# GetOrCreateSystem

> Retrieve the handle for the instance of a system of type T from the current World. If the system does not exist in this World, it will first be created.

## Definition

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

## GetOrCreateSystem\<T>()

Retrieve the handle for the instance of a system of type `T` from the current World. If the system does not exist in this World, it will first be created.

```csharp
public SystemHandle GetOrCreateSystem<T>() where T : ComponentSystemBase
```

### Returns

| Type                                                                           | Description                                                                                                                         |
| ------------------------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------- |
| [SystemHandle](/engine/7000.0/script-reference/unity/entities/systemhandle.md) | The handle for the instance of system type `T` in this World. If the system does not exist in this World, it will first be created. |

### Remarks

**Important:** This function creates a sync point if a system is created, which means that the EntityManager waits for all currently running Jobs to complete before creating the system, and no additional Jobs can start before the function is finished. A sync point can cause a drop in performance because the ECS framework may not be able to make use of the processing power of all available cores.

## GetOrCreateSystem(Type)

Retrieve the handle for the instance of a system of type `type` from the current World. If the system does not exist in this World, it will first be created.

```csharp
public SystemHandle GetOrCreateSystem(Type type)
```

### Parameters

**** (\[Type]\(https\://learn.microsoft.com/dotnet/api/system.type)): The system type

### Returns

| Type                                                                           | Description                                                                                                                            |
| ------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------- |
| [SystemHandle](/engine/7000.0/script-reference/unity/entities/systemhandle.md) | The handle for the instance of system type `type` in this World. If the system does not exist in this World, it will first be created. |

### Remarks

**Important:** This function creates a sync point if a system is created, which means that the EntityManager waits for all currently running Jobs to complete before creating the system, and no additional Jobs can start before the function is finished. A sync point can cause a drop in performance because the ECS framework may not be able to make use of the processing power of all available cores.

## GetOrCreateSystem(SystemTypeIndex)

Retrieve the handle for the instance of a system of type `type` from the current World. If the system does not exist in this World, it will first be created.

```csharp
public SystemHandle GetOrCreateSystem(SystemTypeIndex type)
```

### Parameters

**** (\[SystemTypeIndex]\(/engine/7000.0/script-reference/unity/entities/systemtypeindex)): The system type

### Returns

| Type                                                                           | Description                                                                                                                            |
| ------------------------------------------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------- |
| [SystemHandle](/engine/7000.0/script-reference/unity/entities/systemhandle.md) | The handle for the instance of system type `type` in this World. If the system does not exist in this World, it will first be created. |