… | |
… | |
82 | |
82 | |
83 | =head1 WHAT TO READ WHEN IN A HURRY |
83 | =head1 WHAT TO READ WHEN IN A HURRY |
84 | |
84 | |
85 | This manual tries to be very detailed, but unfortunately, this also makes |
85 | This manual tries to be very detailed, but unfortunately, this also makes |
86 | it very long. If you just want to know the basics of libev, I suggest |
86 | it very long. If you just want to know the basics of libev, I suggest |
87 | reading L<ANATOMY OF A WATCHER>, then the L<EXAMPLE PROGRAM> above and |
87 | reading L</ANATOMY OF A WATCHER>, then the L</EXAMPLE PROGRAM> above and |
88 | look up the missing functions in L<GLOBAL FUNCTIONS> and the C<ev_io> and |
88 | look up the missing functions in L</GLOBAL FUNCTIONS> and the C<ev_io> and |
89 | C<ev_timer> sections in L<WATCHER TYPES>. |
89 | C<ev_timer> sections in L</WATCHER TYPES>. |
90 | |
90 | |
91 | =head1 ABOUT LIBEV |
91 | =head1 ABOUT LIBEV |
92 | |
92 | |
93 | Libev is an event loop: you register interest in certain events (such as a |
93 | Libev is an event loop: you register interest in certain events (such as a |
94 | file descriptor being readable or a timeout occurring), and it will manage |
94 | file descriptor being readable or a timeout occurring), and it will manage |
… | |
… | |
764 | |
764 | |
765 | This function is rarely useful, but when some event callback runs for a |
765 | This function is rarely useful, but when some event callback runs for a |
766 | very long time without entering the event loop, updating libev's idea of |
766 | very long time without entering the event loop, updating libev's idea of |
767 | the current time is a good idea. |
767 | the current time is a good idea. |
768 | |
768 | |
769 | See also L<The special problem of time updates> in the C<ev_timer> section. |
769 | See also L</The special problem of time updates> in the C<ev_timer> section. |
770 | |
770 | |
771 | =item ev_suspend (loop) |
771 | =item ev_suspend (loop) |
772 | |
772 | |
773 | =item ev_resume (loop) |
773 | =item ev_resume (loop) |
774 | |
774 | |
… | |
… | |
1318 | |
1318 | |
1319 | =item callback ev_cb (ev_TYPE *watcher) |
1319 | =item callback ev_cb (ev_TYPE *watcher) |
1320 | |
1320 | |
1321 | Returns the callback currently set on the watcher. |
1321 | Returns the callback currently set on the watcher. |
1322 | |
1322 | |
1323 | =item ev_cb_set (ev_TYPE *watcher, callback) |
1323 | =item ev_set_cb (ev_TYPE *watcher, callback) |
1324 | |
1324 | |
1325 | Change the callback. You can change the callback at virtually any time |
1325 | Change the callback. You can change the callback at virtually any time |
1326 | (modulo threads). |
1326 | (modulo threads). |
1327 | |
1327 | |
1328 | =item ev_set_priority (ev_TYPE *watcher, int priority) |
1328 | =item ev_set_priority (ev_TYPE *watcher, int priority) |
… | |
… | |
1346 | or might not have been clamped to the valid range. |
1346 | or might not have been clamped to the valid range. |
1347 | |
1347 | |
1348 | The default priority used by watchers when no priority has been set is |
1348 | The default priority used by watchers when no priority has been set is |
1349 | always C<0>, which is supposed to not be too high and not be too low :). |
1349 | always C<0>, which is supposed to not be too high and not be too low :). |
1350 | |
1350 | |
1351 | See L<WATCHER PRIORITY MODELS>, below, for a more thorough treatment of |
1351 | See L</WATCHER PRIORITY MODELS>, below, for a more thorough treatment of |
1352 | priorities. |
1352 | priorities. |
1353 | |
1353 | |
1354 | =item ev_invoke (loop, ev_TYPE *watcher, int revents) |
1354 | =item ev_invoke (loop, ev_TYPE *watcher, int revents) |
1355 | |
1355 | |
1356 | Invoke the C<watcher> with the given C<loop> and C<revents>. Neither |
1356 | Invoke the C<watcher> with the given C<loop> and C<revents>. Neither |
… | |
… | |
1381 | See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related |
1381 | See also C<ev_feed_fd_event> and C<ev_feed_signal_event> for related |
1382 | functions that do not need a watcher. |
1382 | functions that do not need a watcher. |
1383 | |
1383 | |
1384 | =back |
1384 | =back |
1385 | |
1385 | |
1386 | See also the L<ASSOCIATING CUSTOM DATA WITH A WATCHER> and L<BUILDING YOUR |
1386 | See also the L</ASSOCIATING CUSTOM DATA WITH A WATCHER> and L</BUILDING YOUR |
1387 | OWN COMPOSITE WATCHERS> idioms. |
1387 | OWN COMPOSITE WATCHERS> idioms. |
1388 | |
1388 | |
1389 | =head2 WATCHER STATES |
1389 | =head2 WATCHER STATES |
1390 | |
1390 | |
1391 | There are various watcher states mentioned throughout this manual - |
1391 | There are various watcher states mentioned throughout this manual - |
… | |
… | |
2136 | =item If the timer is repeating, make the C<repeat> value the new timeout |
2136 | =item If the timer is repeating, make the C<repeat> value the new timeout |
2137 | and start the timer, if necessary. |
2137 | and start the timer, if necessary. |
2138 | |
2138 | |
2139 | =back |
2139 | =back |
2140 | |
2140 | |
2141 | This sounds a bit complicated, see L<Be smart about timeouts>, above, for a |
2141 | This sounds a bit complicated, see L</Be smart about timeouts>, above, for a |
2142 | usage example. |
2142 | usage example. |
2143 | |
2143 | |
2144 | =item ev_tstamp ev_timer_remaining (loop, ev_timer *) |
2144 | =item ev_tstamp ev_timer_remaining (loop, ev_timer *) |
2145 | |
2145 | |
2146 | Returns the remaining time until a timer fires. If the timer is active, |
2146 | Returns the remaining time until a timer fires. If the timer is active, |
… | |
… | |
2858 | |
2858 | |
2859 | This mode of operation can be useful together with an C<ev_check> watcher, |
2859 | This mode of operation can be useful together with an C<ev_check> watcher, |
2860 | to do something on each event loop iteration - for example to balance load |
2860 | to do something on each event loop iteration - for example to balance load |
2861 | between different connections. |
2861 | between different connections. |
2862 | |
2862 | |
2863 | See L<Abusing an C<ev_check> watcher for its side-effect> for a longer |
2863 | See L</Abusing an ev_check watcher for its side-effect> for a longer |
2864 | example. |
2864 | example. |
2865 | |
2865 | |
2866 | =head3 Watcher-Specific Functions and Data Members |
2866 | =head3 Watcher-Specific Functions and Data Members |
2867 | |
2867 | |
2868 | =over 4 |
2868 | =over 4 |
… | |
… | |
3875 | called): |
3875 | called): |
3876 | |
3876 | |
3877 | void |
3877 | void |
3878 | wait_for_event (ev_watcher *w) |
3878 | wait_for_event (ev_watcher *w) |
3879 | { |
3879 | { |
3880 | ev_cb_set (w) = current_coro; |
3880 | ev_set_cb (w, current_coro); |
3881 | switch_to (libev_coro); |
3881 | switch_to (libev_coro); |
3882 | } |
3882 | } |
3883 | |
3883 | |
3884 | That basically suspends the coroutine inside C<wait_for_event> and |
3884 | That basically suspends the coroutine inside C<wait_for_event> and |
3885 | continues the libev coroutine, which, when appropriate, switches back to |
3885 | continues the libev coroutine, which, when appropriate, switches back to |
… | |
… | |
3888 | You can do similar tricks if you have, say, threads with an event queue - |
3888 | You can do similar tricks if you have, say, threads with an event queue - |
3889 | instead of storing a coroutine, you store the queue object and instead of |
3889 | instead of storing a coroutine, you store the queue object and instead of |
3890 | switching to a coroutine, you push the watcher onto the queue and notify |
3890 | switching to a coroutine, you push the watcher onto the queue and notify |
3891 | any waiters. |
3891 | any waiters. |
3892 | |
3892 | |
3893 | To embed libev, see L<EMBEDDING>, but in short, it's easiest to create two |
3893 | To embed libev, see L</EMBEDDING>, but in short, it's easiest to create two |
3894 | files, F<my_ev.h> and F<my_ev.c> that include the respective libev files: |
3894 | files, F<my_ev.h> and F<my_ev.c> that include the respective libev files: |
3895 | |
3895 | |
3896 | // my_ev.h |
3896 | // my_ev.h |
3897 | #define EV_CB_DECLARE(type) struct my_coro *cb; |
3897 | #define EV_CB_DECLARE(type) struct my_coro *cb; |
3898 | #define EV_CB_INVOKE(watcher) switch_to ((watcher)->cb); |
3898 | #define EV_CB_INVOKE(watcher) switch_to ((watcher)->cb); |
… | |
… | |
4238 | |
4238 | |
4239 | Brian Maher has written a partial interface to libev for lua (at the |
4239 | Brian Maher has written a partial interface to libev for lua (at the |
4240 | time of this writing, only C<ev_io> and C<ev_timer>), to be found at |
4240 | time of this writing, only C<ev_io> and C<ev_timer>), to be found at |
4241 | L<http://github.com/brimworks/lua-ev>. |
4241 | L<http://github.com/brimworks/lua-ev>. |
4242 | |
4242 | |
|
|
4243 | =item Javascript |
|
|
4244 | |
|
|
4245 | Node.js (L<http://nodejs.org>) uses libev as the underlying event library. |
|
|
4246 | |
|
|
4247 | =item Others |
|
|
4248 | |
|
|
4249 | There are others, and I stopped counting. |
|
|
4250 | |
4243 | =back |
4251 | =back |
4244 | |
4252 | |
4245 | |
4253 | |
4246 | =head1 MACRO MAGIC |
4254 | =head1 MACRO MAGIC |
4247 | |
4255 | |
… | |
… | |
4993 | default loop and triggering an C<ev_async> watcher from the default loop |
5001 | default loop and triggering an C<ev_async> watcher from the default loop |
4994 | watcher callback into the event loop interested in the signal. |
5002 | watcher callback into the event loop interested in the signal. |
4995 | |
5003 | |
4996 | =back |
5004 | =back |
4997 | |
5005 | |
4998 | See also L<THREAD LOCKING EXAMPLE>. |
5006 | See also L</THREAD LOCKING EXAMPLE>. |
4999 | |
5007 | |
5000 | =head3 COROUTINES |
5008 | =head3 COROUTINES |
5001 | |
5009 | |
5002 | Libev is very accommodating to coroutines ("cooperative threads"): |
5010 | Libev is very accommodating to coroutines ("cooperative threads"): |
5003 | libev fully supports nesting calls to its functions from different |
5011 | libev fully supports nesting calls to its functions from different |
… | |
… | |
5409 | =over 4 |
5417 | =over 4 |
5410 | |
5418 | |
5411 | =item C<EV_COMPAT3> backwards compatibility mechanism |
5419 | =item C<EV_COMPAT3> backwards compatibility mechanism |
5412 | |
5420 | |
5413 | The backward compatibility mechanism can be controlled by |
5421 | The backward compatibility mechanism can be controlled by |
5414 | C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING> |
5422 | C<EV_COMPAT3>. See L</PREPROCESSOR SYMBOLS/MACROS> in the L</EMBEDDING> |
5415 | section. |
5423 | section. |
5416 | |
5424 | |
5417 | =item C<ev_default_destroy> and C<ev_default_fork> have been removed |
5425 | =item C<ev_default_destroy> and C<ev_default_fork> have been removed |
5418 | |
5426 | |
5419 | These calls can be replaced easily by their C<ev_loop_xxx> counterparts: |
5427 | These calls can be replaced easily by their C<ev_loop_xxx> counterparts: |
… | |
… | |
5462 | =over 4 |
5470 | =over 4 |
5463 | |
5471 | |
5464 | =item active |
5472 | =item active |
5465 | |
5473 | |
5466 | A watcher is active as long as it has been started and not yet stopped. |
5474 | A watcher is active as long as it has been started and not yet stopped. |
5467 | See L<WATCHER STATES> for details. |
5475 | See L</WATCHER STATES> for details. |
5468 | |
5476 | |
5469 | =item application |
5477 | =item application |
5470 | |
5478 | |
5471 | In this document, an application is whatever is using libev. |
5479 | In this document, an application is whatever is using libev. |
5472 | |
5480 | |
… | |
… | |
5508 | watchers and events. |
5516 | watchers and events. |
5509 | |
5517 | |
5510 | =item pending |
5518 | =item pending |
5511 | |
5519 | |
5512 | A watcher is pending as soon as the corresponding event has been |
5520 | A watcher is pending as soon as the corresponding event has been |
5513 | detected. See L<WATCHER STATES> for details. |
5521 | detected. See L</WATCHER STATES> for details. |
5514 | |
5522 | |
5515 | =item real time |
5523 | =item real time |
5516 | |
5524 | |
5517 | The physical time that is observed. It is apparently strictly monotonic :) |
5525 | The physical time that is observed. It is apparently strictly monotonic :) |
5518 | |
5526 | |