# WorkerThread

Artifact: [androidx.annotation:annotation](https://developer.android.com/jetpack/androidx/releases/annotation) [View Source](https://cs.android.com/search?q=file:androidx/annotation/WorkerThread.kt+class:androidx.annotation.WorkerThread) Added in [1.0.0](https://developer.android.com/jetpack/androidx/releases/annotation#1.0.0)

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```
@MustBeDocumented
@Retention(value = AnnotationRetention.BINARY)
@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.CONSTRUCTOR, AnnotationTarget.ANNOTATION_CLASS, AnnotationTarget.CLASS, AnnotationTarget.VALUE_PARAMETER])
public annotation WorkerThread
```

<br />

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Denotes that the annotated method should only be called on a worker thread. If the annotated element is a class, then all methods in the class should be called on a worker thread.

Example:

```
@WorkerThread
protected abstract FilterResults performFiltering(CharSequence constraint);
```