1IO::Async::Timer::PerioUdsiecr(3C)ontributed Perl DocumeInOt:a:tAisoynnc::Timer::Periodic(3)
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6 "IO::Async::Timer::Periodic" - event callback at regular intervals
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9 use IO::Async::Timer::Periodic;
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11 use IO::Async::Loop;
12 my $loop = IO::Async::Loop->new;
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14 my $timer = IO::Async::Timer::Periodic->new(
15 interval => 60,
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17 on_tick => sub {
18 print "You've had a minute\n";
19 },
20 );
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22 $timer->start;
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24 $loop->add( $timer );
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26 $loop->run;
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29 This subclass of IO::Async::Timer implements repeating events at
30 regular clock intervals. The timing may or may not be subject to how
31 long it takes the callback to execute. Iterations may be rescheduled
32 runs at fixed regular intervals beginning at the time the timer was
33 started, or by a fixed delay after the previous code has finished
34 executing.
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36 For a "Timer" object that only runs a callback once, after a given
37 delay, see instead IO::Async::Timer::Countdown. A Countdown timer can
38 also be used to create repeating events that fire at a fixed delay
39 after the previous event has finished processing. See als the examples
40 in "IO::Async::Timer::Countdown".
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43 The following events are invoked, either using subclass methods or CODE
44 references in parameters:
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46 on_tick
47 Invoked on each interval of the timer.
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50 The following named parameters may be passed to "new" or "configure":
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52 on_tick => CODE
53 CODE reference for the "on_tick" event.
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55 interval => NUM
56 The interval in seconds between invocations of the callback or method.
57 Cannot be changed if the timer is running.
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59 first_interval => NUM
60 Optional. If defined, the interval in seconds after calling the "start"
61 method before the first invocation of the callback or method.
62 Thereafter, the regular "interval" will be used. If not supplied, the
63 first interval will be the same as the others.
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65 Even if this value is zero, the first invocation will be made
66 asynchronously, by the containing "Loop" object, and not synchronously
67 by the "start" method itself.
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69 reschedule => STRING
70 Optional. Must be one of "hard", "skip" or "drift". Defines the
71 algorithm used to reschedule the next invocation.
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73 "hard" schedules each iteration at the fixed interval from the previous
74 iteration's schedule time, ensuring a regular repeating event.
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76 "skip" schedules similarly to "hard", but skips over times that have
77 already passed. This matters if the duration is particularly short and
78 there's a possibility that times may be missed, or if the entire
79 process is stopped and resumed by "SIGSTOP" or similar.
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81 "drift" schedules each iteration at the fixed interval from the time
82 that the previous iteration's event handler returns. This allows it to
83 slowly drift over time and become desynchronised with other events of
84 the same interval or multiples/fractions of it.
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86 Once constructed, the timer object will need to be added to the "Loop"
87 before it will work. It will also need to be started by the "start"
88 method.
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91 Paul Evans <leonerd@leonerd.org.uk>
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95perl v5.28.1 2019-02-02 IO::Async::Timer::Periodic(3)