… | |
… | |
480 | unblocking the signals. |
480 | unblocking the signals. |
481 | |
481 | |
482 | It's also required by POSIX in a threaded program, as libev calls |
482 | It's also required by POSIX in a threaded program, as libev calls |
483 | C<sigprocmask>, whose behaviour is officially unspecified. |
483 | C<sigprocmask>, whose behaviour is officially unspecified. |
484 | |
484 | |
485 | This flag's behaviour will become the default in future versions of libev. |
485 | =item C<EVFLAG_NOTIMERFD> |
|
|
486 | |
|
|
487 | When this flag is specified, the libev will avoid using a C<timerfd> to |
|
|
488 | detect time jumps. It will still be able to detect time jumps, but takes |
|
|
489 | longer and has a lower accuracy in doing so, but saves a file descriptor |
|
|
490 | per loop. |
|
|
491 | |
|
|
492 | The current implementation only tries to use a C<timerfd> when the first |
|
|
493 | C<ev_periodic> watcher is started and falls back on other methods if it |
|
|
494 | cannot be created, but this behaviour might change in the future. |
486 | |
495 | |
487 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
496 | =item C<EVBACKEND_SELECT> (value 1, portable select backend) |
488 | |
497 | |
489 | This is your standard select(2) backend. Not I<completely> standard, as |
498 | This is your standard select(2) backend. Not I<completely> standard, as |
490 | libev tries to roll its own fd_set with no limits on the number of fds, |
499 | libev tries to roll its own fd_set with no limits on the number of fds, |
… | |
… | |
950 | - Queue all expired timers. |
959 | - Queue all expired timers. |
951 | - Queue all expired periodics. |
960 | - Queue all expired periodics. |
952 | - Queue all idle watchers with priority higher than that of pending events. |
961 | - Queue all idle watchers with priority higher than that of pending events. |
953 | - Queue all check watchers. |
962 | - Queue all check watchers. |
954 | - Call all queued watchers in reverse order (i.e. check watchers first). |
963 | - Call all queued watchers in reverse order (i.e. check watchers first). |
955 | Signals and child watchers are implemented as I/O watchers, and will |
964 | Signals, async and child watchers are implemented as I/O watchers, and |
956 | be handled here by queueing them when their watcher gets executed. |
965 | will be handled here by queueing them when their watcher gets executed. |
957 | - If ev_break has been called, or EVRUN_ONCE or EVRUN_NOWAIT |
966 | - If ev_break has been called, or EVRUN_ONCE or EVRUN_NOWAIT |
958 | were used, or there are no active watchers, goto FINISH, otherwise |
967 | were used, or there are no active watchers, goto FINISH, otherwise |
959 | continue with step LOOP. |
968 | continue with step LOOP. |
960 | FINISH: |
969 | FINISH: |
961 | - Reset the ev_break status iff it was EVBREAK_ONE. |
970 | - Reset the ev_break status iff it was EVBREAK_ONE. |
… | |
… | |
1209 | with a watcher-specific start function (C<< ev_TYPE_start (loop, watcher |
1218 | with a watcher-specific start function (C<< ev_TYPE_start (loop, watcher |
1210 | *) >>), and you can stop watching for events at any time by calling the |
1219 | *) >>), and you can stop watching for events at any time by calling the |
1211 | corresponding stop function (C<< ev_TYPE_stop (loop, watcher *) >>. |
1220 | corresponding stop function (C<< ev_TYPE_stop (loop, watcher *) >>. |
1212 | |
1221 | |
1213 | As long as your watcher is active (has been started but not stopped) you |
1222 | As long as your watcher is active (has been started but not stopped) you |
1214 | must not touch the values stored in it. Most specifically you must never |
1223 | must not touch the values stored in it except when explicitly documented |
1215 | reinitialise it or call its C<ev_TYPE_set> macro. |
1224 | otherwise. Most specifically you must never reinitialise it or call its |
|
|
1225 | C<ev_TYPE_set> macro. |
1216 | |
1226 | |
1217 | Each and every callback receives the event loop pointer as first, the |
1227 | Each and every callback receives the event loop pointer as first, the |
1218 | registered watcher structure as second, and a bitset of received events as |
1228 | registered watcher structure as second, and a bitset of received events as |
1219 | third argument. |
1229 | third argument. |
1220 | |
1230 | |
… | |
… | |
1386 | |
1396 | |
1387 | =item bool ev_is_active (ev_TYPE *watcher) |
1397 | =item bool ev_is_active (ev_TYPE *watcher) |
1388 | |
1398 | |
1389 | Returns a true value iff the watcher is active (i.e. it has been started |
1399 | Returns a true value iff the watcher is active (i.e. it has been started |
1390 | and not yet been stopped). As long as a watcher is active you must not modify |
1400 | and not yet been stopped). As long as a watcher is active you must not modify |
1391 | it. |
1401 | it unless documented otherwise. |
1392 | |
1402 | |
1393 | =item bool ev_is_pending (ev_TYPE *watcher) |
1403 | =item bool ev_is_pending (ev_TYPE *watcher) |
1394 | |
1404 | |
1395 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
1405 | Returns a true value iff the watcher is pending, (i.e. it has outstanding |
1396 | events but its callback has not yet been invoked). As long as a watcher |
1406 | events but its callback has not yet been invoked). As long as a watcher |
… | |
… | |
1535 | |
1545 | |
1536 | Many event loops support I<watcher priorities>, which are usually small |
1546 | Many event loops support I<watcher priorities>, which are usually small |
1537 | integers that influence the ordering of event callback invocation |
1547 | integers that influence the ordering of event callback invocation |
1538 | between watchers in some way, all else being equal. |
1548 | between watchers in some way, all else being equal. |
1539 | |
1549 | |
1540 | In libev, Watcher priorities can be set using C<ev_set_priority>. See its |
1550 | In libev, watcher priorities can be set using C<ev_set_priority>. See its |
1541 | description for the more technical details such as the actual priority |
1551 | description for the more technical details such as the actual priority |
1542 | range. |
1552 | range. |
1543 | |
1553 | |
1544 | There are two common ways how these these priorities are being interpreted |
1554 | There are two common ways how these these priorities are being interpreted |
1545 | by event loops: |
1555 | by event loops: |
… | |
… | |
1639 | |
1649 | |
1640 | This section describes each watcher in detail, but will not repeat |
1650 | This section describes each watcher in detail, but will not repeat |
1641 | information given in the last section. Any initialisation/set macros, |
1651 | information given in the last section. Any initialisation/set macros, |
1642 | functions and members specific to the watcher type are explained. |
1652 | functions and members specific to the watcher type are explained. |
1643 | |
1653 | |
1644 | Members are additionally marked with either I<[read-only]>, meaning that, |
1654 | Most members are additionally marked with either I<[read-only]>, meaning |
1645 | while the watcher is active, you can look at the member and expect some |
1655 | that, while the watcher is active, you can look at the member and expect |
1646 | sensible content, but you must not modify it (you can modify it while the |
1656 | some sensible content, but you must not modify it (you can modify it while |
1647 | watcher is stopped to your hearts content), or I<[read-write]>, which |
1657 | the watcher is stopped to your hearts content), or I<[read-write]>, which |
1648 | means you can expect it to have some sensible content while the watcher |
1658 | means you can expect it to have some sensible content while the watcher is |
1649 | is active, but you can also modify it. Modifying it may not do something |
1659 | active, but you can also modify it (within the same thread as the event |
|
|
1660 | loop, i.e. without creating data races). Modifying it may not do something |
1650 | sensible or take immediate effect (or do anything at all), but libev will |
1661 | sensible or take immediate effect (or do anything at all), but libev will |
1651 | not crash or malfunction in any way. |
1662 | not crash or malfunction in any way. |
1652 | |
1663 | |
|
|
1664 | In any case, the documentation for each member will explain what the |
|
|
1665 | effects are, and if there are any additional access restrictions. |
1653 | |
1666 | |
1654 | =head2 C<ev_io> - is this file descriptor readable or writable? |
1667 | =head2 C<ev_io> - is this file descriptor readable or writable? |
1655 | |
1668 | |
1656 | I/O watchers check whether a file descriptor is readable or writable |
1669 | I/O watchers check whether a file descriptor is readable or writable |
1657 | in each iteration of the event loop, or, more precisely, when reading |
1670 | in each iteration of the event loop, or, more precisely, when reading |
… | |
… | |
1817 | =item ev_io_init (ev_io *, callback, int fd, int events) |
1830 | =item ev_io_init (ev_io *, callback, int fd, int events) |
1818 | |
1831 | |
1819 | =item ev_io_set (ev_io *, int fd, int events) |
1832 | =item ev_io_set (ev_io *, int fd, int events) |
1820 | |
1833 | |
1821 | Configures an C<ev_io> watcher. The C<fd> is the file descriptor to |
1834 | Configures an C<ev_io> watcher. The C<fd> is the file descriptor to |
1822 | receive events for and C<events> is either C<EV_READ>, C<EV_WRITE> or |
1835 | receive events for and C<events> is either C<EV_READ>, C<EV_WRITE>, both |
1823 | C<EV_READ | EV_WRITE>, to express the desire to receive the given events. |
1836 | C<EV_READ | EV_WRITE> or C<0>, to express the desire to receive the given |
|
|
1837 | events. |
1824 | |
1838 | |
1825 | =item int fd [read-only] |
1839 | Note that setting the C<events> to C<0> and starting the watcher is |
|
|
1840 | supported, but not specially optimized - if your program sometimes happens |
|
|
1841 | to generate this combination this is fine, but if it is easy to avoid |
|
|
1842 | starting an io watcher watching for no events you should do so. |
1826 | |
1843 | |
1827 | The file descriptor being watched. |
1844 | =item ev_io_modify (ev_io *, int events) |
1828 | |
1845 | |
|
|
1846 | Similar to C<ev_io_set>, but only changes the requested events. Using this |
|
|
1847 | might be faster with some backends, as libev can assume that the C<fd> |
|
|
1848 | still refers to the same underlying file description, something it cannot |
|
|
1849 | do when using C<ev_io_set>. |
|
|
1850 | |
|
|
1851 | =item int fd [no-modify] |
|
|
1852 | |
|
|
1853 | The file descriptor being watched. While it can be read at any time, you |
|
|
1854 | must not modify this member even when the watcher is stopped - always use |
|
|
1855 | C<ev_io_set> for that. |
|
|
1856 | |
1829 | =item int events [read-only] |
1857 | =item int events [no-modify] |
1830 | |
1858 | |
1831 | The events being watched. |
1859 | The set of events the fd is being watched for, among other flags. Remember |
|
|
1860 | that this is a bit set - to test for C<EV_READ>, use C<< w->events & |
|
|
1861 | EV_READ >>, and similarly for C<EV_WRITE>. |
|
|
1862 | |
|
|
1863 | As with C<fd>, you must not modify this member even when the watcher is |
|
|
1864 | stopped, always use C<ev_io_set> or C<ev_io_modify> for that. |
1832 | |
1865 | |
1833 | =back |
1866 | =back |
1834 | |
1867 | |
1835 | =head3 Examples |
1868 | =head3 Examples |
1836 | |
1869 | |
… | |
… | |
3829 | event loop thread and an unspecified mechanism to wake up the main thread. |
3862 | event loop thread and an unspecified mechanism to wake up the main thread. |
3830 | |
3863 | |
3831 | First, you need to associate some data with the event loop: |
3864 | First, you need to associate some data with the event loop: |
3832 | |
3865 | |
3833 | typedef struct { |
3866 | typedef struct { |
3834 | mutex_t lock; /* global loop lock */ |
3867 | pthread_mutex_t lock; /* global loop lock */ |
|
|
3868 | pthread_t tid; |
|
|
3869 | pthread_cond_t invoke_cv; |
3835 | ev_async async_w; |
3870 | ev_async async_w; |
3836 | thread_t tid; |
|
|
3837 | cond_t invoke_cv; |
|
|
3838 | } userdata; |
3871 | } userdata; |
3839 | |
3872 | |
3840 | void prepare_loop (EV_P) |
3873 | void prepare_loop (EV_P) |
3841 | { |
3874 | { |
3842 | // for simplicity, we use a static userdata struct. |
3875 | // for simplicity, we use a static userdata struct. |
3843 | static userdata u; |
3876 | static userdata u; |
3844 | |
3877 | |
3845 | ev_async_init (&u->async_w, async_cb); |
3878 | ev_async_init (&u.async_w, async_cb); |
3846 | ev_async_start (EV_A_ &u->async_w); |
3879 | ev_async_start (EV_A_ &u.async_w); |
3847 | |
3880 | |
3848 | pthread_mutex_init (&u->lock, 0); |
3881 | pthread_mutex_init (&u.lock, 0); |
3849 | pthread_cond_init (&u->invoke_cv, 0); |
3882 | pthread_cond_init (&u.invoke_cv, 0); |
3850 | |
3883 | |
3851 | // now associate this with the loop |
3884 | // now associate this with the loop |
3852 | ev_set_userdata (EV_A_ u); |
3885 | ev_set_userdata (EV_A_ &u); |
3853 | ev_set_invoke_pending_cb (EV_A_ l_invoke); |
3886 | ev_set_invoke_pending_cb (EV_A_ l_invoke); |
3854 | ev_set_loop_release_cb (EV_A_ l_release, l_acquire); |
3887 | ev_set_loop_release_cb (EV_A_ l_release, l_acquire); |
3855 | |
3888 | |
3856 | // then create the thread running ev_run |
3889 | // then create the thread running ev_run |
3857 | pthread_create (&u->tid, 0, l_run, EV_A); |
3890 | pthread_create (&u.tid, 0, l_run, EV_A); |
3858 | } |
3891 | } |
3859 | |
3892 | |
3860 | The callback for the C<ev_async> watcher does nothing: the watcher is used |
3893 | The callback for the C<ev_async> watcher does nothing: the watcher is used |
3861 | solely to wake up the event loop so it takes notice of any new watchers |
3894 | solely to wake up the event loop so it takes notice of any new watchers |
3862 | that might have been added: |
3895 | that might have been added: |
… | |
… | |
4233 | gets automatically stopped and restarted when reconfiguring it with this |
4266 | gets automatically stopped and restarted when reconfiguring it with this |
4234 | method. |
4267 | method. |
4235 | |
4268 | |
4236 | For C<ev::embed> watchers this method is called C<set_embed>, to avoid |
4269 | For C<ev::embed> watchers this method is called C<set_embed>, to avoid |
4237 | clashing with the C<set (loop)> method. |
4270 | clashing with the C<set (loop)> method. |
|
|
4271 | |
|
|
4272 | For C<ev::io> watchers there is an additional C<set> method that acepts a |
|
|
4273 | new event mask only, and internally calls C<ev_io_modfify>. |
4238 | |
4274 | |
4239 | =item w->start () |
4275 | =item w->start () |
4240 | |
4276 | |
4241 | Starts the watcher. Note that there is no C<loop> argument, as the |
4277 | Starts the watcher. Note that there is no C<loop> argument, as the |
4242 | constructor already stores the event loop. |
4278 | constructor already stores the event loop. |
… | |
… | |
4606 | |
4642 | |
4607 | =item EV_USE_NANOSLEEP |
4643 | =item EV_USE_NANOSLEEP |
4608 | |
4644 | |
4609 | If defined to be C<1>, libev will assume that C<nanosleep ()> is available |
4645 | If defined to be C<1>, libev will assume that C<nanosleep ()> is available |
4610 | and will use it for delays. Otherwise it will use C<select ()>. |
4646 | and will use it for delays. Otherwise it will use C<select ()>. |
|
|
4647 | |
|
|
4648 | =item EV_USE_EVENTFD |
|
|
4649 | |
|
|
4650 | If defined to be C<1>, then libev will assume that C<eventfd ()> is |
|
|
4651 | available and will probe for kernel support at runtime. This will improve |
|
|
4652 | C<ev_signal> and C<ev_async> performance and reduce resource consumption. |
|
|
4653 | If undefined, it will be enabled if the headers indicate GNU/Linux + Glibc |
|
|
4654 | 2.7 or newer, otherwise disabled. |
|
|
4655 | |
|
|
4656 | =item EV_USE_SIGNALFD |
|
|
4657 | |
|
|
4658 | If defined to be C<1>, then libev will assume that C<signalfd ()> is |
|
|
4659 | available and will probe for kernel support at runtime. This enables |
|
|
4660 | the use of EVFLAG_SIGNALFD for faster and simpler signal handling. If |
|
|
4661 | undefined, it will be enabled if the headers indicate GNU/Linux + Glibc |
|
|
4662 | 2.7 or newer, otherwise disabled. |
|
|
4663 | |
|
|
4664 | =item EV_USE_TIMERFD |
|
|
4665 | |
|
|
4666 | If defined to be C<1>, then libev will assume that C<timerfd ()> is |
|
|
4667 | available and will probe for kernel support at runtime. This allows |
|
|
4668 | libev to detect time jumps accurately. If undefined, it will be enabled |
|
|
4669 | if the headers indicate GNU/Linux + Glibc 2.8 or newer and define |
|
|
4670 | C<TFD_TIMER_CANCEL_ON_SET>, otherwise disabled. |
4611 | |
4671 | |
4612 | =item EV_USE_EVENTFD |
4672 | =item EV_USE_EVENTFD |
4613 | |
4673 | |
4614 | If defined to be C<1>, then libev will assume that C<eventfd ()> is |
4674 | If defined to be C<1>, then libev will assume that C<eventfd ()> is |
4615 | available and will probe for kernel support at runtime. This will improve |
4675 | available and will probe for kernel support at runtime. This will improve |