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->stop;
                },
          ) );

          $loop->run;

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>