---
title: ctl_getenqueuespace
framework: Kernel
role: symbol
role_heading: Function
platforms: [macOS 10.13+]
path: kernel/1809173-ctl_getenqueuespace
---

# ctl_getenqueuespace

## Declaration

```occ
errno_t ctl_getenqueuespace(kern_ctl_ref kctlref, u_int32_t unit, size_t *space);
```

## Parameters

- `kctlref`: The control reference of the kernel control.
- `unit`: The unit number of the kernel control instance.
- `space`: The address where to return the current space available

## Return Value

Return Value 0 - Success; the amount of space is returned to caller. EINVAL - Invalid parameters.

## Discussion

Discussion Retrieve the amount of space currently available for data to be sent from the kernel control to the client.

## See Also

### control

- [ctl_deregister](kernel/1809161-ctl_deregister.md)
- [ctl_enqueuedata](kernel/1809168-ctl_enqueuedata.md)
- [ctl_enqueuembuf](kernel/1809171-ctl_enqueuembuf.md)
- [ctl_getenqueuereadable](kernel/2919907-ctl_getenqueuereadable.md)
- [ctl_register](kernel/1809176-ctl_register.md)