Linux::FD::Timer - Timer filehandles for Linux


version 0.011


 use Linux::FD::Timer;

 my $fh = Linux::FD::Timer->new('monotonic');
 $fh->set_timeout(10, 10);
 while (1) {
     #do something..
     $fh->wait; #until the 10 seconds have passed.


This module creates and operates on a timer that delivers timer expiration notifications via a file descriptor. It provides an alternative to the use of Time::HiRes' setitimer or POSIX::RT::Timer, with the advantage that the file descriptor may easily be monitored by mechanisms such as select, poll, and epoll.



This creates a new timer object, and returns a file handle that refers to that timer. The clockid argument specifies the clock that is used to mark the progress of the timer, and must be either 'realtime' or 'monotonic'. realtime is a settable system-wide clock. monotonic is a non-settable clock that is not affected by discontinuous changes in the system clock (e.g., manual changes to system time). The current value of each of these clocks can be retrieved using POSIX::RT::Clock.


Get the timeout value. In list context, it also returns the interval value. Note that this value is always relative to the current time.

set_timeout(value, $interval = 0, $abs_time = 0)

Set the timer and interval values. If $abstime is true, they are absolute values, otherwise they are relative to the current time. Returns the old value like get_time does.


If the timer has already expired one or more times since its settings were last modified using settime(), or since the last successful wait, then receive returns an unsigned 64-bit integer containing the number of expirations that have occurred. If not it either returns undef or it blocks (if the handle is blocking).


Leon Timmermans <>


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.