---
title: IODataQueueMemory
framework: IOKit
role: symbol
role_heading: Type Alias
platforms: [iOS 16.0+, iPadOS 16.0+, Mac Catalyst 13.0+, macOS 10.0+, visionOS 1.0+]
path: iokit/iodataqueuememory
---

# IODataQueueMemory

A struct mapping to the header region of a data queue.

## Declaration

```swift
typealias IODataQueueMemory = _IODataQueueMemory
```

## Discussion

Discussion This struct is variable sized. The struct represents the data queue header information plus a pointer to the actual data queue itself. The size of the struct is the combined size of the header fields (3 * sizeof(UInt32)) plus the actual size of the queue region. This size is stored in the queueSize field.