# GetAllUnmanagedSystems(AllocatorHandle)

> Retrieve an array of all unmanaged systems in this world

## Definition

* **Type:** Method
* **Namespace:** [Unity.Entities](/engine/7000.0/script-reference/unity/entities.md)
* **Assembly:** UnityEngine.EntitiesModule

```csharp
public NativeArray<SystemHandle> GetAllUnmanagedSystems(AllocatorManager.AllocatorHandle a)
```

### Parameters

**** (\[AllocatorHandle]\(/engine/7000.0/script-reference/unity/collections/allocatormanager/allocatorhandle)): Allocator used for the returned container

### Returns

| Type                                                                                            | Description                  |
| ----------------------------------------------------------------------------------------------- | ---------------------------- |
| [NativeArray\<SystemHandle>](/engine/7000.0/script-reference/unity/collections/nativearray1.md) | An array of system instances |