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| 5 | loops |
5 | loops |
| 6 | |
6 | |
| 7 | SYNOPSIS |
7 | SYNOPSIS |
| 8 | use AnyEvent; |
8 | use AnyEvent; |
| 9 | |
9 | |
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10 | # file descriptor readable |
| 10 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... }); |
11 | my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); |
| 11 | |
12 | |
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13 | # one-shot or repeating timers |
| 12 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
14 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
| 13 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
15 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
| 14 | |
16 | |
| 15 | print AnyEvent->now; # prints current event loop time |
17 | print AnyEvent->now; # prints current event loop time |
| 16 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
18 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
| 17 | |
19 | |
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20 | # POSIX signal |
| 18 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
21 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
| 19 | |
22 | |
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23 | # child process exit |
| 20 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
24 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
| 21 | my ($pid, $status) = @_; |
25 | my ($pid, $status) = @_; |
| 22 | ... |
26 | ... |
| 23 | }); |
27 | }); |
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28 | |
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29 | # called when event loop idle (if applicable) |
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30 | my $w = AnyEvent->idle (cb => sub { ... }); |
| 24 | |
31 | |
| 25 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
32 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
| 26 | $w->send; # wake up current and all future recv's |
33 | $w->send; # wake up current and all future recv's |
| 27 | $w->recv; # enters "main loop" till $condvar gets ->send |
34 | $w->recv; # enters "main loop" till $condvar gets ->send |
| 28 | # use a condvar in callback mode: |
35 | # use a condvar in callback mode: |
| … | |
… | |
| 400 | ); |
407 | ); |
| 401 | |
408 | |
| 402 | # do something else, then wait for process exit |
409 | # do something else, then wait for process exit |
| 403 | $done->recv; |
410 | $done->recv; |
| 404 | |
411 | |
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412 | IDLE WATCHERS |
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413 | Sometimes there is a need to do something, but it is not so important to |
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414 | do it instantly, but only when there is nothing better to do. This |
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415 | "nothing better to do" is usually defined to be "no other events need |
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416 | attention by the event loop". |
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417 | |
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418 | Idle watchers ideally get invoked when the event loop has nothing better |
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419 | to do, just before it would block the process to wait for new events. |
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420 | Instead of blocking, the idle watcher is invoked. |
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421 | |
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422 | Most event loops unfortunately do not really support idle watchers (only |
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423 | EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent |
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424 | will simply call the callback "from time to time". |
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425 | |
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426 | Example: read lines from STDIN, but only process them when the program |
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427 | is otherwise idle: |
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428 | |
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429 | my @lines; # read data |
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430 | my $idle_w; |
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431 | my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
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432 | push @lines, scalar <STDIN>; |
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433 | |
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434 | # start an idle watcher, if not already done |
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435 | $idle_w ||= AnyEvent->idle (cb => sub { |
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436 | # handle only one line, when there are lines left |
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437 | if (my $line = shift @lines) { |
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438 | print "handled when idle: $line"; |
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439 | } else { |
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440 | # otherwise disable the idle watcher again |
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441 | undef $idle_w; |
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442 | } |
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443 | }); |
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444 | }); |
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445 | |
| 405 | CONDITION VARIABLES |
446 | CONDITION VARIABLES |
| 406 | If you are familiar with some event loops you will know that all of them |
447 | If you are familiar with some event loops you will know that all of them |
| 407 | require you to run some blocking "loop", "run" or similar function that |
448 | require you to run some blocking "loop", "run" or similar function that |
| 408 | will actively watch for new events and call your callbacks. |
449 | will actively watch for new events and call your callbacks. |
| 409 | |
450 | |
