---
name: "IO::Poll"
section: "3perl"
platform: "linux"
package: "perl"
version: "5.44.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/IO::Poll/3perl"
---

# IO::Poll(3perl)

Object interface to system poll call

## NAME

IO::Poll - Object interface to system poll call

## SYNOPSIS

```
    use IO::Poll qw(POLLRDNORM POLLWRNORM POLLIN POLLHUP);
    $poll = IO::Poll->new();
    $poll->mask($input_handle => POLLIN);
    $poll->mask($output_handle => POLLOUT);
    $poll->poll($timeout);
    $ev = $poll->events($input);
```

## DESCRIPTION

`"IO::Poll"` is a simple interface to the system level poll routine.

## METHODS

- mask ( IO \[, EVENT\_MASK \] )

  If EVENT\_MASK is given, then, if EVENT\_MASK is non-zero, IO is added to the list of file descriptors and the next call to poll will check for any event specified in EVENT\_MASK. If EVENT\_MASK is zero then IO will be removed from the list of file descriptors.

  If EVENT\_MASK is not given then the return value will be the current event mask value for IO.

- poll ( \[ TIMEOUT \] )

  Call the system level poll routine. If TIMEOUT is not specified then the call will block. Returns the number of handles which had events happen, or -1 on error.

- events ( IO )

  Returns the event mask which represents the events that happened on IO during the last call to `"poll"`.

- remove ( IO )

  Remove IO from the list of file descriptors for the next poll.

- handles( \[ EVENT\_MASK \] )

  Returns a list of handles. If EVENT\_MASK is not given then a list of all handles known will be returned. If EVENT\_MASK is given then a list of handles will be returned which had one of the events specified by EVENT\_MASK happen during the last call to `"poll"`.

## SEE ALSO

[**poll**(2)](/poll/2.md), IO::Handle, IO::Select

## AUTHOR

Graham Barr. Currently maintained by the Perl Porters.  Please report all bugs at \<https://github.com/Perl/perl5/issues\>.

## COPYRIGHT

Copyright (c) 1997-8 Graham Barr \<gbarr@pobox.com\>. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.