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 v5.38.2                                       2024-02-04                         IO::Async::Loop::Poll(3pm)