… | |
… | |
98 | =head2 FEATURES |
98 | =head2 FEATURES |
99 | |
99 | |
100 | Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the |
100 | Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the |
101 | BSD-specific C<kqueue> and the Solaris-specific event port mechanisms |
101 | BSD-specific C<kqueue> and the Solaris-specific event port mechanisms |
102 | for file descriptor events (C<ev_io>), the Linux C<inotify> interface |
102 | for file descriptor events (C<ev_io>), the Linux C<inotify> interface |
103 | (for C<ev_stat>), relative timers (C<ev_timer>), absolute timers |
103 | (for C<ev_stat>), Linux eventfd/signalfd (for faster and cleaner |
104 | with customised rescheduling (C<ev_periodic>), synchronous signals |
104 | inter-thread wakeup (C<ev_async>)/signal handling (C<ev_signal>)) relative |
105 | (C<ev_signal>), process status change events (C<ev_child>), and event |
105 | timers (C<ev_timer>), absolute timers with customised rescheduling |
106 | watchers dealing with the event loop mechanism itself (C<ev_idle>, |
106 | (C<ev_periodic>), synchronous signals (C<ev_signal>), process status |
107 | C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as |
107 | change events (C<ev_child>), and event watchers dealing with the event |
108 | file watchers (C<ev_stat>) and even limited support for fork events |
108 | loop mechanism itself (C<ev_idle>, C<ev_embed>, C<ev_prepare> and |
109 | (C<ev_fork>). |
109 | C<ev_check> watchers) as well as file watchers (C<ev_stat>) and even |
|
|
110 | limited support for fork events (C<ev_fork>). |
110 | |
111 | |
111 | It also is quite fast (see this |
112 | It also is quite fast (see this |
112 | L<benchmark|http://libev.schmorp.de/bench.html> comparing it to libevent |
113 | L<benchmark|http://libev.schmorp.de/bench.html> comparing it to libevent |
113 | for example). |
114 | for example). |
114 | |
115 | |
… | |
… | |
117 | Libev is very configurable. In this manual the default (and most common) |
118 | Libev is very configurable. In this manual the default (and most common) |
118 | configuration will be described, which supports multiple event loops. For |
119 | configuration will be described, which supports multiple event loops. For |
119 | more info about various configuration options please have a look at |
120 | more info about various configuration options please have a look at |
120 | B<EMBED> section in this manual. If libev was configured without support |
121 | B<EMBED> section in this manual. If libev was configured without support |
121 | for multiple event loops, then all functions taking an initial argument of |
122 | for multiple event loops, then all functions taking an initial argument of |
122 | name C<loop> (which is always of type C<ev_loop *>) will not have |
123 | name C<loop> (which is always of type C<struct ev_loop *>) will not have |
123 | this argument. |
124 | this argument. |
124 | |
125 | |
125 | =head2 TIME REPRESENTATION |
126 | =head2 TIME REPRESENTATION |
126 | |
127 | |
127 | Libev represents time as a single floating point number, representing |
128 | Libev represents time as a single floating point number, representing |
… | |
… | |
362 | flag. |
363 | flag. |
363 | |
364 | |
364 | This flag setting cannot be overridden or specified in the C<LIBEV_FLAGS> |
365 | This flag setting cannot be overridden or specified in the C<LIBEV_FLAGS> |
365 | environment variable. |
366 | environment variable. |
366 | |
367 | |
|
|
368 | =item C<EVFLAG_NOINOTIFY> |
|
|
369 | |
|
|
370 | When this flag is specified, then libev will not attempt to use the |
|
|
371 | I<inotify> API for it's C<ev_stat> watchers. Apart from debugging and |
|
|
372 | testing, this flag can be useful to conserve inotify file descriptors, as |
|
|
373 | otherwise each loop using C<ev_stat> watchers consumes one inotify handle. |
|
|
374 | |
|
|
375 | =item C<EVFLAG_SIGNALFD> |
|
|
376 | |
|
|
377 | When this flag is specified, then libev will attempt to use the |
|
|
378 | I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This API |
|
|
379 | delivers signals synchronously, which makes is both faster and might make |
|
|
380 | it possible to get the queued signal data. |
|
|
381 | |
|
|
382 | Signalfd will not be used by default as this changes your signal mask, and |
|
|
383 | there are a lot of shoddy libraries and programs (glib's threadpool for |
|
|
384 | example) that can't properly initialise their signal masks. |
|
|
385 | |
367 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
386 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
368 | |
387 | |
369 | This is your standard select(2) backend. Not I<completely> standard, as |
388 | This is your standard select(2) backend. Not I<completely> standard, as |
370 | libev tries to roll its own fd_set with no limits on the number of fds, |
389 | libev tries to roll its own fd_set with no limits on the number of fds, |
371 | but if that fails, expect a fairly low limit on the number of fds when |
390 | but if that fails, expect a fairly low limit on the number of fds when |
… | |
… | |
394 | |
413 | |
395 | This backend maps C<EV_READ> to C<POLLIN | POLLERR | POLLHUP>, and |
414 | This backend maps C<EV_READ> to C<POLLIN | POLLERR | POLLHUP>, and |
396 | C<EV_WRITE> to C<POLLOUT | POLLERR | POLLHUP>. |
415 | C<EV_WRITE> to C<POLLOUT | POLLERR | POLLHUP>. |
397 | |
416 | |
398 | =item C<EVBACKEND_EPOLL> (value 4, Linux) |
417 | =item C<EVBACKEND_EPOLL> (value 4, Linux) |
|
|
418 | |
|
|
419 | Use the linux-specific epoll(7) interface (for both pre- and post-2.6.9 |
|
|
420 | kernels). |
399 | |
421 | |
400 | For few fds, this backend is a bit little slower than poll and select, |
422 | For few fds, this backend is a bit little slower than poll and select, |
401 | but it scales phenomenally better. While poll and select usually scale |
423 | but it scales phenomenally better. While poll and select usually scale |
402 | like O(total_fds) where n is the total number of fds (or the highest fd), |
424 | like O(total_fds) where n is the total number of fds (or the highest fd), |
403 | epoll scales either O(1) or O(active_fds). |
425 | epoll scales either O(1) or O(active_fds). |
… | |
… | |
518 | |
540 | |
519 | It is definitely not recommended to use this flag. |
541 | It is definitely not recommended to use this flag. |
520 | |
542 | |
521 | =back |
543 | =back |
522 | |
544 | |
523 | If one or more of these are or'ed into the flags value, then only these |
545 | If one or more of the backend flags are or'ed into the flags value, |
524 | backends will be tried (in the reverse order as listed here). If none are |
546 | then only these backends will be tried (in the reverse order as listed |
525 | specified, all backends in C<ev_recommended_backends ()> will be tried. |
547 | here). If none are specified, all backends in C<ev_recommended_backends |
|
|
548 | ()> will be tried. |
526 | |
549 | |
527 | Example: This is the most typical usage. |
550 | Example: This is the most typical usage. |
528 | |
551 | |
529 | if (!ev_default_loop (0)) |
552 | if (!ev_default_loop (0)) |
530 | fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?"); |
553 | fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?"); |
… | |
… | |
573 | as signal and child watchers) would need to be stopped manually. |
596 | as signal and child watchers) would need to be stopped manually. |
574 | |
597 | |
575 | In general it is not advisable to call this function except in the |
598 | In general it is not advisable to call this function except in the |
576 | rare occasion where you really need to free e.g. the signal handling |
599 | rare occasion where you really need to free e.g. the signal handling |
577 | pipe fds. If you need dynamically allocated loops it is better to use |
600 | pipe fds. If you need dynamically allocated loops it is better to use |
578 | C<ev_loop_new> and C<ev_loop_destroy>). |
601 | C<ev_loop_new> and C<ev_loop_destroy>. |
579 | |
602 | |
580 | =item ev_loop_destroy (loop) |
603 | =item ev_loop_destroy (loop) |
581 | |
604 | |
582 | Like C<ev_default_destroy>, but destroys an event loop created by an |
605 | Like C<ev_default_destroy>, but destroys an event loop created by an |
583 | earlier call to C<ev_loop_new>. |
606 | earlier call to C<ev_loop_new>. |
… | |
… | |
687 | event loop time (see C<ev_now_update>). |
710 | event loop time (see C<ev_now_update>). |
688 | |
711 | |
689 | =item ev_loop (loop, int flags) |
712 | =item ev_loop (loop, int flags) |
690 | |
713 | |
691 | Finally, this is it, the event handler. This function usually is called |
714 | Finally, this is it, the event handler. This function usually is called |
692 | after you initialised all your watchers and you want to start handling |
715 | after you have initialised all your watchers and you want to start |
693 | events. |
716 | handling events. |
694 | |
717 | |
695 | If the flags argument is specified as C<0>, it will not return until |
718 | If the flags argument is specified as C<0>, it will not return until |
696 | either no event watchers are active anymore or C<ev_unloop> was called. |
719 | either no event watchers are active anymore or C<ev_unloop> was called. |
697 | |
720 | |
698 | Please note that an explicit C<ev_unloop> is usually better than |
721 | Please note that an explicit C<ev_unloop> is usually better than |
… | |
… | |
772 | |
795 | |
773 | Ref/unref can be used to add or remove a reference count on the event |
796 | Ref/unref can be used to add or remove a reference count on the event |
774 | loop: Every watcher keeps one reference, and as long as the reference |
797 | loop: Every watcher keeps one reference, and as long as the reference |
775 | count is nonzero, C<ev_loop> will not return on its own. |
798 | count is nonzero, C<ev_loop> will not return on its own. |
776 | |
799 | |
777 | If you have a watcher you never unregister that should not keep C<ev_loop> |
800 | This is useful when you have a watcher that you never intend to |
778 | from returning, call ev_unref() after starting, and ev_ref() before |
801 | unregister, but that nevertheless should not keep C<ev_loop> from |
|
|
802 | returning. In such a case, call C<ev_unref> after starting, and C<ev_ref> |
779 | stopping it. |
803 | before stopping it. |
780 | |
804 | |
781 | As an example, libev itself uses this for its internal signal pipe: It |
805 | As an example, libev itself uses this for its internal signal pipe: It |
782 | is not visible to the libev user and should not keep C<ev_loop> from |
806 | is not visible to the libev user and should not keep C<ev_loop> from |
783 | exiting if no event watchers registered by it are active. It is also an |
807 | exiting if no event watchers registered by it are active. It is also an |
784 | excellent way to do this for generic recurring timers or from within |
808 | excellent way to do this for generic recurring timers or from within |
… | |
… | |
899 | |
923 | |
900 | While event loop modifications are allowed between invocations of |
924 | While event loop modifications are allowed between invocations of |
901 | C<release> and C<acquire> (that's their only purpose after all), no |
925 | C<release> and C<acquire> (that's their only purpose after all), no |
902 | modifications done will affect the event loop, i.e. adding watchers will |
926 | modifications done will affect the event loop, i.e. adding watchers will |
903 | have no effect on the set of file descriptors being watched, or the time |
927 | have no effect on the set of file descriptors being watched, or the time |
904 | waited. USe an C<ev_async> watcher to wake up C<ev_loop> when you want it |
928 | waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it |
905 | to take note of any changes you made. |
929 | to take note of any changes you made. |
906 | |
930 | |
907 | In theory, threads executing C<ev_loop> will be async-cancel safe between |
931 | In theory, threads executing C<ev_loop> will be async-cancel safe between |
908 | invocations of C<release> and C<acquire>. |
932 | invocations of C<release> and C<acquire>. |
909 | |
933 | |
… | |
… | |
1106 | |
1130 | |
1107 | ev_io w; |
1131 | ev_io w; |
1108 | ev_init (&w, my_cb); |
1132 | ev_init (&w, my_cb); |
1109 | ev_io_set (&w, STDIN_FILENO, EV_READ); |
1133 | ev_io_set (&w, STDIN_FILENO, EV_READ); |
1110 | |
1134 | |
1111 | =item C<ev_TYPE_set> (ev_TYPE *, [args]) |
1135 | =item C<ev_TYPE_set> (ev_TYPE *watcher, [args]) |
1112 | |
1136 | |
1113 | This macro initialises the type-specific parts of a watcher. You need to |
1137 | This macro initialises the type-specific parts of a watcher. You need to |
1114 | call C<ev_init> at least once before you call this macro, but you can |
1138 | call C<ev_init> at least once before you call this macro, but you can |
1115 | call C<ev_TYPE_set> any number of times. You must not, however, call this |
1139 | call C<ev_TYPE_set> any number of times. You must not, however, call this |
1116 | macro on a watcher that is active (it can be pending, however, which is a |
1140 | macro on a watcher that is active (it can be pending, however, which is a |
… | |
… | |
1129 | |
1153 | |
1130 | Example: Initialise and set an C<ev_io> watcher in one step. |
1154 | Example: Initialise and set an C<ev_io> watcher in one step. |
1131 | |
1155 | |
1132 | ev_io_init (&w, my_cb, STDIN_FILENO, EV_READ); |
1156 | ev_io_init (&w, my_cb, STDIN_FILENO, EV_READ); |
1133 | |
1157 | |
1134 | =item C<ev_TYPE_start> (loop *, ev_TYPE *watcher) |
1158 | =item C<ev_TYPE_start> (loop, ev_TYPE *watcher) |
1135 | |
1159 | |
1136 | Starts (activates) the given watcher. Only active watchers will receive |
1160 | Starts (activates) the given watcher. Only active watchers will receive |
1137 | events. If the watcher is already active nothing will happen. |
1161 | events. If the watcher is already active nothing will happen. |
1138 | |
1162 | |
1139 | Example: Start the C<ev_io> watcher that is being abused as example in this |
1163 | Example: Start the C<ev_io> watcher that is being abused as example in this |
1140 | whole section. |
1164 | whole section. |
1141 | |
1165 | |
1142 | ev_io_start (EV_DEFAULT_UC, &w); |
1166 | ev_io_start (EV_DEFAULT_UC, &w); |
1143 | |
1167 | |
1144 | =item C<ev_TYPE_stop> (loop *, ev_TYPE *watcher) |
1168 | =item C<ev_TYPE_stop> (loop, ev_TYPE *watcher) |
1145 | |
1169 | |
1146 | Stops the given watcher if active, and clears the pending status (whether |
1170 | Stops the given watcher if active, and clears the pending status (whether |
1147 | the watcher was active or not). |
1171 | the watcher was active or not). |
1148 | |
1172 | |
1149 | It is possible that stopped watchers are pending - for example, |
1173 | It is possible that stopped watchers are pending - for example, |
… | |
… | |
1174 | =item ev_cb_set (ev_TYPE *watcher, callback) |
1198 | =item ev_cb_set (ev_TYPE *watcher, callback) |
1175 | |
1199 | |
1176 | Change the callback. You can change the callback at virtually any time |
1200 | Change the callback. You can change the callback at virtually any time |
1177 | (modulo threads). |
1201 | (modulo threads). |
1178 | |
1202 | |
1179 | =item ev_set_priority (ev_TYPE *watcher, priority) |
1203 | =item ev_set_priority (ev_TYPE *watcher, int priority) |
1180 | |
1204 | |
1181 | =item int ev_priority (ev_TYPE *watcher) |
1205 | =item int ev_priority (ev_TYPE *watcher) |
1182 | |
1206 | |
1183 | Set and query the priority of the watcher. The priority is a small |
1207 | Set and query the priority of the watcher. The priority is a small |
1184 | integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI> |
1208 | integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI> |
… | |
… | |
1215 | returns its C<revents> bitset (as if its callback was invoked). If the |
1239 | returns its C<revents> bitset (as if its callback was invoked). If the |
1216 | watcher isn't pending it does nothing and returns C<0>. |
1240 | watcher isn't pending it does nothing and returns C<0>. |
1217 | |
1241 | |
1218 | Sometimes it can be useful to "poll" a watcher instead of waiting for its |
1242 | Sometimes it can be useful to "poll" a watcher instead of waiting for its |
1219 | callback to be invoked, which can be accomplished with this function. |
1243 | callback to be invoked, which can be accomplished with this function. |
|
|
1244 | |
|
|
1245 | =item ev_feed_event (loop, ev_TYPE *watcher, int revents) |
|
|
1246 | |
|
|
1247 | Feeds the given event set into the event loop, as if the specified event |
|
|
1248 | had happened for the specified watcher (which must be a pointer to an |
|
|
1249 | initialised but not necessarily started event watcher). Obviously you must |
|
|
1250 | not free the watcher as long as it has pending events. |
|
|
1251 | |
|
|
1252 | Stopping the watcher, letting libev invoke it, or calling |
|
|
1253 | C<ev_clear_pending> will clear the pending event, even if the watcher was |
|
|
1254 | not started in the first place. |
|
|
1255 | |
|
|
1256 | See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related |
|
|
1257 | functions that do not need a watcher. |
1220 | |
1258 | |
1221 | =back |
1259 | =back |
1222 | |
1260 | |
1223 | |
1261 | |
1224 | =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER |
1262 | =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER |
… | |
… | |
1820 | C<repeat> value), or reset the running timer to the C<repeat> value. |
1858 | C<repeat> value), or reset the running timer to the C<repeat> value. |
1821 | |
1859 | |
1822 | This sounds a bit complicated, see L<Be smart about timeouts>, above, for a |
1860 | This sounds a bit complicated, see L<Be smart about timeouts>, above, for a |
1823 | usage example. |
1861 | usage example. |
1824 | |
1862 | |
1825 | =item ev_timer_remaining (loop, ev_timer *) |
1863 | =item ev_tstamp ev_timer_remaining (loop, ev_timer *) |
1826 | |
1864 | |
1827 | Returns the remaining time until a timer fires. If the timer is active, |
1865 | Returns the remaining time until a timer fires. If the timer is active, |
1828 | then this time is relative to the current event loop time, otherwise it's |
1866 | then this time is relative to the current event loop time, otherwise it's |
1829 | the timeout value currently configured. |
1867 | the timeout value currently configured. |
1830 | |
1868 | |
… | |
… | |
2076 | Signal watchers will trigger an event when the process receives a specific |
2114 | Signal watchers will trigger an event when the process receives a specific |
2077 | signal one or more times. Even though signals are very asynchronous, libev |
2115 | signal one or more times. Even though signals are very asynchronous, libev |
2078 | will try it's best to deliver signals synchronously, i.e. as part of the |
2116 | will try it's best to deliver signals synchronously, i.e. as part of the |
2079 | normal event processing, like any other event. |
2117 | normal event processing, like any other event. |
2080 | |
2118 | |
2081 | If you want signals asynchronously, just use C<sigaction> as you would |
2119 | If you want signals to be delivered truly asynchronously, just use |
2082 | do without libev and forget about sharing the signal. You can even use |
2120 | C<sigaction> as you would do without libev and forget about sharing |
2083 | C<ev_async> from a signal handler to synchronously wake up an event loop. |
2121 | the signal. You can even use C<ev_async> from a signal handler to |
|
|
2122 | synchronously wake up an event loop. |
2084 | |
2123 | |
2085 | You can configure as many watchers as you like per signal. Only when the |
2124 | You can configure as many watchers as you like for the same signal, but |
|
|
2125 | only within the same loop, i.e. you can watch for C<SIGINT> in your |
|
|
2126 | default loop and for C<SIGIO> in another loop, but you cannot watch for |
|
|
2127 | C<SIGINT> in both the default loop and another loop at the same time. At |
|
|
2128 | the moment, C<SIGCHLD> is permanently tied to the default loop. |
|
|
2129 | |
2086 | first watcher gets started will libev actually register a signal handler |
2130 | When the first watcher gets started will libev actually register something |
2087 | with the kernel (thus it coexists with your own signal handlers as long as |
2131 | with the kernel (thus it coexists with your own signal handlers as long as |
2088 | you don't register any with libev for the same signal). Similarly, when |
2132 | you don't register any with libev for the same signal). |
2089 | the last signal watcher for a signal is stopped, libev will reset the |
|
|
2090 | signal handler to SIG_DFL (regardless of what it was set to before). |
|
|
2091 | |
2133 | |
2092 | If possible and supported, libev will install its handlers with |
2134 | If possible and supported, libev will install its handlers with |
2093 | C<SA_RESTART> behaviour enabled, so system calls should not be unduly |
2135 | C<SA_RESTART> (or equivalent) behaviour enabled, so system calls should |
2094 | interrupted. If you have a problem with system calls getting interrupted by |
2136 | not be unduly interrupted. If you have a problem with system calls getting |
2095 | signals you can block all signals in an C<ev_check> watcher and unblock |
2137 | interrupted by signals you can block all signals in an C<ev_check> watcher |
2096 | them in an C<ev_prepare> watcher. |
2138 | and unblock them in an C<ev_prepare> watcher. |
|
|
2139 | |
|
|
2140 | =head3 The special problem of inheritance over fork/execve/pthread_create |
|
|
2141 | |
|
|
2142 | Both the signal mask (C<sigprocmask>) and the signal disposition |
|
|
2143 | (C<sigaction>) are unspecified after starting a signal watcher (and after |
|
|
2144 | stopping it again), that is, libev might or might not block the signal, |
|
|
2145 | and might or might not set or restore the installed signal handler. |
|
|
2146 | |
|
|
2147 | While this does not matter for the signal disposition (libev never |
|
|
2148 | sets signals to C<SIG_IGN>, so handlers will be reset to C<SIG_DFL> on |
|
|
2149 | C<execve>), this matters for the signal mask: many programs do not expect |
|
|
2150 | certain signals to be blocked. |
|
|
2151 | |
|
|
2152 | This means that before calling C<exec> (from the child) you should reset |
|
|
2153 | the signal mask to whatever "default" you expect (all clear is a good |
|
|
2154 | choice usually). |
|
|
2155 | |
|
|
2156 | The simplest way to ensure that the signal mask is reset in the child is |
|
|
2157 | to install a fork handler with C<pthread_atfork> that resets it. That will |
|
|
2158 | catch fork calls done by libraries (such as the libc) as well. |
|
|
2159 | |
|
|
2160 | In current versions of libev, the signal will not be blocked indefinitely |
|
|
2161 | unless you use the C<signalfd> API (C<EV_SIGNALFD>). While this reduces |
|
|
2162 | the window of opportunity for problems, it will not go away, as libev |
|
|
2163 | I<has> to modify the signal mask, at least temporarily. |
|
|
2164 | |
|
|
2165 | So I can't stress this enough I<if you do not reset your signal mask |
|
|
2166 | when you expect it to be empty, you have a race condition in your |
|
|
2167 | program>. This is not a libev-specific thing, this is true for most event |
|
|
2168 | libraries. |
2097 | |
2169 | |
2098 | =head3 Watcher-Specific Functions and Data Members |
2170 | =head3 Watcher-Specific Functions and Data Members |
2099 | |
2171 | |
2100 | =over 4 |
2172 | =over 4 |
2101 | |
2173 | |
… | |
… | |
2146 | libev) |
2218 | libev) |
2147 | |
2219 | |
2148 | =head3 Process Interaction |
2220 | =head3 Process Interaction |
2149 | |
2221 | |
2150 | Libev grabs C<SIGCHLD> as soon as the default event loop is |
2222 | Libev grabs C<SIGCHLD> as soon as the default event loop is |
2151 | initialised. This is necessary to guarantee proper behaviour even if |
2223 | initialised. This is necessary to guarantee proper behaviour even if the |
2152 | the first child watcher is started after the child exits. The occurrence |
2224 | first child watcher is started after the child exits. The occurrence |
2153 | of C<SIGCHLD> is recorded asynchronously, but child reaping is done |
2225 | of C<SIGCHLD> is recorded asynchronously, but child reaping is done |
2154 | synchronously as part of the event loop processing. Libev always reaps all |
2226 | synchronously as part of the event loop processing. Libev always reaps all |
2155 | children, even ones not watched. |
2227 | children, even ones not watched. |
2156 | |
2228 | |
2157 | =head3 Overriding the Built-In Processing |
2229 | =head3 Overriding the Built-In Processing |
… | |
… | |
2167 | =head3 Stopping the Child Watcher |
2239 | =head3 Stopping the Child Watcher |
2168 | |
2240 | |
2169 | Currently, the child watcher never gets stopped, even when the |
2241 | Currently, the child watcher never gets stopped, even when the |
2170 | child terminates, so normally one needs to stop the watcher in the |
2242 | child terminates, so normally one needs to stop the watcher in the |
2171 | callback. Future versions of libev might stop the watcher automatically |
2243 | callback. Future versions of libev might stop the watcher automatically |
2172 | when a child exit is detected. |
2244 | when a child exit is detected (calling C<ev_child_stop> twice is not a |
|
|
2245 | problem). |
2173 | |
2246 | |
2174 | =head3 Watcher-Specific Functions and Data Members |
2247 | =head3 Watcher-Specific Functions and Data Members |
2175 | |
2248 | |
2176 | =over 4 |
2249 | =over 4 |
2177 | |
2250 | |
… | |
… | |
2917 | =head3 Queueing |
2990 | =head3 Queueing |
2918 | |
2991 | |
2919 | C<ev_async> does not support queueing of data in any way. The reason |
2992 | C<ev_async> does not support queueing of data in any way. The reason |
2920 | is that the author does not know of a simple (or any) algorithm for a |
2993 | is that the author does not know of a simple (or any) algorithm for a |
2921 | multiple-writer-single-reader queue that works in all cases and doesn't |
2994 | multiple-writer-single-reader queue that works in all cases and doesn't |
2922 | need elaborate support such as pthreads. |
2995 | need elaborate support such as pthreads or unportable memory access |
|
|
2996 | semantics. |
2923 | |
2997 | |
2924 | That means that if you want to queue data, you have to provide your own |
2998 | That means that if you want to queue data, you have to provide your own |
2925 | queue. But at least I can tell you how to implement locking around your |
2999 | queue. But at least I can tell you how to implement locking around your |
2926 | queue: |
3000 | queue: |
2927 | |
3001 | |
… | |
… | |
3085 | /* doh, nothing entered */; |
3159 | /* doh, nothing entered */; |
3086 | } |
3160 | } |
3087 | |
3161 | |
3088 | ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
3162 | ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
3089 | |
3163 | |
3090 | =item ev_feed_event (struct ev_loop *, watcher *, int revents) |
|
|
3091 | |
|
|
3092 | Feeds the given event set into the event loop, as if the specified event |
|
|
3093 | had happened for the specified watcher (which must be a pointer to an |
|
|
3094 | initialised but not necessarily started event watcher). |
|
|
3095 | |
|
|
3096 | =item ev_feed_fd_event (struct ev_loop *, int fd, int revents) |
3164 | =item ev_feed_fd_event (loop, int fd, int revents) |
3097 | |
3165 | |
3098 | Feed an event on the given fd, as if a file descriptor backend detected |
3166 | Feed an event on the given fd, as if a file descriptor backend detected |
3099 | the given events it. |
3167 | the given events it. |
3100 | |
3168 | |
3101 | =item ev_feed_signal_event (struct ev_loop *loop, int signum) |
3169 | =item ev_feed_signal_event (loop, int signum) |
3102 | |
3170 | |
3103 | Feed an event as if the given signal occurred (C<loop> must be the default |
3171 | Feed an event as if the given signal occurred (C<loop> must be the default |
3104 | loop!). |
3172 | loop!). |
3105 | |
3173 | |
3106 | =back |
3174 | =back |
… | |
… | |
3186 | |
3254 | |
3187 | =over 4 |
3255 | =over 4 |
3188 | |
3256 | |
3189 | =item ev::TYPE::TYPE () |
3257 | =item ev::TYPE::TYPE () |
3190 | |
3258 | |
3191 | =item ev::TYPE::TYPE (struct ev_loop *) |
3259 | =item ev::TYPE::TYPE (loop) |
3192 | |
3260 | |
3193 | =item ev::TYPE::~TYPE |
3261 | =item ev::TYPE::~TYPE |
3194 | |
3262 | |
3195 | The constructor (optionally) takes an event loop to associate the watcher |
3263 | The constructor (optionally) takes an event loop to associate the watcher |
3196 | with. If it is omitted, it will use C<EV_DEFAULT>. |
3264 | with. If it is omitted, it will use C<EV_DEFAULT>. |
… | |
… | |
3273 | Example: Use a plain function as callback. |
3341 | Example: Use a plain function as callback. |
3274 | |
3342 | |
3275 | static void io_cb (ev::io &w, int revents) { } |
3343 | static void io_cb (ev::io &w, int revents) { } |
3276 | iow.set <io_cb> (); |
3344 | iow.set <io_cb> (); |
3277 | |
3345 | |
3278 | =item w->set (struct ev_loop *) |
3346 | =item w->set (loop) |
3279 | |
3347 | |
3280 | Associates a different C<struct ev_loop> with this watcher. You can only |
3348 | Associates a different C<struct ev_loop> with this watcher. You can only |
3281 | do this when the watcher is inactive (and not pending either). |
3349 | do this when the watcher is inactive (and not pending either). |
3282 | |
3350 | |
3283 | =item w->set ([arguments]) |
3351 | =item w->set ([arguments]) |
… | |
… | |
3380 | =item Ocaml |
3448 | =item Ocaml |
3381 | |
3449 | |
3382 | Erkki Seppala has written Ocaml bindings for libev, to be found at |
3450 | Erkki Seppala has written Ocaml bindings for libev, to be found at |
3383 | L<http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>. |
3451 | L<http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>. |
3384 | |
3452 | |
|
|
3453 | =item Lua |
|
|
3454 | |
|
|
3455 | Brian Maher has written a partial interface to libev |
|
|
3456 | for lua (only C<ev_io> and C<ev_timer>), to be found at |
|
|
3457 | L<http://github.com/brimworks/lua-ev>. |
|
|
3458 | |
3385 | =back |
3459 | =back |
3386 | |
3460 | |
3387 | |
3461 | |
3388 | =head1 MACRO MAGIC |
3462 | =head1 MACRO MAGIC |
3389 | |
3463 | |
… | |
… | |
3555 | keeps libev from including F<config.h>, and it also defines dummy |
3629 | keeps libev from including F<config.h>, and it also defines dummy |
3556 | implementations for some libevent functions (such as logging, which is not |
3630 | implementations for some libevent functions (such as logging, which is not |
3557 | supported). It will also not define any of the structs usually found in |
3631 | supported). It will also not define any of the structs usually found in |
3558 | F<event.h> that are not directly supported by the libev core alone. |
3632 | F<event.h> that are not directly supported by the libev core alone. |
3559 | |
3633 | |
3560 | In stanbdalone mode, libev will still try to automatically deduce the |
3634 | In standalone mode, libev will still try to automatically deduce the |
3561 | configuration, but has to be more conservative. |
3635 | configuration, but has to be more conservative. |
3562 | |
3636 | |
3563 | =item EV_USE_MONOTONIC |
3637 | =item EV_USE_MONOTONIC |
3564 | |
3638 | |
3565 | If defined to be C<1>, libev will try to detect the availability of the |
3639 | If defined to be C<1>, libev will try to detect the availability of the |
… | |
… | |
3630 | be used is the winsock select). This means that it will call |
3704 | be used is the winsock select). This means that it will call |
3631 | C<_get_osfhandle> on the fd to convert it to an OS handle. Otherwise, |
3705 | C<_get_osfhandle> on the fd to convert it to an OS handle. Otherwise, |
3632 | it is assumed that all these functions actually work on fds, even |
3706 | it is assumed that all these functions actually work on fds, even |
3633 | on win32. Should not be defined on non-win32 platforms. |
3707 | on win32. Should not be defined on non-win32 platforms. |
3634 | |
3708 | |
3635 | =item EV_FD_TO_WIN32_HANDLE |
3709 | =item EV_FD_TO_WIN32_HANDLE(fd) |
3636 | |
3710 | |
3637 | If C<EV_SELECT_IS_WINSOCKET> is enabled, then libev needs a way to map |
3711 | If C<EV_SELECT_IS_WINSOCKET> is enabled, then libev needs a way to map |
3638 | file descriptors to socket handles. When not defining this symbol (the |
3712 | file descriptors to socket handles. When not defining this symbol (the |
3639 | default), then libev will call C<_get_osfhandle>, which is usually |
3713 | default), then libev will call C<_get_osfhandle>, which is usually |
3640 | correct. In some cases, programs use their own file descriptor management, |
3714 | correct. In some cases, programs use their own file descriptor management, |
3641 | in which case they can provide this function to map fds to socket handles. |
3715 | in which case they can provide this function to map fds to socket handles. |
|
|
3716 | |
|
|
3717 | =item EV_WIN32_HANDLE_TO_FD(handle) |
|
|
3718 | |
|
|
3719 | If C<EV_SELECT_IS_WINSOCKET> then libev maps handles to file descriptors |
|
|
3720 | using the standard C<_open_osfhandle> function. For programs implementing |
|
|
3721 | their own fd to handle mapping, overwriting this function makes it easier |
|
|
3722 | to do so. This can be done by defining this macro to an appropriate value. |
|
|
3723 | |
|
|
3724 | =item EV_WIN32_CLOSE_FD(fd) |
|
|
3725 | |
|
|
3726 | If programs implement their own fd to handle mapping on win32, then this |
|
|
3727 | macro can be used to override the C<close> function, useful to unregister |
|
|
3728 | file descriptors again. Note that the replacement function has to close |
|
|
3729 | the underlying OS handle. |
3642 | |
3730 | |
3643 | =item EV_USE_POLL |
3731 | =item EV_USE_POLL |
3644 | |
3732 | |
3645 | If defined to be C<1>, libev will compile in support for the C<poll>(2) |
3733 | If defined to be C<1>, libev will compile in support for the C<poll>(2) |
3646 | backend. Otherwise it will be enabled on non-win32 platforms. It |
3734 | backend. Otherwise it will be enabled on non-win32 platforms. It |
… | |
… | |
3792 | Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to |
3880 | Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to |
3793 | provide a bare-bones event library. See C<ev.h> for details on what parts |
3881 | provide a bare-bones event library. See C<ev.h> for details on what parts |
3794 | of the API are still available, and do not complain if this subset changes |
3882 | of the API are still available, and do not complain if this subset changes |
3795 | over time. |
3883 | over time. |
3796 | |
3884 | |
|
|
3885 | =item EV_NSIG |
|
|
3886 | |
|
|
3887 | The highest supported signal number, +1 (or, the number of |
|
|
3888 | signals): Normally, libev tries to deduce the maximum number of signals |
|
|
3889 | automatically, but sometimes this fails, in which case it can be |
|
|
3890 | specified. Also, using a lower number than detected (C<32> should be |
|
|
3891 | good for about any system in existance) can save some memory, as libev |
|
|
3892 | statically allocates some 12-24 bytes per signal number. |
|
|
3893 | |
3797 | =item EV_PID_HASHSIZE |
3894 | =item EV_PID_HASHSIZE |
3798 | |
3895 | |
3799 | C<ev_child> watchers use a small hash table to distribute workload by |
3896 | C<ev_child> watchers use a small hash table to distribute workload by |
3800 | pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more |
3897 | pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more |
3801 | than enough. If you need to manage thousands of children you might want to |
3898 | than enough. If you need to manage thousands of children you might want to |