IO::Async::Loop::Poll(3pm) - Man pages

IO::Async::Loop::Poll(User Contributed Perl DocumentIO::Async::Loop::Poll(3pm)

NAME
       "IO::Async::Loop::Poll" - use "IO::Async" with "poll(2)"

SYNOPSIS
       Normally an instance of this class would not be directly constructed by
       a program. It may however, be useful for runinng IO::Async with an
       existing program already using an "IO::Poll" object.

          use IO::Poll;
          use IO::Async::Loop::Poll;

          my $poll = IO::Poll->new;
          my $loop = IO::Async::Loop::Poll->new( poll => $poll );

          $loop->add( ... );

          while(1) {
             my $timeout = ...
             my $ret = $poll->poll( $timeout );
             $loop->post_poll;
          }

DESCRIPTION
       This subclass of IO::Async::Loop uses the poll(2) system call to
       perform read-ready and write-ready tests.

       By default, this loop will use the underlying "poll()" system call
       directly, bypassing the usual IO::Poll object wrapper around it because
       of a number of bugs and design flaws in that class; namely

       • <https://rt.cpan.org/Ticket/Display.html?id=93107> - IO::Poll relies
         on stable stringification of IO handles

       • <https://rt.cpan.org/Ticket/Display.html?id=25049> - IO::Poll->poll()
         with no handles always returns immediately

       However, to integrate with existing code that uses an "IO::Poll"
       object, a "post_poll" can be called immediately after the "poll" method
       that "IO::Poll" object. The appropriate mask bits are maintained on the
       "IO::Poll" object when notifiers are added or removed from the loop, or
       when they change their "want_*" status. The "post_poll" method inspects
       the result bits and invokes the "on_read_ready" or "on_write_ready"
       methods on the notifiers.

CONSTRUCTOR
   new
          $loop = IO::Async::Loop::Poll->new( %args )

       This function returns a new instance of a "IO::Async::Loop::Poll"
       object. It takes the following named arguments:

       "poll"  The "IO::Poll" object to use for notification. Optional; if a
               value is not given, the underlying "IO::Poll::_poll()" function
               is invoked directly, outside of the object wrapping.

METHODS
   post_poll
          $count = $loop->post_poll

       This method checks the returned event list from a "IO::Poll::poll"
       call, and calls any of the notification methods or callbacks that are
       appropriate.  It returns the total number of callbacks that were
       invoked; that is, the total number of "on_read_ready" and
       "on_write_ready" callbacks for "watch_io", and "watch_time" event
       callbacks.

   loop_once
          $count = $loop->loop_once( $timeout )

       This method calls the "poll" method on the stored "IO::Poll" object,
       passing in the value of $timeout, and then runs the "post_poll" method
       on itself. It returns the total number of callbacks invoked by the
       "post_poll" method, or "undef" if the underlying "poll" method returned
       an error.

AUTHOR
       Paul Evans <leonerd@leonerd.org.uk>

perl v5.34.0                      2022-08-19        IO::Async::Loop::Poll(3pm)

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