Provided by: liblinux-epoll-perl_0.016-1_amd64 bug

NAME

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

VERSION

       version 0.016

SYNOPSIS

        use Linux::Epoll;

        my $epoll = Linux::Epoll->new();
        $epoll->add($fh, 'in', sub {
            my $events = shift;
            do_something($fh) if $events->{in};
        });
        $epoll->wait while 1;

DESCRIPTION

       Epoll is a multiplexing mechanism that scales up O(1) with number of watched files.
       Linux::Epoll is a callback style epoll module, unlike other epoll modules available on
       CPAN.

   Types of events
       ·   in

           The associated filehandle is available for reading.

       ·   out

           The associated filehandle is available for writing.

       ·   err

           An error condition has happened on the associated filehandle. "wait" will always wait
           on this event, it is not necessary to set this with "add" or "modify".

       ·   prio

           There is urgent data available for reading.

       ·   et

           Set edge triggered behavior for the associated filehandle. The default behavior is
           level triggered. See you epoll(7) documentation for more information on what this
           means.

           Take note that when using edge triggered events, exceptions out of the wait can easily
           cause events to be lost (when consuming to more than one event at a time).

       ·   hup

           A hang-up has happened on the associated filehandle. "wait" will always wait on this
           event, it is not necessary to set this with "add" or "modify".

       ·   rdhup

           Stream socket peer closed the connection, or shut down the writing half of connection.
           This flag is especially useful for writing simple code to detect peer shutdown when
           using Edge Triggered monitoring.

       ·   oneshot

           Sets the one-shot behavior for the associated file descriptor. This means that after
           an event is pulled out with "wait" the associated file descriptor is internally
           disabled and no other events will be reported by the epoll interface. The user must
           call "modify" to rearm the file descriptor with a new event mask.

       ·   wakeup

           If "oneshot" and "et" are clear and the process has the "CAP_BLOCK_SUSPEND"
           capability, ensure that the system does not enter "suspend" or "hibernate" while this
           event is pending or being processed. The event is considered as being "processed" from
           the time when it is returned by a call to epoll_wait(2) until the next call to
           epoll_wait(2) on the same epoll(7) file descriptor, the closure of that file
           descriptor, the removal of the event file descriptor with EPOLL_CTL_DEL, or the
           clearing of EPOLLWAKEUP for the event file descriptor with EPOLL_CTL_MOD.

       ·   exclusive

           Sets an exclusive wakeup mode for the epoll file descriptor that is being attached to
           the target file descriptor, fd. When a wakeup event occurs and multiple epoll file
           descriptors are attached to the same target file using "exclusive", one or more of the
           epoll file descriptors will receive an event with "wait()". The default in this
           scenario (when "exclusive" is not set) is for all epoll file descriptors to receive an
           event. "exclusive" is thus useful for avoiding thundering herd problems in certain
           scenarios.

           If the same file descriptor is in multiple epoll instances, some with the "exclusive"
           flag, and others without, then events will be provided to all epoll instances that did
           not specify "exclusive", and at least one of the epoll instances that did specify
           "exclusive".

           The following values may be specified in conjunction with "exclusive": "in", "out",
           "wakeup", and "et". "hup" and "err" can also be specified, but this is not required:
           as usual, these events are always reported if they occur, regardless of whether they
           are specified in events. Attempts to specify other values in events yield an error.
           "exclusive" may be used only in an "add()" operation; attempts to employ it with
           "modify" yield an error. If "exclusive" has been set using "add()", then a subsequent
           "modify()" on the same epfd, fd pair yields an error. A call to "add(" that specifies
           "exclusive" in events and specifies the target file descriptor fd as an epoll instance
           will likewise fail. The error in all of these cases is "EINVAL".

METHODS

   new()
       Create a new epoll instance.

   add($fh, $events, $callback)
       Register the filehandle with the epoll instance and associate events $events and callback
       $callback with it. $events may be either a string (e.g. 'in') or an arrayref (e.g. "[qw/in
       out hup/]"). If a filehandle already exists in the set and "add" is called in non-void
       context, it returns undef and sets $! to "EEXIST"; if the file can't be waited upon it
       sets $! to "EPERM" instead. On all other error conditions an exception is thrown. The
       callback gets a single argument, a hashref whose keys are the triggered events.

   modify($fh, $events, $callback)
       Change the events and callback associated on this epoll instance with filehandle $fh. The
       arguments work the same as with "add". If a filehandle doesn't exist in the set and
       "modify" is called in non-void context, it returns undef and sets $! to "ENOENT". On all
       other error conditions an exception is thrown.

   delete($fh)
       Remove a filehandle from the epoll instance. If a filehandle doesn't exist in the set and
       "delete" is called in non-void context, it returns undef and sets $! to "ENOENT". On all
       other error conditions an exception is thrown.

   wait($number = 1, $timeout = undef, $sigmask = undef)
       Wait for up to $number events, where $number must be greater than zero. $timeout is the
       maximal time "wait" will wait for events in fractional seconds. If it is undefined it may
       wait indefinitely. $sigmask is the signal mask during the call. If it is not defined the
       signal mask will be untouched. If interrupted by a signal it returns undef/an empty list
       and sets $! to "EINTR". On all other error conditions an exception is thrown.

REQUIREMENTS

       This module requires at least Perl 5.10 and Linux 2.6.19 to function correctly.

SEE ALSO

       ·   IO::Epoll

       ·   Sys::Syscall

       ·   IO::Poll

AUTHOR

       Leon Timmermans <leont@cpan.org>

COPYRIGHT AND LICENSE

       This software is copyright (c) 2010 by Leon Timmermans.

       This is free software; you can redistribute it and/or modify it under the same terms as
       the Perl 5 programming language system itself.