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Comparing libev/ev.pod (file contents):
Revision 1.458 by root, Fri Dec 20 20:51:46 2019 UTC vs.
Revision 1.465 by root, Sun Mar 22 15:13:17 2020 UTC

… …
1218with a watcher-specific start function (C<< ev_TYPE_start (loop, watcher 1218with a watcher-specific start function (C<< ev_TYPE_start (loop, watcher
1219*) >>), 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
1220corresponding stop function (C<< ev_TYPE_stop (loop, watcher *) >>. 1220corresponding stop function (C<< ev_TYPE_stop (loop, watcher *) >>.
1221 1221
1222As long as your watcher is active (has been started but not stopped) you 1222As long as your watcher is active (has been started but not stopped) you
1223must not touch the values stored in it. Most specifically you must never 1223must not touch the values stored in it except when explicitly documented
1224reinitialise it or call its C<ev_TYPE_set> macro. 1224otherwise. Most specifically you must never reinitialise it or call its
1225C<ev_TYPE_set> macro.
1225 1226
1226Each and every callback receives the event loop pointer as first, the 1227Each and every callback receives the event loop pointer as first, the
1227registered watcher structure as second, and a bitset of received events as 1228registered watcher structure as second, and a bitset of received events as
1228third argument. 1229third argument.
1229 1230
… …
1395 1396
1396=item bool ev_is_active (ev_TYPE *watcher) 1397=item bool ev_is_active (ev_TYPE *watcher)
1397 1398
1398Returns a true value iff the watcher is active (i.e. it has been started 1399Returns a true value iff the watcher is active (i.e. it has been started
1399and not yet been stopped). As long as a watcher is active you must not modify 1400and not yet been stopped). As long as a watcher is active you must not modify
1400it. 1401it unless documented otherwise.
1401 1402
1402=item bool ev_is_pending (ev_TYPE *watcher) 1403=item bool ev_is_pending (ev_TYPE *watcher)
1403 1404
1404Returns a true value iff the watcher is pending, (i.e. it has outstanding 1405Returns a true value iff the watcher is pending, (i.e. it has outstanding
1405events but its callback has not yet been invoked). As long as a watcher 1406events but its callback has not yet been invoked). As long as a watcher
… …
1648 1649
1649This section describes each watcher in detail, but will not repeat 1650This section describes each watcher in detail, but will not repeat
1650information given in the last section. Any initialisation/set macros, 1651information given in the last section. Any initialisation/set macros,
1651functions and members specific to the watcher type are explained. 1652functions and members specific to the watcher type are explained.
1652 1653
1653Members are additionally marked with either I<[read-only]>, meaning that, 1654Most members are additionally marked with either I<[read-only]>, meaning
1654while the watcher is active, you can look at the member and expect some 1655that, while the watcher is active, you can look at the member and expect
1655sensible content, but you must not modify it (you can modify it while the 1656some sensible content, but you must not modify it (you can modify it while
1656watcher is stopped to your hearts content), or I<[read-write]>, which 1657the watcher is stopped to your hearts content), or I<[read-write]>, which
1657means you can expect it to have some sensible content while the watcher 1658means you can expect it to have some sensible content while the watcher is
1658is active, but you can also modify it. Modifying it may not do something 1659active, but you can also modify it (within the same thread as the event
1660loop, i.e. without creating data races). Modifying it may not do something
1659sensible or take immediate effect (or do anything at all), but libev will 1661sensible or take immediate effect (or do anything at all), but libev will
1660not crash or malfunction in any way. 1662not crash or malfunction in any way.
1661 1663
1664In any case, the documentation for each member will explain what the
1665effects are, and if there are any additional access restrictions.
1662 1666
1663=head2 C<ev_io> - is this file descriptor readable or writable? 1667=head2 C<ev_io> - is this file descriptor readable or writable?
1664 1668
1665I/O watchers check whether a file descriptor is readable or writable 1669I/O watchers check whether a file descriptor is readable or writable
1666in each iteration of the event loop, or, more precisely, when reading 1670in each iteration of the event loop, or, more precisely, when reading
… …
1826=item ev_io_init (ev_io *, callback, int fd, int events) 1830=item ev_io_init (ev_io *, callback, int fd, int events)
1827 1831
1828=item ev_io_set (ev_io *, int fd, int events) 1832=item ev_io_set (ev_io *, int fd, int events)
1829 1833
1830Configures an C<ev_io> watcher. The C<fd> is the file descriptor to 1834Configures an C<ev_io> watcher. The C<fd> is the file descriptor to
1831receive events for and C<events> is either C<EV_READ>, C<EV_WRITE> or 1835receive events for and C<events> is either C<EV_READ>, C<EV_WRITE>, both
1832C<EV_READ | EV_WRITE>, to express the desire to receive the given events. 1836C<EV_READ | EV_WRITE> or C<0>, to express the desire to receive the given
1837events.
1833 1838
1834=item int fd [read-only] 1839Note that setting the C<events> to C<0> and starting the watcher is
1840supported, but not specially optimized - if your program sometimes happens
1841to generate this combination this is fine, but if it is easy to avoid
1842starting an io watcher watching for no events you should do so.
1835 1843
1836The file descriptor being watched. 1844=item ev_io_modify (ev_io *, int events)
1837 1845
1846Similar to C<ev_io_set>, but only changes the requested events. Using this
1847might be faster with some backends, as libev can assume that the C<fd>
1848still refers to the same underlying file description, something it cannot
1849do when using C<ev_io_set>.
1850
1851=item int fd [no-modify]
1852
1853The file descriptor being watched. While it can be read at any time, you
1854must not modify this member even when the watcher is stopped - always use
1855C<ev_io_set> for that.
1856
1838=item int events [read-only] 1857=item int events [no-modify]
1839 1858
1840The events being watched. 1859The set of events the fd is being watched for, among other flags. Remember
1860that this is a bit set - to test for C<EV_READ>, use C<< w->events &
1861EV_READ >>, and similarly for C<EV_WRITE>.
1862
1863As with C<fd>, you must not modify this member even when the watcher is
1864stopped, always use C<ev_io_set> or C<ev_io_modify> for that.
1841 1865
1842=back 1866=back
1843 1867
1844=head3 Examples 1868=head3 Examples
1845 1869
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4243method. 4267method.
4244 4268
4245For C<ev::embed> watchers this method is called C<set_embed>, to avoid 4269For C<ev::embed> watchers this method is called C<set_embed>, to avoid
4246clashing with the C<set (loop)> method. 4270clashing with the C<set (loop)> method.
4247 4271
4272For C<ev::io> watchers there is an additional C<set> method that acepts a
4273new event mask only, and internally calls C<ev_io_modfify>.
4274
4248=item w->start () 4275=item w->start ()
4249 4276
4250Starts the watcher. Note that there is no C<loop> argument, as the 4277Starts the watcher. Note that there is no C<loop> argument, as the
4251constructor already stores the event loop. 4278constructor already stores the event loop.
4252 4279

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