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Revision 1.370 by root, Thu Jun 2 23:42:40 2011 UTC vs.
Revision 1.374 by sf-exg, Sat Jun 4 16:54:59 2011 UTC

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178you actually want to know. Also interesting is the combination of 178you actually want to know. Also interesting is the combination of
179C<ev_update_now> and C<ev_now>. 179C<ev_update_now> and C<ev_now>.
180 180
181=item ev_sleep (ev_tstamp interval) 181=item ev_sleep (ev_tstamp interval)
182 182
183Sleep for the given interval: The current thread will be blocked until 183Sleep for the given interval: The current thread will be blocked
184either it is interrupted or the given time interval has passed. Basically 184until either it is interrupted or the given time interval has
185passed (approximately - it might return a bit earlier even if not
186interrupted). Returns immediately if C<< interval <= 0 >>.
187
185this is a sub-second-resolution C<sleep ()>. 188Basically this is a sub-second-resolution C<sleep ()>.
189
190The range of the C<interval> is limited - libev only guarantees to work
191with sleep times of up to one day (C<< interval <= 86400 >>).
186 192
187=item int ev_version_major () 193=item int ev_version_major ()
188 194
189=item int ev_version_minor () 195=item int ev_version_minor ()
190 196
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435example) that can't properly initialise their signal masks. 441example) that can't properly initialise their signal masks.
436 442
437=item C<EVFLAG_NOSIGMASK> 443=item C<EVFLAG_NOSIGMASK>
438 444
439When this flag is specified, then libev will avoid to modify the signal 445When this flag is specified, then libev will avoid to modify the signal
440mask. Specifically, this means you ahve to make sure signals are unblocked 446mask. Specifically, this means you have to make sure signals are unblocked
441when you want to receive them. 447when you want to receive them.
442 448
443This behaviour is useful when you want to do your own signal handling, or 449This behaviour is useful when you want to do your own signal handling, or
444want to handle signals only in specific threads and want to avoid libev 450want to handle signals only in specific threads and want to avoid libev
445unblocking the signals. 451unblocking the signals.
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506totally I<different> file descriptors (even already closed ones, so 512totally I<different> file descriptors (even already closed ones, so
507one cannot even remove them from the set) than registered in the set 513one cannot even remove them from the set) than registered in the set
508(especially on SMP systems). Libev tries to counter these spurious 514(especially on SMP systems). Libev tries to counter these spurious
509notifications by employing an additional generation counter and comparing 515notifications by employing an additional generation counter and comparing
510that against the events to filter out spurious ones, recreating the set 516that against the events to filter out spurious ones, recreating the set
511when required. Epoll also errornously rounds down timeouts, but gives you 517when required. Epoll also erroneously rounds down timeouts, but gives you
512no way to know when and by how much, so sometimes you have to busy-wait 518no way to know when and by how much, so sometimes you have to busy-wait
513because epoll returns immediately despite a nonzero timeout. And last 519because epoll returns immediately despite a nonzero timeout. And last
514not least, it also refuses to work with some file descriptors which work 520not least, it also refuses to work with some file descriptors which work
515perfectly fine with C<select> (files, many character devices...). 521perfectly fine with C<select> (files, many character devices...).
516 522
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946overhead for the actual polling but can deliver many events at once. 952overhead for the actual polling but can deliver many events at once.
947 953
948By setting a higher I<io collect interval> you allow libev to spend more 954By setting a higher I<io collect interval> you allow libev to spend more
949time collecting I/O events, so you can handle more events per iteration, 955time collecting I/O events, so you can handle more events per iteration,
950at the cost of increasing latency. Timeouts (both C<ev_periodic> and 956at the cost of increasing latency. Timeouts (both C<ev_periodic> and
951C<ev_timer>) will be not affected. Setting this to a non-null value will 957C<ev_timer>) will not be affected. Setting this to a non-null value will
952introduce an additional C<ev_sleep ()> call into most loop iterations. The 958introduce an additional C<ev_sleep ()> call into most loop iterations. The
953sleep time ensures that libev will not poll for I/O events more often then 959sleep time ensures that libev will not poll for I/O events more often then
954once per this interval, on average. 960once per this interval, on average (as long as the host time resolution is
961good enough).
955 962
956Likewise, by setting a higher I<timeout collect interval> you allow libev 963Likewise, by setting a higher I<timeout collect interval> you allow libev
957to spend more time collecting timeouts, at the expense of increased 964to spend more time collecting timeouts, at the expense of increased
958latency/jitter/inexactness (the watcher callback will be called 965latency/jitter/inexactness (the watcher callback will be called
959later). C<ev_io> watchers will not be affected. Setting this to a non-null 966later). C<ev_io> watchers will not be affected. Setting this to a non-null
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1379 1386
1380=over 4 1387=over 4
1381 1388
1382=item initialiased 1389=item initialiased
1383 1390
1384Before a watcher can be registered with the event looop it has to be 1391Before a watcher can be registered with the event loop it has to be
1385initialised. This can be done with a call to C<ev_TYPE_init>, or calls to 1392initialised. This can be done with a call to C<ev_TYPE_init>, or calls to
1386C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function. 1393C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function.
1387 1394
1388In this state it is simply some block of memory that is suitable for 1395In this state it is simply some block of memory that is suitable for
1389use in an event loop. It can be moved around, freed, reused etc. at 1396use in an event loop. It can be moved around, freed, reused etc. at
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4897requires, and its I/O model is fundamentally incompatible with the POSIX 4904requires, and its I/O model is fundamentally incompatible with the POSIX
4898model. Libev still offers limited functionality on this platform in 4905model. Libev still offers limited functionality on this platform in
4899the form of the C<EVBACKEND_SELECT> backend, and only supports socket 4906the form of the C<EVBACKEND_SELECT> backend, and only supports socket
4900descriptors. This only applies when using Win32 natively, not when using 4907descriptors. This only applies when using Win32 natively, not when using
4901e.g. cygwin. Actually, it only applies to the microsofts own compilers, 4908e.g. cygwin. Actually, it only applies to the microsofts own compilers,
4902as every compielr comes with a slightly differently broken/incompatible 4909as every compiler comes with a slightly differently broken/incompatible
4903environment. 4910environment.
4904 4911
4905Lifting these limitations would basically require the full 4912Lifting these limitations would basically require the full
4906re-implementation of the I/O system. If you are into this kind of thing, 4913re-implementation of the I/O system. If you are into this kind of thing,
4907then note that glib does exactly that for you in a very portable way (note 4914then note that glib does exactly that for you in a very portable way (note

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