| … | |
… | |
| 114 | =item ev_tstamp ev_time () |
114 | =item ev_tstamp ev_time () |
| 115 | |
115 | |
| 116 | Returns the current time as libev would use it. Please note that the |
116 | Returns the current time as libev would use it. Please note that the |
| 117 | C<ev_now> function is usually faster and also often returns the timestamp |
117 | C<ev_now> function is usually faster and also often returns the timestamp |
| 118 | you actually want to know. |
118 | you actually want to know. |
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119 | |
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120 | =item ev_sleep (ev_tstamp interval) |
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121 | |
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122 | Sleep for the given interval: The current thread will be blocked until |
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123 | either it is interrupted or the given time interval has passed. Basically |
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124 | this is a subsecond-resolution C<sleep ()>. |
| 119 | |
125 | |
| 120 | =item int ev_version_major () |
126 | =item int ev_version_major () |
| 121 | |
127 | |
| 122 | =item int ev_version_minor () |
128 | =item int ev_version_minor () |
| 123 | |
129 | |
| … | |
… | |
| 569 | Example: For some weird reason, unregister the above signal handler again. |
575 | Example: For some weird reason, unregister the above signal handler again. |
| 570 | |
576 | |
| 571 | ev_ref (loop); |
577 | ev_ref (loop); |
| 572 | ev_signal_stop (loop, &exitsig); |
578 | ev_signal_stop (loop, &exitsig); |
| 573 | |
579 | |
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|
580 | =item ev_set_io_collect_interval (loop, ev_tstamp interval) |
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581 | |
|
|
582 | =item ev_set_timeout_collect_interval (loop, ev_tstamp interval) |
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|
583 | |
|
|
584 | These advanced functions influence the time that libev will spend waiting |
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585 | for events. Both are by default C<0>, meaning that libev will try to |
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586 | invoke timer/periodic callbacks and I/O callbacks with minimum latency. |
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587 | |
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588 | Setting these to a higher value (the C<interval> I<must> be >= C<0>) |
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589 | allows libev to delay invocation of I/O and timer/periodic callbacks to |
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590 | increase efficiency of loop iterations. |
|
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591 | |
|
|
592 | The background is that sometimes your program runs just fast enough to |
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593 | handle one (or very few) event(s) per loop iteration. While this makes |
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594 | the program responsive, it also wastes a lot of CPU time to poll for new |
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595 | events, especially with backends like C<select ()> which have a high |
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596 | overhead for the actual polling but can deliver many events at once. |
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597 | |
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598 | By setting a higher I<io collect interval> you allow libev to spend more |
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599 | time collecting I/O events, so you can handle more events per iteration, |
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600 | at the cost of increasing latency. Timeouts (both C<ev_periodic> and |
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601 | C<ev_timer>) will be not affected. |
|
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602 | |
|
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603 | Likewise, by setting a higher I<timeout collect interval> you allow libev |
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604 | to spend more time collecting timeouts, at the expense of increased |
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605 | latency (the watcher callback will be called later). C<ev_io> watchers |
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606 | will not be affected. |
|
|
607 | |
|
|
608 | Many programs can usually benefit by setting the io collect interval to |
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609 | a value near C<0.1> or so, which is often enough for interactive servers |
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610 | (of course not for games), likewise for timeouts. It usually doesn't make |
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611 | much sense to set it to a lower value than C<0.01>, as this approsaches |
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612 | the timing granularity of most systems. |
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613 | |
| 574 | =back |
614 | =back |
| 575 | |
615 | |
| 576 | |
616 | |
| 577 | =head1 ANATOMY OF A WATCHER |
617 | =head1 ANATOMY OF A WATCHER |
| 578 | |
618 | |
| … | |
… | |
| 2297 | runtime if successful). Otherwise no use of the realtime clock option will |
2337 | runtime if successful). Otherwise no use of the realtime clock option will |
| 2298 | be attempted. This effectively replaces C<gettimeofday> by C<clock_get |
2338 | be attempted. This effectively replaces C<gettimeofday> by C<clock_get |
| 2299 | (CLOCK_REALTIME, ...)> and will not normally affect correctness. See the |
2339 | (CLOCK_REALTIME, ...)> and will not normally affect correctness. See the |
| 2300 | note about libraries in the description of C<EV_USE_MONOTONIC>, though. |
2340 | note about libraries in the description of C<EV_USE_MONOTONIC>, though. |
| 2301 | |
2341 | |
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2342 | =item EV_USE_NANOSLEEP |
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2343 | |
|
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2344 | If defined to be C<1>, libev will assume that C<nanosleep ()> is available |
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2345 | and will use it for delays. Otherwise it will use C<select ()>. |
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2346 | |
| 2302 | =item EV_USE_SELECT |
2347 | =item EV_USE_SELECT |
| 2303 | |
2348 | |
| 2304 | If undefined or defined to be C<1>, libev will compile in support for the |
2349 | If undefined or defined to be C<1>, libev will compile in support for the |
| 2305 | C<select>(2) backend. No attempt at autodetection will be done: if no |
2350 | C<select>(2) backend. No attempt at autodetection will be done: if no |
| 2306 | other method takes over, select will be it. Otherwise the select backend |
2351 | other method takes over, select will be it. Otherwise the select backend |
