NAME

       "IO::Async::Timer::Periodic" - event callback at regular intervals

SYNOPSIS

        use IO::Async::Timer::Periodic;

        use IO::Async::Loop;
        my $loop = IO::Async::Loop->new;

        my $timer = IO::Async::Timer::Periodic->new(
           interval => 60,

           on_tick => sub {
              print "You've had a minute\n";
           },
        );

        $timer->start;

        $loop->add( $timer );

        $loop->run;

DESCRIPTION

       This subclass of IO::Async::Timer implements repeating events at regular clock intervals. The timing may
       or may not be subject to how long it takes the callback to execute. Iterations may be rescheduled runs at
       fixed regular intervals beginning at the time the timer was started, or by a fixed delay after the
       previous code has finished executing.

       For a "Timer" object that only runs a callback once, after a given delay, see instead
       IO::Async::Timer::Countdown. A Countdown timer can also be used to create repeating events that fire at a
       fixed delay after the previous event has finished processing. See als the examples in
       "IO::Async::Timer::Countdown".

EVENTS

       The following events are invoked, either using subclass methods or CODE references in parameters:

   on_tick
       Invoked on each interval of the timer.

PARAMETERS

       The following named parameters may be passed to "new" or "configure":

       on_tick => CODE
               CODE reference for the "on_tick" event.

       interval => NUM
               The  interval  in seconds between invocations of the callback or method. Cannot be changed if the
               timer is running.

       first_interval => NUM
               Optional. If defined, the interval in seconds after calling the "start" method before  the  first
               invocation  of  the  callback  or method. Thereafter, the regular "interval" will be used. If not
               supplied, the first interval will be the same as the others.

               Even if this value is zero, the first invocation will be made asynchronously, by  the  containing
               "Loop" object, and not synchronously by the "start" method itself.

       reschedule => STRING
               Optional.  Must be one of "hard", "skip" or "drift". Defines the algorithm used to reschedule the
               next invocation.

               "hard" schedules each iteration at the fixed interval  from  the  previous  iteration's  schedule
               time, ensuring a regular repeating event.

               "skip" schedules similarly to "hard", but skips over times that have already passed. This matters
               if  the  duration is particularly short and there's a possibility that times may be missed, or if
               the entire process is stopped and resumed by "SIGSTOP" or similar.

               "drift" schedules each  iteration  at  the  fixed  interval  from  the  time  that  the  previous
               iteration's  event  handler  returns.  This  allows  it  to  slowly  drift  over  time and become
               desynchronised with other events of the same interval or multiples/fractions of it.

       Once constructed, the timer object will need to be added to the "Loop" before it will work. It will  also
       need to be started by the "start" method.

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>

perl v5.18.1                                       2013-10-25                    IO::Async::Timer::Periodic(3pm)