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48 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
48 | EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block |
49 | |
49 | |
50 | =head1 DESCRIPTION |
50 | =head1 DESCRIPTION |
51 | |
51 | |
52 | This module provides an interface to libev |
52 | This module provides an interface to libev |
53 | (L<http://software.schmorp.de/pkg/libev.html>). |
53 | (L<http://software.schmorp.de/pkg/libev.html>). While the documentation |
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54 | below is comprehensive, one might also consult the documentation of libev |
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55 | itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on |
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56 | watcher semantics or some discussion on the available backends, or how to |
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57 | force a specific backend with C<LIBEV_FLAGS>. |
54 | |
58 | |
55 | =cut |
59 | =cut |
56 | |
60 | |
57 | package EV; |
61 | package EV; |
58 | |
62 | |
59 | use strict; |
63 | use strict; |
60 | |
64 | |
61 | BEGIN { |
65 | BEGIN { |
62 | our $VERSION = '1.2'; |
66 | our $VERSION = '1.3'; |
63 | use XSLoader; |
67 | use XSLoader; |
64 | XSLoader::load "EV", $VERSION; |
68 | XSLoader::load "EV", $VERSION; |
65 | } |
69 | } |
66 | |
70 | |
67 | @EV::Io::ISA = |
71 | @EV::IO::ISA = |
68 | @EV::Timer::ISA = |
72 | @EV::Timer::ISA = |
69 | @EV::Periodic::ISA = |
73 | @EV::Periodic::ISA = |
70 | @EV::Signal::ISA = |
74 | @EV::Signal::ISA = |
71 | @EV::Idle::ISA = |
75 | @EV::Idle::ISA = |
72 | @EV::Prepare::ISA = |
76 | @EV::Prepare::ISA = |
… | |
… | |
117 | innermost call to EV::loop return. |
121 | innermost call to EV::loop return. |
118 | |
122 | |
119 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
123 | When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as |
120 | fast as possible. |
124 | fast as possible. |
121 | |
125 | |
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126 | =item EV::once $fh_or_undef, $events, $timeout, $cb->($revents) |
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127 | |
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128 | This function rolls together an I/O and a timer watcher for a single |
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129 | one-shot event without the need for managing a watcher object. |
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130 | |
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131 | If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events> |
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132 | must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ |
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133 | | EV::WRITE>, indicating the type of I/O event you want to wait for. If |
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134 | you do not want to wait for some I/O event, specify C<undef> for |
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135 | C<$fh_or_undef> and C<0> for C<$events>). |
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136 | |
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137 | If timeout is C<undef> or negative, then there will be no |
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138 | timeout. Otherwise a EV::timer with this value will be started. |
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139 | |
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140 | When an error occurs or either the timeout or I/O watcher triggers, then |
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141 | the callback will be called with the received event set (in general |
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142 | you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>, |
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143 | C<EV::WRITE> and C<EV::TIMEOUT>). |
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144 | |
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145 | EV::once doesn't return anything: the watchers stay active till either |
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146 | of them triggers, then they will be stopped and freed, and the callback |
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147 | invoked. |
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148 | |
122 | =back |
149 | =back |
123 | |
150 | |
124 | =head2 WATCHER |
151 | =head2 WATCHER |
125 | |
152 | |
126 | A watcher is an object that gets created to record your interest in some |
153 | A watcher is an object that gets created to record your interest in some |
… | |
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210 | watchers with higher priority will be invoked first. The valid range of |
237 | watchers with higher priority will be invoked first. The valid range of |
211 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
238 | priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default |
212 | -2). If the priority is outside this range it will automatically be |
239 | -2). If the priority is outside this range it will automatically be |
213 | normalised to the nearest valid priority. |
240 | normalised to the nearest valid priority. |
214 | |
241 | |
215 | The default priority of any newly-created weatcher is 0. |
242 | The default priority of any newly-created watcher is 0. |
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243 | |
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244 | Note that the priority semantics have not yet been fleshed out and are |
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245 | subject to almost certain change. |
216 | |
246 | |
217 | =item $w->trigger ($revents) |
247 | =item $w->trigger ($revents) |
218 | |
248 | |
219 | Call the callback *now* with the given event mask. |
249 | Call the callback *now* with the given event mask. |
220 | |
250 | |
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251 | =item $previous_state = $w->keepalive ($bool) |
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252 | |
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253 | Normally, C<EV::loop> will return when there are no active watchers |
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254 | (which is a "deadlock" because no progress can be made anymore). This is |
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255 | convinient because it allows you to start your watchers (and your jobs), |
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256 | call C<EV::loop> once and when it returns you know that all your jobs are |
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257 | finished (or they forgot to register some watchers for their task :). |
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258 | |
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259 | Sometimes, however, this gets in your way, for example when you the module |
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260 | that calls C<EV::loop> (usually the main program) is not the same module |
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261 | as a long-living watcher (for example a DNS client module written by |
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262 | somebody else even). Then you might want any outstanding requests to be |
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263 | handled, but you would not want to keep C<EV::loop> from returning just |
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264 | because you happen to have this long-running UDP port watcher. |
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265 | |
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266 | In this case you can clear the keepalive status, which means that even |
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267 | though your watcher is active, it won't keep C<EV::loop> from returning. |
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268 | |
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269 | The initial value for keepalive is true (enabled), and you cna change it |
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270 | any time. |
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271 | |
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272 | Example: Register an IO watcher for some UDP socket but do not keep the |
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273 | event loop from running just because of that watcher. |
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274 | |
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275 | my $udp_socket = ... |
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276 | my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... }; |
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277 | $udp_watcher->keepalive (0); |
221 | |
278 | |
222 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
279 | =item $w = EV::io $fileno_or_fh, $eventmask, $callback |
223 | |
280 | |
224 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
281 | =item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback |
225 | |
282 | |
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493 | # do nothing unless active |
550 | # do nothing unless active |
494 | $dispatcher->{_event_queue_h} |
551 | $dispatcher->{_event_queue_h} |
495 | or return; |
552 | or return; |
496 | |
553 | |
497 | # make the dispatcher handle any outstanding stuff |
554 | # make the dispatcher handle any outstanding stuff |
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555 | ... not shown |
498 | |
556 | |
499 | # create an IO watcher for each and every socket |
557 | # create an IO watcher for each and every socket |
500 | @snmp_watcher = ( |
558 | @snmp_watcher = ( |
501 | (map { EV::io $_, EV::READ, sub { } } |
559 | (map { EV::io $_, EV::READ, sub { } } |
502 | keys %{ $dispatcher->{_descriptors} }), |
560 | keys %{ $dispatcher->{_descriptors} }), |
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561 | |
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562 | EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE] |
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563 | ? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0), |
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564 | 0, sub { }, |
503 | ); |
565 | ); |
504 | |
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505 | # if there are any timeouts, also create a timer |
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506 | push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { } |
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507 | if $event->[Net::SNMP::Dispatcher::_ACTIVE]; |
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508 | }; |
566 | }; |
509 | |
567 | |
510 | The callbacks are irrelevant, the only purpose of those watchers is |
568 | The callbacks are irrelevant (and are not even being called), the |
511 | to wake up the process as soon as one of those events occurs (socket |
569 | only purpose of those watchers is to wake up the process as soon as |
512 | readable, or timer timed out). The corresponding EV::check watcher will then |
570 | one of those events occurs (socket readable, or timer timed out). The |
513 | clean up: |
571 | corresponding EV::check watcher will then clean up: |
514 | |
572 | |
515 | our $snmp_check = EV::check sub { |
573 | our $snmp_check = EV::check sub { |
516 | # destroy all watchers |
574 | # destroy all watchers |
517 | @snmp_watcher = (); |
575 | @snmp_watcher = (); |
518 | |
576 | |
519 | # make the dispatcher handle any new stuff |
577 | # make the dispatcher handle any new stuff |
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578 | ... not shown |
520 | }; |
579 | }; |
521 | |
580 | |
522 | The callbacks of the created watchers will not be called as the watchers |
581 | The callbacks of the created watchers will not be called as the watchers |
523 | are destroyed before this cna happen (remember EV::check gets called |
582 | are destroyed before this cna happen (remember EV::check gets called |
524 | first). |
583 | first). |
… | |
… | |
527 | |
586 | |
528 | =back |
587 | =back |
529 | |
588 | |
530 | =head1 THREADS |
589 | =head1 THREADS |
531 | |
590 | |
532 | Threads are not supported by this in any way. Perl pseudo-threads is evil |
591 | Threads are not supported by this module in any way. Perl pseudo-threads |
533 | stuff and must die. |
592 | is evil stuff and must die. As soon as Perl gains real threads I will work |
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593 | on thread support for it. |
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594 | |
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595 | =head1 FORK |
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596 | |
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597 | Most of the "improved" event delivering mechanisms of modern operating |
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598 | systems have quite a few problems with fork(2) (to put it bluntly: it is |
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599 | not supported and usually destructive). Libev makes it possible to work |
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600 | around this by having a function that recreates the kernel state after |
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601 | fork in the child. |
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602 | |
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603 | On non-win32 platforms, this module requires the pthread_atfork |
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604 | functionality to do this automatically for you. This function is quite |
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605 | buggy on most BSDs, though, so YMMV. The overhead for this is quite |
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606 | negligible, because everything the function currently does is set a flag |
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607 | that is checked only when the event loop gets used the next time, so when |
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608 | you do fork but not use EV, the overhead is minimal. |
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609 | |
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610 | On win32, there is no notion of fork so all this doesn't apply, of course. |
534 | |
611 | |
535 | =cut |
612 | =cut |
536 | |
613 | |
537 | our $DIED = sub { |
614 | our $DIED = sub { |
538 | warn "EV: error in callback (ignoring): $@"; |
615 | warn "EV: error in callback (ignoring): $@"; |