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# schedule

A scheduling callback for the run loop source. This callback is called when the source is added to a run loop mode. Can be `NULL`.

```
var schedule: ((UnsafeMutableRawPointer?, CFRunLoop?, CFRunLoopMode?) -> Void)!
```

## Parameters

`info`

The `info` member of the [`CFRunLoopSourceContext`](/documentation/CoreFoundation/CFRunLoopSourceContext) structure that was used when creating the run loop source.

`rl`

The run loop in which the source is being scheduled.

`mode`

The run loop mode in which the source is being scheduled.

## Discussion

---

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