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Comparing libev/ev.pod (file contents):
Revision 1.457 by root, Fri Sep 6 22:17:52 2019 UTC vs.
Revision 1.461 by root, Wed Jan 22 12:15:52 2020 UTC

… …
480unblocking the signals. 480unblocking the signals.
481 481
482It's also required by POSIX in a threaded program, as libev calls 482It's also required by POSIX in a threaded program, as libev calls
483C<sigprocmask>, whose behaviour is officially unspecified. 483C<sigprocmask>, whose behaviour is officially unspecified.
484 484
485This flag's behaviour will become the default in future versions of libev. 485=item C<EVFLAG_NOTIMERFD>
486
487When this flag is specified, the libev will avoid using a C<timerfd> to
488detect time jumps. It will still be able to detect time jumps, but takes
489longer and has a lower accuracy in doing so, but saves a file descriptor
490per loop.
491
492The current implementation only tries to use a C<timerfd> when the first
493C<ev_periodic> watcher is started and falls back on other methods if it
494cannot 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
489This is your standard select(2) backend. Not I<completely> standard, as 498This is your standard select(2) backend. Not I<completely> standard, as
490libev tries to roll its own fd_set with no limits on the number of fds, 499libev tries to roll its own fd_set with no limits on the number of fds,
… …
1209with a watcher-specific start function (C<< ev_TYPE_start (loop, watcher 1218with 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
1211corresponding stop function (C<< ev_TYPE_stop (loop, watcher *) >>. 1220corresponding stop function (C<< ev_TYPE_stop (loop, watcher *) >>.
1212 1221
1213As 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
1214must not touch the values stored in it. Most specifically you must never 1223must not touch the values stored in it except when explicitly documented
1215reinitialise 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.
1216 1226
1217Each and every callback receives the event loop pointer as first, the 1227Each and every callback receives the event loop pointer as first, the
1218registered watcher structure as second, and a bitset of received events as 1228registered watcher structure as second, and a bitset of received events as
1219third argument. 1229third argument.
1220 1230
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1639 1649
1640This section describes each watcher in detail, but will not repeat 1650This section describes each watcher in detail, but will not repeat
1641information given in the last section. Any initialisation/set macros, 1651information given in the last section. Any initialisation/set macros,
1642functions and members specific to the watcher type are explained. 1652functions and members specific to the watcher type are explained.
1643 1653
1644Members are additionally marked with either I<[read-only]>, meaning that, 1654Most members are additionally marked with either I<[read-only]>, meaning
1645while 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
1646sensible 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
1647watcher is stopped to your hearts content), or I<[read-write]>, which 1657the watcher is stopped to your hearts content), or I<[read-write]>, which
1648means 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
1649is active, but you can also modify it. Modifying it may not do something 1659is active, but you can also modify it. Modifying it may not do something
1650sensible or take immediate effect (or do anything at all), but libev will 1660sensible or take immediate effect (or do anything at all), but libev will
1651not crash or malfunction in any way. 1661not crash or malfunction in any way.
1652 1662
1663In any case, the documentation for each member will explain what the
1664effects are, and if there are any additional access restrictions.
1653 1665
1654=head2 C<ev_io> - is this file descriptor readable or writable? 1666=head2 C<ev_io> - is this file descriptor readable or writable?
1655 1667
1656I/O watchers check whether a file descriptor is readable or writable 1668I/O watchers check whether a file descriptor is readable or writable
1657in each iteration of the event loop, or, more precisely, when reading 1669in each iteration of the event loop, or, more precisely, when reading
… …
1820 1832
1821Configures an C<ev_io> watcher. The C<fd> is the file descriptor to 1833Configures an C<ev_io> watcher. The C<fd> is the file descriptor to
1822receive events for and C<events> is either C<EV_READ>, C<EV_WRITE> or 1834receive events for and C<events> is either C<EV_READ>, C<EV_WRITE> or
1823C<EV_READ | EV_WRITE>, to express the desire to receive the given events. 1835C<EV_READ | EV_WRITE>, to express the desire to receive the given events.
1824 1836
1825=item int fd [read-only] 1837=item ev_io_modify (ev_io *, int events)
1826 1838
1827The file descriptor being watched. 1839Similar to C<ev_io_set>, but only changes the event mask. Using this might
1840be faster with some backends, as libev can assume that the C<fd> still
1841refers to the same underlying file description, something it cannot do
1842when using C<ev_io_set>.
1828 1843
1844=item int fd [no-modify]
1845
1846The file descriptor being watched. While it can be read at any time, you
1847must not modify this member even when the watcher is stopped - always use
1848C<ev_io_set> for that.
1849
1829=item int events [read-only] 1850=item int events [no-modify]
1830 1851
1831The events being watched. 1852The set of events the fd is being watched for, among other flags. Remember
1853that this is a bit set - to test for C<EV_READ>, use C<< w->events &
1854EV_READ >>, and similarly for C<EV_WRITE>.
1855
1856As with C<fd>, you must not modify this member even when the watcher is
1857stopped, always use C<ev_io_set> or C<ev_io_modify> for that.
1832 1858
1833=back 1859=back
1834 1860
1835=head3 Examples 1861=head3 Examples
1836 1862
… …
4234method. 4260method.
4235 4261
4236For C<ev::embed> watchers this method is called C<set_embed>, to avoid 4262For C<ev::embed> watchers this method is called C<set_embed>, to avoid
4237clashing with the C<set (loop)> method. 4263clashing with the C<set (loop)> method.
4238 4264
4265For C<ev::io> watchers there is an additional C<set> method that acepts a
4266new event mask only, and internally calls C<ev_io_modfify>.
4267
4239=item w->start () 4268=item w->start ()
4240 4269
4241Starts the watcher. Note that there is no C<loop> argument, as the 4270Starts the watcher. Note that there is no C<loop> argument, as the
4242constructor already stores the event loop. 4271constructor already stores the event loop.
4243 4272
… …
4606 4635
4607=item EV_USE_NANOSLEEP 4636=item EV_USE_NANOSLEEP
4608 4637
4609If defined to be C<1>, libev will assume that C<nanosleep ()> is available 4638If defined to be C<1>, libev will assume that C<nanosleep ()> is available
4610and will use it for delays. Otherwise it will use C<select ()>. 4639and will use it for delays. Otherwise it will use C<select ()>.
4640
4641=item EV_USE_EVENTFD
4642
4643If defined to be C<1>, then libev will assume that C<eventfd ()> is
4644available and will probe for kernel support at runtime. This will improve
4645C<ev_signal> and C<ev_async> performance and reduce resource consumption.
4646If undefined, it will be enabled if the headers indicate GNU/Linux + Glibc
46472.7 or newer, otherwise disabled.
4648
4649=item EV_USE_SIGNALFD
4650
4651If defined to be C<1>, then libev will assume that C<signalfd ()> is
4652available and will probe for kernel support at runtime. This enables
4653the use of EVFLAG_SIGNALFD for faster and simpler signal handling. If
4654undefined, it will be enabled if the headers indicate GNU/Linux + Glibc
46552.7 or newer, otherwise disabled.
4656
4657=item EV_USE_TIMERFD
4658
4659If defined to be C<1>, then libev will assume that C<timerfd ()> is
4660available and will probe for kernel support at runtime. This allows
4661libev to detect time jumps accurately. If undefined, it will be enabled
4662if the headers indicate GNU/Linux + Glibc 2.8 or newer and define
4663C<TFD_TIMER_CANCEL_ON_SET>, otherwise disabled.
4611 4664
4612=item EV_USE_EVENTFD 4665=item EV_USE_EVENTFD
4613 4666
4614If defined to be C<1>, then libev will assume that C<eventfd ()> is 4667If defined to be C<1>, then libev will assume that C<eventfd ()> is
4615available and will probe for kernel support at runtime. This will improve 4668available and will probe for kernel support at runtime. This will improve

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