcher when the process is stopped or continued). |
1455 | |
1459 | |
1456 | =item int pid [read-only] |
1460 | =item int pid [read-only] |
1457 | |
1461 | |
1458 | The process id this watcher watches out for, or C<0>, meaning any process id. |
1462 | The process id this watcher watches out for, or C<0>, meaning any process id. |
1459 | |
1463 | |
… | |
… | |
1695 | static void |
1699 | static void |
1696 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1700 | idle_cb (struct ev_loop *loop, struct ev_idle *w, int revents) |
1697 | { |
1701 | { |
1698 | free (w); |
1702 | free (w); |
1699 | // now do something you wanted to do when the program has |
1703 | // now do something you wanted to do when the program has |
1700 | // no longer asnything immediate to do. |
1704 | // no longer anything immediate to do. |
1701 | } |
1705 | } |
1702 | |
1706 | |
1703 | struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1707 | struct ev_idle *idle_watcher = malloc (sizeof (struct ev_idle)); |
1704 | ev_idle_init (idle_watcher, idle_cb); |
1708 | ev_idle_init (idle_watcher, idle_cb); |
1705 | ev_idle_start (loop, idle_cb); |
1709 | ev_idle_start (loop, idle_cb); |
… | |
… | |
2046 | believe me. |
2050 | believe me. |
2047 | |
2051 | |
2048 | =back |
2052 | =back |
2049 | |
2053 | |
2050 | |
2054 | |
|
|
2055 | =head2 C<ev_async> - how to wake up another event loop |
|
|
2056 | |
|
|
2057 | In general, you cannot use an C<ev_loop> from multiple threads or other |
|
|
2058 | asynchronous sources such as signal handlers (as opposed to multiple event |
|
|
2059 | loops - those are of course safe to use in different threads). |
|
|
2060 | |
|
|
2061 | Sometimes, however, you need to wake up another event loop you do not |
|
|
2062 | control, for example because it belongs to another thread. This is what |
|
|
2063 | C<ev_async> watchers do: as long as the C<ev_async> watcher is active, you |
|
|
2064 | can signal it by calling C<ev_async_send>, which is thread- and signal |
|
|
2065 | safe. |
|
|
2066 | |
|
|
2067 | This functionality is very similar to C<ev_signal> watchers, as signals, |
|
|
2068 | too, are asynchronous in nature, and signals, too, will be compressed |
|
|
2069 | (i.e. the number of callback invocations may be less than the number of |
|
|
2070 | C<ev_async_sent> calls). |
|
|
2071 | |
|
|
2072 | Unlike C<ev_signal> watchers, C<ev_async> works with any event loop, not |
|
|
2073 | just the default loop. |
|
|
2074 | |
|
|
2075 | =head3 Watcher-Specific Functions and Data Members |
|
|
2076 | |
|
|
2077 | =over 4 |
|
|
2078 | |
|
|
2079 | =item ev_async_init (ev_async *, callback) |
|
|
2080 | |
|
|
2081 | Initialises and configures the async watcher - it has no parameters of any |
|
|
2082 | kind. There is a C<ev_asynd_set> macro, but using it is utterly pointless, |
|
|
2083 | believe me. |
|
|
2084 | |
|
|
2085 | =item ev_async_send (loop, ev_async *) |
|
|
2086 | |
|
|
2087 | Sends/signals/activates the given C<ev_async> watcher, that is, feeds |
|
|
2088 | an C<EV_ASYNC> event on the watcher into the event loop. Unlike |
|
|
2089 | C<ev_feed_event>, this call is safe to do in other threads, signal or |
|
|
2090 | similar contexts (see the dicusssion of C<EV_ATOMIC_T> in the embedding |
|
|
2091 | section below on what exactly this means). |
|
|
2092 | |
|
|
2093 | This call incurs the overhead of a syscall only once per loop iteration, |
|
|
2094 | so while the overhead might be noticable, it doesn't apply to repeated |
|
|
2095 | calls to C<ev_async_send>. |
|
|
2096 | |
|
|
2097 | =back |
|
|
2098 | |
|
|
2099 | |
2051 | =head1 OTHER FUNCTIONS |
2100 | =head1 OTHER FUNCTIONS |
2052 | |
2101 | |
2053 | There are some other functions of possible interest. Described. Here. Now. |
2102 | There are some other functions of possible interest. Described. Here. Now. |
2054 | |
2103 | |
2055 | =over 4 |
2104 | =over 4 |
… | |
… | |
2282 | Example: Define a class with an IO and idle watcher, start one of them in |
2331 | Example: Define a class with an IO and idle watcher, start one of them in |
2283 | the constructor. |
2332 | the constructor. |
2284 | |
2333 | |
2285 | class myclass |
2334 | class myclass |
2286 | { |
2335 | { |
2287 | ev_io io; void io_cb (ev::io &w, int revents); |
2336 | ev::io io; void io_cb (ev::io &w, int revents); |
2288 | ev_idle idle void idle_cb (ev::idle &w, int revents); |
2337 | ev:idle idle void idle_cb (ev::idle &w, int revents); |
2289 | |
2338 | |
2290 | myclass (); |
2339 | myclass (int fd) |
2291 | } |
|
|
2292 | |
|
|
2293 | myclass::myclass (int fd) |
|
|
2294 | { |
2340 | { |
2295 | io .set <myclass, &myclass::io_cb > (this); |
2341 | io .set <myclass, &myclass::io_cb > (this); |
2296 | idle.set <myclass, &myclass::idle_cb> (this); |
2342 | idle.set <myclass, &myclass::idle_cb> (this); |
2297 | |
2343 | |
2298 | io.start (fd, ev::READ); |
2344 | io.start (fd, ev::READ); |
|
|
2345 | } |
2299 | } |
2346 | }; |
2300 | |
2347 | |
2301 | |
2348 | |
2302 | =head1 MACRO MAGIC |
2349 | =head1 MACRO MAGIC |
2303 | |
2350 | |
2304 | Libev can be compiled with a variety of options, the most fundamantal |
2351 | Libev can be compiled with a variety of options, the most fundamantal |
… | |
… | |
2560 | |
2607 | |
2561 | If defined to be C<1>, libev will compile in support for the Linux inotify |
2608 | If defined to be C<1>, libev will compile in support for the Linux inotify |
2562 | interface to speed up C<ev_stat> watchers. Its actual availability will |
2609 | interface to speed up C<ev_stat> watchers. Its actual availability will |
2563 | be detected at runtime. |
2610 | be detected at runtime. |
2564 | |
2611 | |
|
|
2612 | =item EV_ATOMIC_T |
|
|
2613 | |
|
|
2614 | Libev requires an integer type (suitable for storing C<0> or C<1>) whose |
|
|
2615 | access is atomic with respect to other threads or signal contexts. No such type |
|
|
2616 | is easily found using, so you cna provide your own type that you know is safe. |
|
|
2617 | |
|
|
2618 | In the absense of this define, libev will use C<sig_atomic_t volatile> |
|
|
2619 | from F<signal.h>, which is usually good enough on most platforms. |
|
|
2620 | |
2565 | =item EV_H |
2621 | =item EV_H |
2566 | |
2622 | |
2567 | The name of the F<ev.h> header file used to include it. The default if |
2623 | The name of the F<ev.h> header file used to include it. The default if |
2568 | undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be |
2624 | undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be |
2569 | used to virtually rename the F<ev.h> header file in case of conflicts. |
2625 | used to virtually rename the F<ev.h> header file in case of conflicts. |
… | |
… | |
2634 | defined to be C<0>, then they are not. |
2690 | defined to be C<0>, then they are not. |
2635 | |
2691 | |
2636 | =item EV_FORK_ENABLE |
2692 | =item EV_FORK_ENABLE |
2637 | |
2693 | |
2638 | If undefined or defined to be C<1>, then fork watchers are supported. If |
2694 | If undefined or defined to be C<1>, then fork watchers are supported. If |
|
|
2695 | defined to be C<0>, then they are not. |
|
|
2696 | |
|
|
2697 | =item EV_ASYNC_ENABLE |
|
|
2698 | |
|
|
2699 | If undefined or defined to be C<1>, then async watchers are supported. If |
2639 | defined to be C<0>, then they are not. |
2700 | defined to be C<0>, then they are not. |
2640 | |
2701 | |
2641 | =item EV_MINIMAL |
2702 | =item EV_MINIMAL |
2642 | |
2703 | |
2643 | If you need to shave off some kilobytes of code at the expense of some |
2704 | If you need to shave off some kilobytes of code at the expense of some |