---
title: releaseNotificationPort
framework: kernel
role: pseudoSymbol
path: kernel/iouserclient/1809442-releasenotificationport
---

# releaseNotificationPort

Release the mach_port_t passed to registerNotificationPort().

## Declaration

```occ
static IOReturn releaseNotificationPort(
 mach_port_treference); 
```

## Parameters

- `reference`: The mach_port_t argument previously passed to the subclass implementation of registerNotificationPort().

## Return Value

Return Value A return code.

## Overview

Overview The mach_port_t passed to the registerNotificationPort() methods should be released to balance each call to registerNotificationPort(). Behavior is undefined if these calls are not correctly balanced.

## See Also

### Miscellaneous

- [exportObjectToClient](kernel/iouserclient/1809421-exportobjecttoclient.md)
- [releaseAsyncReference64](kernel/iouserclient/1809435-releaseasyncreference64.md)
- [removeMappingForDescriptor](kernel/iouserclient/1809451-removemappingfordescriptor.md)
- [sendAsyncResult64WithOptions](kernel/iouserclient/1809458-sendasyncresult64withoptions.md)