… | |
… | |
58 | ev_timer_start (loop, &timeout_watcher); |
58 | ev_timer_start (loop, &timeout_watcher); |
59 | |
59 | |
60 | // now wait for events to arrive |
60 | // now wait for events to arrive |
61 | ev_run (loop, 0); |
61 | ev_run (loop, 0); |
62 | |
62 | |
63 | // unloop was called, so exit |
63 | // break was called, so exit |
64 | return 0; |
64 | return 0; |
65 | } |
65 | } |
66 | |
66 | |
67 | =head1 ABOUT THIS DOCUMENT |
67 | =head1 ABOUT THIS DOCUMENT |
68 | |
68 | |
… | |
… | |
441 | when you want to receive them. |
441 | when you want to receive them. |
442 | |
442 | |
443 | This behaviour is useful when you want to do your own signal handling, or |
443 | This behaviour is useful when you want to do your own signal handling, or |
444 | want to handle signals only in specific threads and want to avoid libev |
444 | want to handle signals only in specific threads and want to avoid libev |
445 | unblocking the signals. |
445 | unblocking the signals. |
|
|
446 | |
|
|
447 | It's also required by POSIX in a threaded program, as libev calls |
|
|
448 | C<sigprocmask>, whose behaviour is officially unspecified. |
446 | |
449 | |
447 | This flag's behaviour will become the default in future versions of libev. |
450 | This flag's behaviour will become the default in future versions of libev. |
448 | |
451 | |
449 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
452 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
450 | |
453 | |
… | |
… | |
865 | anymore. |
868 | anymore. |
866 | |
869 | |
867 | ... queue jobs here, make sure they register event watchers as long |
870 | ... queue jobs here, make sure they register event watchers as long |
868 | ... as they still have work to do (even an idle watcher will do..) |
871 | ... as they still have work to do (even an idle watcher will do..) |
869 | ev_run (my_loop, 0); |
872 | ev_run (my_loop, 0); |
870 | ... jobs done or somebody called unloop. yeah! |
873 | ... jobs done or somebody called break. yeah! |
871 | |
874 | |
872 | =item ev_break (loop, how) |
875 | =item ev_break (loop, how) |
873 | |
876 | |
874 | Can be used to make a call to C<ev_run> return early (but only after it |
877 | Can be used to make a call to C<ev_run> return early (but only after it |
875 | has processed all outstanding events). The C<how> argument must be either |
878 | has processed all outstanding events). The C<how> argument must be either |
… | |
… | |
1375 | |
1378 | |
1376 | Before a watcher can be registered with the event looop it has to be |
1379 | Before a watcher can be registered with the event looop it has to be |
1377 | initialised. This can be done with a call to C<ev_TYPE_init>, or calls to |
1380 | initialised. This can be done with a call to C<ev_TYPE_init>, or calls to |
1378 | C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function. |
1381 | C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function. |
1379 | |
1382 | |
1380 | In this state it is simply some block of memory that is suitable for use |
1383 | In this state it is simply some block of memory that is suitable for |
1381 | in an event loop. It can be moved around, freed, reused etc. at will. |
1384 | use in an event loop. It can be moved around, freed, reused etc. at |
|
|
1385 | will - as long as you either keep the memory contents intact, or call |
|
|
1386 | C<ev_TYPE_init> again. |
1382 | |
1387 | |
1383 | =item started/running/active |
1388 | =item started/running/active |
1384 | |
1389 | |
1385 | Once a watcher has been started with a call to C<ev_TYPE_start> it becomes |
1390 | Once a watcher has been started with a call to C<ev_TYPE_start> it becomes |
1386 | property of the event loop, and is actively waiting for events. While in |
1391 | property of the event loop, and is actively waiting for events. While in |
… | |
… | |
1414 | latter will clear any pending state the watcher might be in, regardless |
1419 | latter will clear any pending state the watcher might be in, regardless |
1415 | of whether it was active or not, so stopping a watcher explicitly before |
1420 | of whether it was active or not, so stopping a watcher explicitly before |
1416 | freeing it is often a good idea. |
1421 | freeing it is often a good idea. |
1417 | |
1422 | |
1418 | While stopped (and not pending) the watcher is essentially in the |
1423 | While stopped (and not pending) the watcher is essentially in the |
1419 | initialised state, that is it can be reused, moved, modified in any way |
1424 | initialised state, that is, it can be reused, moved, modified in any way |
1420 | you wish. |
1425 | you wish (but when you trash the memory block, you need to C<ev_TYPE_init> |
|
|
1426 | it again). |
1421 | |
1427 | |
1422 | =back |
1428 | =back |
1423 | |
1429 | |
1424 | =head2 WATCHER PRIORITY MODELS |
1430 | =head2 WATCHER PRIORITY MODELS |
1425 | |
1431 | |
… | |
… | |
2300 | =head3 The special problem of inheritance over fork/execve/pthread_create |
2306 | =head3 The special problem of inheritance over fork/execve/pthread_create |
2301 | |
2307 | |
2302 | Both the signal mask (C<sigprocmask>) and the signal disposition |
2308 | Both the signal mask (C<sigprocmask>) and the signal disposition |
2303 | (C<sigaction>) are unspecified after starting a signal watcher (and after |
2309 | (C<sigaction>) are unspecified after starting a signal watcher (and after |
2304 | stopping it again), that is, libev might or might not block the signal, |
2310 | stopping it again), that is, libev might or might not block the signal, |
2305 | and might or might not set or restore the installed signal handler. |
2311 | and might or might not set or restore the installed signal handler (but |
|
|
2312 | see C<EVFLAG_NOSIGMASK>). |
2306 | |
2313 | |
2307 | While this does not matter for the signal disposition (libev never |
2314 | While this does not matter for the signal disposition (libev never |
2308 | sets signals to C<SIG_IGN>, so handlers will be reset to C<SIG_DFL> on |
2315 | sets signals to C<SIG_IGN>, so handlers will be reset to C<SIG_DFL> on |
2309 | C<execve>), this matters for the signal mask: many programs do not expect |
2316 | C<execve>), this matters for the signal mask: many programs do not expect |
2310 | certain signals to be blocked. |
2317 | certain signals to be blocked. |
… | |
… | |
3181 | atexit (program_exits); |
3188 | atexit (program_exits); |
3182 | |
3189 | |
3183 | |
3190 | |
3184 | =head2 C<ev_async> - how to wake up an event loop |
3191 | =head2 C<ev_async> - how to wake up an event loop |
3185 | |
3192 | |
3186 | In general, you cannot use an C<ev_run> from multiple threads or other |
3193 | In general, you cannot use an C<ev_loop> from multiple threads or other |
3187 | asynchronous sources such as signal handlers (as opposed to multiple event |
3194 | asynchronous sources such as signal handlers (as opposed to multiple event |
3188 | loops - those are of course safe to use in different threads). |
3195 | loops - those are of course safe to use in different threads). |
3189 | |
3196 | |
3190 | Sometimes, however, you need to wake up an event loop you do not control, |
3197 | Sometimes, however, you need to wake up an event loop you do not control, |
3191 | for example because it belongs to another thread. This is what C<ev_async> |
3198 | for example because it belongs to another thread. This is what C<ev_async> |
… | |
… | |
3301 | trust me. |
3308 | trust me. |
3302 | |
3309 | |
3303 | =item ev_async_send (loop, ev_async *) |
3310 | =item ev_async_send (loop, ev_async *) |
3304 | |
3311 | |
3305 | Sends/signals/activates the given C<ev_async> watcher, that is, feeds |
3312 | Sends/signals/activates the given C<ev_async> watcher, that is, feeds |
3306 | an C<EV_ASYNC> event on the watcher into the event loop. Unlike |
3313 | an C<EV_ASYNC> event on the watcher into the event loop, and instantly |
|
|
3314 | returns. |
|
|
3315 | |
3307 | C<ev_feed_event>, this call is safe to do from other threads, signal or |
3316 | Unlike C<ev_feed_event>, this call is safe to do from other threads, |
3308 | similar contexts (see the discussion of C<EV_ATOMIC_T> in the embedding |
3317 | signal or similar contexts (see the discussion of C<EV_ATOMIC_T> in the |
3309 | section below on what exactly this means). |
3318 | embedding section below on what exactly this means). |
3310 | |
3319 | |
3311 | Note that, as with other watchers in libev, multiple events might get |
3320 | Note that, as with other watchers in libev, multiple events might get |
3312 | compressed into a single callback invocation (another way to look at this |
3321 | compressed into a single callback invocation (another way to look at this |
3313 | is that C<ev_async> watchers are level-triggered, set on C<ev_async_send>, |
3322 | is that C<ev_async> watchers are level-triggered, set on C<ev_async_send>, |
3314 | reset when the event loop detects that). |
3323 | reset when the event loop detects that). |
… | |
… | |
3540 | // now associate this with the loop |
3549 | // now associate this with the loop |
3541 | ev_set_userdata (EV_A_ u); |
3550 | ev_set_userdata (EV_A_ u); |
3542 | ev_set_invoke_pending_cb (EV_A_ l_invoke); |
3551 | ev_set_invoke_pending_cb (EV_A_ l_invoke); |
3543 | ev_set_loop_release_cb (EV_A_ l_release, l_acquire); |
3552 | ev_set_loop_release_cb (EV_A_ l_release, l_acquire); |
3544 | |
3553 | |
3545 | // then create the thread running ev_loop |
3554 | // then create the thread running ev_run |
3546 | pthread_create (&u->tid, 0, l_run, EV_A); |
3555 | pthread_create (&u->tid, 0, l_run, EV_A); |
3547 | } |
3556 | } |
3548 | |
3557 | |
3549 | The callback for the C<ev_async> watcher does nothing: the watcher is used |
3558 | The callback for the C<ev_async> watcher does nothing: the watcher is used |
3550 | solely to wake up the event loop so it takes notice of any new watchers |
3559 | solely to wake up the event loop so it takes notice of any new watchers |
… | |
… | |
5215 | The physical time that is observed. It is apparently strictly monotonic :) |
5224 | The physical time that is observed. It is apparently strictly monotonic :) |
5216 | |
5225 | |
5217 | =item wall-clock time |
5226 | =item wall-clock time |
5218 | |
5227 | |
5219 | The time and date as shown on clocks. Unlike real time, it can actually |
5228 | The time and date as shown on clocks. Unlike real time, it can actually |
5220 | be wrong and jump forwards and backwards, e.g. when the you adjust your |
5229 | be wrong and jump forwards and backwards, e.g. when you adjust your |
5221 | clock. |
5230 | clock. |
5222 | |
5231 | |
5223 | =item watcher |
5232 | =item watcher |
5224 | |
5233 | |
5225 | A data structure that describes interest in certain events. Watchers need |
5234 | A data structure that describes interest in certain events. Watchers need |
… | |
… | |
5228 | =back |
5237 | =back |
5229 | |
5238 | |
5230 | =head1 AUTHOR |
5239 | =head1 AUTHOR |
5231 | |
5240 | |
5232 | Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael |
5241 | Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael |
5233 | Magnusson and Emanuele Giaquinta. |
5242 | Magnusson and Emanuele Giaquinta, and minor corrections by many others. |
5234 | |
5243 | |