---
name: "IO::Async::Timer"
section: "3pm"
platform: "linux"
package: "libio-async-perl"
version: "0.804-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/IO::Async::Timer"
---

# IO::Async::Timer(3pm)

base class for Notifiers that use timed delays

## NAME

"IO::Async::Timer" - base class for Notifiers that use timed delays

## DESCRIPTION

This module provides a subclass of IO::Async::Notifier for implementing notifiers that use timed delays. For specific implementations, see one of the subclasses:

- •

  IO::Async::Timer::Absolute - event callback at a fixed future time

- •

  IO::Async::Timer::Countdown - event callback after a fixed delay

- •

  IO::Async::Timer::Periodic - event callback at regular intervals

## CONSTRUCTOR

### new

```
   $timer = IO::Async::Timer->new( %args );
```

Constructs a particular subclass of `"IO::Async::Timer"` object, and returns it. This constructor is provided for backward compatibility to older code which doesn't use the subclasses. New code should directly construct a subclass instead.

- mode =\> STRING

  The type of timer to create. Currently the only allowed mode is `"countdown"` but more types may be added in the future.

Once constructed, the `"Timer"` will need to be added to the `"Loop"` before it will work. It will also need to be started by the `"start"` method.

## METHODS

### is\_running

```
   $running = $timer->is_running;
```

Returns true if the Timer has been started, and has not yet expired, or been stopped.

### start

```
   $timer->start;
```

Starts the Timer. Throws an error if it was already running.

If the Timer is not yet in a Loop, the actual start will be deferred until it is added. Once added, it will be running, and will expire at the given duration after the time it was added.

As a convenience, `$timer` is returned. This may be useful for starting timers at construction time:

```
   $loop->add( IO::Async::Timer->new( ... )->start );
```

### stop

```
   $timer->stop;
```

Stops the Timer if it is running. If it has not yet been added to the `"Loop"` but there is a start pending, this will cancel it.

## AUTHOR

Paul Evans \<leonerd@leonerd.org.uk\>