NAME

    IO::Async::Loop::Epoll - use IO::Async with epoll on Linux

SYNOPSIS

     use IO::Async::Loop::Epoll;
    
     use IO::Async::Stream;
     use IO::Async::Signal;
    
     my $loop = IO::Async::Loop::Epoll->new();
    
     $loop->add( IO::Async::Stream->new(
           read_handle => \*STDIN,
           on_read => sub {
              my ( $self, $buffref ) = @_;
              while( $$buffref =~ s/^(.*)\r?\n// ) {
                 print "You said: $1\n";
              }
           },
     ) );
    
     $loop->add( IO::Async::Signal->new(
           name => 'INT',
           on_receipt => sub {
              print "SIGINT, will now quit\n";
              $loop->loop_stop;
           },
     ) );
    
     $loop->loop_forever();

DESCRIPTION

    This subclass of IO::Async::Loop uses epoll(7) on Linux to perform
    read-ready and write-ready tests so that the O(1) high-performance
    multiplexing of Linux's epoll_pwait(2) syscall can be used.

    The epoll Linux subsystem uses a persistent registration system,
    meaning that better performance can be achieved in programs using a
    large number of filehandles. Each epoll_pwait(2) syscall only has an
    overhead proportional to the number of ready filehandles, rather than
    the total number being watched. For more detail, see the epoll(7)
    manpage.

    This class uses the epoll_pwait(2) system call, which atomically
    switches the process's signal mask, performs a wait exactly as
    epoll_wait(2) would, then switches it back. This allows a process to
    block the signals it cares about, but switch in an empty signal mask
    during the poll, allowing it to handle file IO and signals
    concurrently.

CONSTRUCTOR

 new

       $loop = IO::Async::Loop::Epoll->new()

    This function returns a new instance of a IO::Async::Loop::Epoll
    object.

METHODS

    As this is a subclass of IO::Async::Loop, all of its methods are
    inherited. Expect where noted below, all of the class's methods behave
    identically to IO::Async::Loop.

 loop_once

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

    This method calls epoll_pwait(2), and processes the results of that
    call. It returns the total number of IO::Async::Notifier callbacks
    invoked, or undef if the underlying epoll_pwait() method returned an
    error. If the epoll_pwait() was interrupted by a signal, then 0 is
    returned instead.

SEE ALSO

      * Linux::Epoll - O(1) multiplexing for Linux

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

AUTHOR

    Paul Evans <leonerd@leonerd.org.uk>

