# Plugin Helper: Thread

The `thread` plugin helper manages threads and these threads are integrated with plugins. No need manual run or shutdown in the plugin.

Here is an example:

```ruby
require 'fluent/plugin/output'

module Fluent::Plugin
  class ExampleOutput < Output
    Fluent::Plugin.register_output('example', self)

    # 1. Load thread helper
    helpers :thread

    # Omit `configure`, `shutdown` and other plugin APIs

    def start
      super

      # 2. Create and run thread with unique name.
      thread_create(:example_thread_run, &method(:run))
    end

    def run
      # ...
    end
  end
end
```

The launched thread is managed by the plugin helper. No need of thread shutdown code in plugin's `shutdown` method. It shutdowns the launched threads automatically.

## Methods

### `thread_create(title)`

This method creates a thread and runs it with the given routine.

`title` must be unique.

```ruby
# Pass block directly
thread_create(:example_plugin_main) {
  # ...
}

# Pass method object with existing method
thread_create(:foo_plugin_body, &method(:run))
def run
  # ...
end
```

### `thread_current_running?`

Checks whether the current thread is running or not. This method is available in the running block.

```ruby
thread_create(:example_plugin_main) {
  while thread_current_running?
    # ...
  end
}
```

## Plugins using `thread`

* [`out_forward`](https://docs.fluentd.org/output/forward)
* [`in_monitor_agent`](https://docs.fluentd.org/input/monitor_agent)
* [`in_sample`](https://docs.fluentd.org/input/sample)

If this article is incorrect or outdated, or omits critical information, please [let us know](https://github.com/fluent/fluentd-docs-gitbook/issues?state=open). [Fluentd](http://www.fluentd.org/) is an open-source project under [Cloud Native Computing Foundation (CNCF)](https://cncf.io/). All components are available under the Apache 2 License.