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Revision 1.57 by root, Thu Apr 24 03:19:28 2008 UTC vs.
Revision 1.60 by root, Fri Apr 25 01:05:26 2008 UTC

… …
207 207
208There are two ways to handle timers: based on real time (relative, "fire 208There are two ways to handle timers: based on real time (relative, "fire
209in 10 seconds") and based on wallclock time (absolute, "fire at 12 209in 10 seconds") and based on wallclock time (absolute, "fire at 12
210o'clock"). 210o'clock").
211 211
212While most event loops expect timers to specified in a relative way, they use 212While most event loops expect timers to specified in a relative way, they
213absolute time internally. This makes a difference when your clock "jumps", 213use absolute time internally. This makes a difference when your clock
214for example, when ntp decides to set your clock backwards from the wrong 2014-01-01 to 214"jumps", for example, when ntp decides to set your clock backwards from
2152008-01-01, a watcher that you created to fire "after" a second might actually take 215the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
216six years to finally fire. 216fire "after" a second might actually take six years to finally fire.
217 217
218AnyEvent cannot compensate for this. The only event loop that is conscious 218AnyEvent cannot compensate for this. The only event loop that is conscious
219about these issues is L<EV>, which offers both relative (ev_timer) and 219about these issues is L<EV>, which offers both relative (ev_timer, based
220absolute (ev_periodic) timers. 220on true relative time) and absolute (ev_periodic, based on wallclock time)
221timers.
221 222
222AnyEvent always prefers relative timers, if available, matching the 223AnyEvent always prefers relative timers, if available, matching the
223AnyEvent API. 224AnyEvent API.
224 225
225=head2 SIGNAL WATCHERS 226=head2 SIGNAL WATCHERS
226 227
227You can watch for signals using a signal watcher, C<signal> is the signal 228You can watch for signals using a signal watcher, C<signal> is the signal
228I<name> without any C<SIG> prefix, C<cb> is the Perl callback to 229I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
229be invoked whenever a signal occurs. 230be invoked whenever a signal occurs.
230 231
231Multiple signals occurances can be clumped together into one callback 232Multiple signal occurances can be clumped together into one callback
232invocation, and callback invocation will be synchronous. synchronous means 233invocation, and callback invocation will be synchronous. synchronous means
233that it might take a while until the signal gets handled by the process, 234that it might take a while until the signal gets handled by the process,
234but it is guarenteed not to interrupt any other callbacks. 235but it is guarenteed not to interrupt any other callbacks.
235 236
236The main advantage of using these watchers is that you can share a signal 237The main advantage of using these watchers is that you can share a signal
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421no warnings; 422no warnings;
422use strict; 423use strict;
423 424
424use Carp; 425use Carp;
425 426
426our $VERSION = '3.12'; 427our $VERSION = '3.2';
427our $MODEL; 428our $MODEL;
428 429
429our $AUTOLOAD; 430our $AUTOLOAD;
430our @ISA; 431our @ISA;
431 432
… …
456 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 457 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
457 my $model = "AnyEvent::Impl::$1"; 458 my $model = "AnyEvent::Impl::$1";
458 if (eval "require $model") { 459 if (eval "require $model") {
459 $MODEL = $model; 460 $MODEL = $model;
460 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 461 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1;
462 } else {
463 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose;
461 } 464 }
462 } 465 }
463 466
464 # check for already loaded models 467 # check for already loaded models
465 unless ($MODEL) { 468 unless ($MODEL) {
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658 661
659=over 4 662=over 4
660 663
661=item C<PERL_ANYEVENT_VERBOSE> 664=item C<PERL_ANYEVENT_VERBOSE>
662 665
666By default, AnyEvent will be completely silent except in fatal
667conditions. You can set this environment variable to make AnyEvent more
668talkative.
669
670When set to C<1> or higher, causes AnyEvent to warn about unexpected
671conditions, such as not being able to load the event model specified by
672C<PERL_ANYEVENT_MODEL>.
673
663When set to C<2> or higher, cause AnyEvent to report to STDERR which event 674When set to C<2> or higher, cause AnyEvent to report to STDERR which event
664model it chooses. 675model it chooses.
665 676
666=item C<PERL_ANYEVENT_MODEL> 677=item C<PERL_ANYEVENT_MODEL>
667 678

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