NAME

       Sys::Virt::Event - Event loop access

DESCRIPTION

       The "Sys::Virt::Event" module represents the contract for integrating libvirt with an
       event loop. This package is abstract and intended to be subclassed to provide an actual
       implementation.

DEPRECATED FUNCTIONALITY

       Event loop implementations used to be required to be instances of sub-classes of
       "Sys::Virt::Event". Instead, they are now required to inherit from "Sys::Virt::EventImpl".
       For backward compatibility with versions 9.4 and older, inheriting from "Sys::Virt::Event"
       is still supported, but will be removed mid 2025.

METHODS

       register_default()
           Register the default libvirt event loop implementation

       run_default()
           Run a single iteration of the default event loop implementation

       register($impl)
           Register an event loop implementation. The implementation should be a instance of a
           sub-class of the "Sys::Virt::EventImpl" package. See the section "EVENT LOOP
           IMPLEMENTATION" below for more information.

       my $watch = Sys::Virt::Event::add_handle($fd, $events, $coderef)
           Adds a watch on the file descriptor $fd for the events $events which is a mask of the
           FILE HANDLE EVENTS constants listed later.  The $coderef parameter is a subroutine to
           invoke when an event is triggered. The subroutine will be passed three parameters, the
           watch identifier, the file descriptor and the event mask. This method returns the
           watch identifier which can be used to update or remove the watch

       Sys::Virt::Event::update_handle($watch, $events)
           Update the event mask for the file descriptor watch $watch to use the events $events.

       Sys::Virt::Event::remove_handle($watch)
           Remove the event mask for the file descriptor watch $watch.

       my $timer = Sys::Virt::Event::add_timeout($frequency, $coderef, $opaque)
           Adds a timeout to trigger with $frequency milliseconds interval.  The $coderef
           parameter is a subroutine to invoke when an event is triggered. The subroutine will be
           passed one parameter, the timer identifier. This method returns the timer identifier
           which can be used to update or remove the timer

       Sys::Virt::Event::update_timeout($timer, $frequency)
           Update the timeout $timer to have the frequency $frequency milliseconds. The values 0
           and -1 have special meaning. The value 0 wants the callback to be invoked on each
           event loop iteration, where -1 stops the callback from being invoked.

       Sys::Virt::Event::remove_timeout($timer)
           Remove the timeout $timer

CONSTANTS

   FILE HANDLE EVENTS
       When integrating with an event loop the following constants define the file descriptor
       events

       Sys::Virt::Event::HANDLE_READABLE
           The file descriptor has data available for read without blocking

       Sys::Virt::Event::HANDLE_WRITABLE
           The file descriptor has ability to write data without blocking

       Sys::Virt::Event::HANDLE_ERROR
           An error occurred on the file descriptor

       Sys::Virt::Event::HANDLE_HANGUP
           The remote end of the file descriptor closed

AUTHORS

       Daniel P. Berrange <berrange@redhat.com>

COPYRIGHT

       Copyright (C) 2006-2009 Red Hat Copyright (C) 2006-2009 Daniel P. Berrange

LICENSE

       This program is free software; you can redistribute it and/or modify it under the terms of
       either the GNU General Public License as published by the Free Software Foundation (either
       version 2 of the License, or at your option any later version), or, the Artistic License,
       as specified in the Perl README file.

SEE ALSO

       Sys::Virt,  "http://libvirt.org"