/ 
Linux-Event-0.006
/ Linux::Event::Backend

NAME

Linux::Event::Backend - Backend contract for Linux::Event::Loop

DESCRIPTION

This module documents the minimal backend interface expected by Linux::Event::Loop. Backends are intentionally duck-typed.

The loop owns scheduling policy (clock/timer/scheduler). The backend owns the wait/dispatch mechanism (epoll now, io_uring later).

STATUS

As of version 0.006, the backend contract described here is considered stable. New optional methods may be added in future releases, but required methods and callback ABI will not change.

REQUIRED METHODS

new(%args)

Create the backend instance.

watch($fh, $mask, $cb, %opt) -> $fd

Register a filehandle for readiness notifications.

Callback signature (standardized by this project):

$cb->($loop, $fh, $fd, $mask, $tag);

Where:

  • $loop is the Linux::Event::Loop instance

  • $fh is the watched filehandle

  • $fd is the integer file descriptor

  • $mask is an integer readiness mask (backend-defined bit layout, standardized within this project)

  • $tag is an arbitrary user value (optional; may be undef)

Backends may accept additional options in %opt. This distribution uses:

  • _loop - the loop reference to pass through to the callback

  • tag - the tag value to pass through to the callback

unwatch($fh_or_fd) -> $bool

Remove a watcher by filehandle or file descriptor.

run_once($loop, $timeout_s=undef) -> $n

Block until events occur (or timeout) and dispatch them.

Return value is backend-defined; for now callers should not rely on it.

OPTIONAL METHODS

modify($fh_or_fd, $mask, %opt) -> $bool

Update an existing watcher registration (e.g. add/remove interest in writable). If not implemented, the loop may fall back to unwatch+watch.

SEE ALSO

Linux::Event::Loop, Linux::Event::Backend::Epoll

SYNOPSIS

# Internal. See L<Linux::Event::Loop>.

VERSION

This document describes Linux::Event::Backend version 0.006.

AUTHOR

Joshua S. Day

LICENSE

Same terms as Perl itself.