… | |
… | |
118 | 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) |
119 | configuration will be described, which supports multiple event loops. For |
119 | configuration will be described, which supports multiple event loops. For |
120 | more info about various configuration options please have a look at |
120 | more info about various configuration options please have a look at |
121 | 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 |
122 | 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 |
123 | 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 |
124 | this argument. |
124 | this argument. |
125 | |
125 | |
126 | =head2 TIME REPRESENTATION |
126 | =head2 TIME REPRESENTATION |
127 | |
127 | |
128 | Libev represents time as a single floating point number, representing |
128 | Libev represents time as a single floating point number, representing |
… | |
… | |
370 | When this flag is specified, then libev will not attempt to use the |
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 |
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 |
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. |
373 | otherwise each loop using C<ev_stat> watchers consumes one inotify handle. |
374 | |
374 | |
375 | =item C<EVFLAG_NOSIGNALFD> |
375 | =item C<EVFLAG_NOSIGFD> |
376 | |
376 | |
377 | When this flag is specified, then libev will not attempt to use the |
377 | When this flag is specified, then libev will not attempt to use the |
378 | I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This is |
378 | I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This is |
379 | probably only useful to work around any bugs in libev. Consequently, this |
379 | probably only useful to work around any bugs in libev. Consequently, this |
380 | flag might go away once the signalfd functionality is considered stable, |
380 | flag might go away once the signalfd functionality is considered stable, |
… | |
… | |
410 | |
410 | |
411 | This backend maps C<EV_READ> to C<POLLIN | POLLERR | POLLHUP>, and |
411 | This backend maps C<EV_READ> to C<POLLIN | POLLERR | POLLHUP>, and |
412 | C<EV_WRITE> to C<POLLOUT | POLLERR | POLLHUP>. |
412 | C<EV_WRITE> to C<POLLOUT | POLLERR | POLLHUP>. |
413 | |
413 | |
414 | =item C<EVBACKEND_EPOLL> (value 4, Linux) |
414 | =item C<EVBACKEND_EPOLL> (value 4, Linux) |
|
|
415 | |
|
|
416 | Use the linux-specific epoll(7) interface (for both pre- and post-2.6.9 |
|
|
417 | kernels). |
415 | |
418 | |
416 | For few fds, this backend is a bit little slower than poll and select, |
419 | For few fds, this backend is a bit little slower than poll and select, |
417 | but it scales phenomenally better. While poll and select usually scale |
420 | but it scales phenomenally better. While poll and select usually scale |
418 | like O(total_fds) where n is the total number of fds (or the highest fd), |
421 | like O(total_fds) where n is the total number of fds (or the highest fd), |
419 | epoll scales either O(1) or O(active_fds). |
422 | epoll scales either O(1) or O(active_fds). |
… | |
… | |
789 | |
792 | |
790 | Ref/unref can be used to add or remove a reference count on the event |
793 | Ref/unref can be used to add or remove a reference count on the event |
791 | loop: Every watcher keeps one reference, and as long as the reference |
794 | loop: Every watcher keeps one reference, and as long as the reference |
792 | count is nonzero, C<ev_loop> will not return on its own. |
795 | count is nonzero, C<ev_loop> will not return on its own. |
793 | |
796 | |
794 | If you have a watcher you never unregister that should not keep C<ev_loop> |
797 | This is useful when you have a watcher that you never intend to |
795 | from returning, call ev_unref() after starting, and ev_ref() before |
798 | unregister, but that nevertheless should not keep C<ev_loop> from |
|
|
799 | returning. In such a case, call C<ev_unref> after starting, and C<ev_ref> |
796 | stopping it. |
800 | before stopping it. |
797 | |
801 | |
798 | As an example, libev itself uses this for its internal signal pipe: It |
802 | As an example, libev itself uses this for its internal signal pipe: It |
799 | is not visible to the libev user and should not keep C<ev_loop> from |
803 | is not visible to the libev user and should not keep C<ev_loop> from |
800 | exiting if no event watchers registered by it are active. It is also an |
804 | exiting if no event watchers registered by it are active. It is also an |
801 | excellent way to do this for generic recurring timers or from within |
805 | excellent way to do this for generic recurring timers or from within |
… | |
… | |
916 | |
920 | |
917 | While event loop modifications are allowed between invocations of |
921 | While event loop modifications are allowed between invocations of |
918 | C<release> and C<acquire> (that's their only purpose after all), no |
922 | C<release> and C<acquire> (that's their only purpose after all), no |
919 | modifications done will affect the event loop, i.e. adding watchers will |
923 | modifications done will affect the event loop, i.e. adding watchers will |
920 | have no effect on the set of file descriptors being watched, or the time |
924 | have no effect on the set of file descriptors being watched, or the time |
921 | waited. USe an C<ev_async> watcher to wake up C<ev_loop> when you want it |
925 | waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it |
922 | to take note of any changes you made. |
926 | to take note of any changes you made. |
923 | |
927 | |
924 | In theory, threads executing C<ev_loop> will be async-cancel safe between |
928 | In theory, threads executing C<ev_loop> will be async-cancel safe between |
925 | invocations of C<release> and C<acquire>. |
929 | invocations of C<release> and C<acquire>. |
926 | |
930 | |
… | |
… | |
1123 | |
1127 | |
1124 | ev_io w; |
1128 | ev_io w; |
1125 | ev_init (&w, my_cb); |
1129 | ev_init (&w, my_cb); |
1126 | ev_io_set (&w, STDIN_FILENO, EV_READ); |
1130 | ev_io_set (&w, STDIN_FILENO, EV_READ); |
1127 | |
1131 | |
1128 | =item C<ev_TYPE_set> (ev_TYPE *, [args]) |
1132 | =item C<ev_TYPE_set> (ev_TYPE *watcher, [args]) |
1129 | |
1133 | |
1130 | This macro initialises the type-specific parts of a watcher. You need to |
1134 | This macro initialises the type-specific parts of a watcher. You need to |
1131 | call C<ev_init> at least once before you call this macro, but you can |
1135 | call C<ev_init> at least once before you call this macro, but you can |
1132 | call C<ev_TYPE_set> any number of times. You must not, however, call this |
1136 | call C<ev_TYPE_set> any number of times. You must not, however, call this |
1133 | macro on a watcher that is active (it can be pending, however, which is a |
1137 | macro on a watcher that is active (it can be pending, however, which is a |
… | |
… | |
1146 | |
1150 | |
1147 | Example: Initialise and set an C<ev_io> watcher in one step. |
1151 | Example: Initialise and set an C<ev_io> watcher in one step. |
1148 | |
1152 | |
1149 | ev_io_init (&w, my_cb, STDIN_FILENO, EV_READ); |
1153 | ev_io_init (&w, my_cb, STDIN_FILENO, EV_READ); |
1150 | |
1154 | |
1151 | =item C<ev_TYPE_start> (loop *, ev_TYPE *watcher) |
1155 | =item C<ev_TYPE_start> (loop, ev_TYPE *watcher) |
1152 | |
1156 | |
1153 | Starts (activates) the given watcher. Only active watchers will receive |
1157 | Starts (activates) the given watcher. Only active watchers will receive |
1154 | events. If the watcher is already active nothing will happen. |
1158 | events. If the watcher is already active nothing will happen. |
1155 | |
1159 | |
1156 | Example: Start the C<ev_io> watcher that is being abused as example in this |
1160 | Example: Start the C<ev_io> watcher that is being abused as example in this |
1157 | whole section. |
1161 | whole section. |
1158 | |
1162 | |
1159 | ev_io_start (EV_DEFAULT_UC, &w); |
1163 | ev_io_start (EV_DEFAULT_UC, &w); |
1160 | |
1164 | |
1161 | =item C<ev_TYPE_stop> (loop *, ev_TYPE *watcher) |
1165 | =item C<ev_TYPE_stop> (loop, ev_TYPE *watcher) |
1162 | |
1166 | |
1163 | Stops the given watcher if active, and clears the pending status (whether |
1167 | Stops the given watcher if active, and clears the pending status (whether |
1164 | the watcher was active or not). |
1168 | the watcher was active or not). |
1165 | |
1169 | |
1166 | It is possible that stopped watchers are pending - for example, |
1170 | It is possible that stopped watchers are pending - for example, |
… | |
… | |
1191 | =item ev_cb_set (ev_TYPE *watcher, callback) |
1195 | =item ev_cb_set (ev_TYPE *watcher, callback) |
1192 | |
1196 | |
1193 | Change the callback. You can change the callback at virtually any time |
1197 | Change the callback. You can change the callback at virtually any time |
1194 | (modulo threads). |
1198 | (modulo threads). |
1195 | |
1199 | |
1196 | =item ev_set_priority (ev_TYPE *watcher, priority) |
1200 | =item ev_set_priority (ev_TYPE *watcher, int priority) |
1197 | |
1201 | |
1198 | =item int ev_priority (ev_TYPE *watcher) |
1202 | =item int ev_priority (ev_TYPE *watcher) |
1199 | |
1203 | |
1200 | Set and query the priority of the watcher. The priority is a small |
1204 | Set and query the priority of the watcher. The priority is a small |
1201 | integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI> |
1205 | integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI> |
… | |
… | |
1232 | returns its C<revents> bitset (as if its callback was invoked). If the |
1236 | returns its C<revents> bitset (as if its callback was invoked). If the |
1233 | watcher isn't pending it does nothing and returns C<0>. |
1237 | watcher isn't pending it does nothing and returns C<0>. |
1234 | |
1238 | |
1235 | Sometimes it can be useful to "poll" a watcher instead of waiting for its |
1239 | Sometimes it can be useful to "poll" a watcher instead of waiting for its |
1236 | callback to be invoked, which can be accomplished with this function. |
1240 | callback to be invoked, which can be accomplished with this function. |
|
|
1241 | |
|
|
1242 | =item ev_feed_event (loop, ev_TYPE *watcher, int revents) |
|
|
1243 | |
|
|
1244 | Feeds the given event set into the event loop, as if the specified event |
|
|
1245 | had happened for the specified watcher (which must be a pointer to an |
|
|
1246 | initialised but not necessarily started event watcher). Obviously you must |
|
|
1247 | not free the watcher as long as it has pending events. |
|
|
1248 | |
|
|
1249 | Stopping the watcher, letting libev invoke it, or calling |
|
|
1250 | C<ev_clear_pending> will clear the pending event, even if the watcher was |
|
|
1251 | not started in the first place. |
|
|
1252 | |
|
|
1253 | See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related |
|
|
1254 | functions that do not need a watcher. |
1237 | |
1255 | |
1238 | =back |
1256 | =back |
1239 | |
1257 | |
1240 | |
1258 | |
1241 | =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER |
1259 | =head2 ASSOCIATING CUSTOM DATA WITH A WATCHER |
… | |
… | |
1837 | C<repeat> value), or reset the running timer to the C<repeat> value. |
1855 | C<repeat> value), or reset the running timer to the C<repeat> value. |
1838 | |
1856 | |
1839 | This sounds a bit complicated, see L<Be smart about timeouts>, above, for a |
1857 | This sounds a bit complicated, see L<Be smart about timeouts>, above, for a |
1840 | usage example. |
1858 | usage example. |
1841 | |
1859 | |
1842 | =item ev_timer_remaining (loop, ev_timer *) |
1860 | =item ev_tstamp ev_timer_remaining (loop, ev_timer *) |
1843 | |
1861 | |
1844 | Returns the remaining time until a timer fires. If the timer is active, |
1862 | Returns the remaining time until a timer fires. If the timer is active, |
1845 | then this time is relative to the current event loop time, otherwise it's |
1863 | then this time is relative to the current event loop time, otherwise it's |
1846 | the timeout value currently configured. |
1864 | the timeout value currently configured. |
1847 | |
1865 | |
… | |
… | |
2136 | to install a fork handler with C<pthread_atfork> that resets it. That will |
2154 | to install a fork handler with C<pthread_atfork> that resets it. That will |
2137 | catch fork calls done by libraries (such as the libc) as well. |
2155 | catch fork calls done by libraries (such as the libc) as well. |
2138 | |
2156 | |
2139 | In current versions of libev, you can also ensure that the signal mask is |
2157 | In current versions of libev, you can also ensure that the signal mask is |
2140 | not blocking any signals (except temporarily, so thread users watch out) |
2158 | not blocking any signals (except temporarily, so thread users watch out) |
2141 | by specifying the C<EVFLAG_NOSIGNALFD> when creating the event loop. This |
2159 | by specifying the C<EVFLAG_NOSIGFD> when creating the event loop. This |
2142 | is not guaranteed for future versions, however. |
2160 | is not guaranteed for future versions, however. |
2143 | |
2161 | |
2144 | =head3 Watcher-Specific Functions and Data Members |
2162 | =head3 Watcher-Specific Functions and Data Members |
2145 | |
2163 | |
2146 | =over 4 |
2164 | =over 4 |
… | |
… | |
2964 | =head3 Queueing |
2982 | =head3 Queueing |
2965 | |
2983 | |
2966 | C<ev_async> does not support queueing of data in any way. The reason |
2984 | C<ev_async> does not support queueing of data in any way. The reason |
2967 | is that the author does not know of a simple (or any) algorithm for a |
2985 | is that the author does not know of a simple (or any) algorithm for a |
2968 | multiple-writer-single-reader queue that works in all cases and doesn't |
2986 | multiple-writer-single-reader queue that works in all cases and doesn't |
2969 | need elaborate support such as pthreads. |
2987 | need elaborate support such as pthreads or unportable memory access |
|
|
2988 | semantics. |
2970 | |
2989 | |
2971 | That means that if you want to queue data, you have to provide your own |
2990 | That means that if you want to queue data, you have to provide your own |
2972 | queue. But at least I can tell you how to implement locking around your |
2991 | queue. But at least I can tell you how to implement locking around your |
2973 | queue: |
2992 | queue: |
2974 | |
2993 | |
… | |
… | |
3132 | /* doh, nothing entered */; |
3151 | /* doh, nothing entered */; |
3133 | } |
3152 | } |
3134 | |
3153 | |
3135 | ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
3154 | ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0); |
3136 | |
3155 | |
3137 | =item ev_feed_event (struct ev_loop *, watcher *, int revents) |
|
|
3138 | |
|
|
3139 | Feeds the given event set into the event loop, as if the specified event |
|
|
3140 | had happened for the specified watcher (which must be a pointer to an |
|
|
3141 | initialised but not necessarily started event watcher). |
|
|
3142 | |
|
|
3143 | =item ev_feed_fd_event (struct ev_loop *, int fd, int revents) |
3156 | =item ev_feed_fd_event (loop, int fd, int revents) |
3144 | |
3157 | |
3145 | Feed an event on the given fd, as if a file descriptor backend detected |
3158 | Feed an event on the given fd, as if a file descriptor backend detected |
3146 | the given events it. |
3159 | the given events it. |
3147 | |
3160 | |
3148 | =item ev_feed_signal_event (struct ev_loop *loop, int signum) |
3161 | =item ev_feed_signal_event (loop, int signum) |
3149 | |
3162 | |
3150 | Feed an event as if the given signal occurred (C<loop> must be the default |
3163 | Feed an event as if the given signal occurred (C<loop> must be the default |
3151 | loop!). |
3164 | loop!). |
3152 | |
3165 | |
3153 | =back |
3166 | =back |
… | |
… | |
3233 | |
3246 | |
3234 | =over 4 |
3247 | =over 4 |
3235 | |
3248 | |
3236 | =item ev::TYPE::TYPE () |
3249 | =item ev::TYPE::TYPE () |
3237 | |
3250 | |
3238 | =item ev::TYPE::TYPE (struct ev_loop *) |
3251 | =item ev::TYPE::TYPE (loop) |
3239 | |
3252 | |
3240 | =item ev::TYPE::~TYPE |
3253 | =item ev::TYPE::~TYPE |
3241 | |
3254 | |
3242 | The constructor (optionally) takes an event loop to associate the watcher |
3255 | The constructor (optionally) takes an event loop to associate the watcher |
3243 | with. If it is omitted, it will use C<EV_DEFAULT>. |
3256 | with. If it is omitted, it will use C<EV_DEFAULT>. |
… | |
… | |
3320 | Example: Use a plain function as callback. |
3333 | Example: Use a plain function as callback. |
3321 | |
3334 | |
3322 | static void io_cb (ev::io &w, int revents) { } |
3335 | static void io_cb (ev::io &w, int revents) { } |
3323 | iow.set <io_cb> (); |
3336 | iow.set <io_cb> (); |
3324 | |
3337 | |
3325 | =item w->set (struct ev_loop *) |
3338 | =item w->set (loop) |
3326 | |
3339 | |
3327 | Associates a different C<struct ev_loop> with this watcher. You can only |
3340 | Associates a different C<struct ev_loop> with this watcher. You can only |
3328 | do this when the watcher is inactive (and not pending either). |
3341 | do this when the watcher is inactive (and not pending either). |
3329 | |
3342 | |
3330 | =item w->set ([arguments]) |
3343 | =item w->set ([arguments]) |