---
title: releaseAsyncReference64
framework: kernel
role: pseudoSymbol
path: kernel/iouserclient/1809435-releaseasyncreference64
---

# releaseAsyncReference64

Release the mach_port_t reference held within the OSAsyncReference64 structure.

## Declaration

```occ
static IOReturn releaseAsyncReference64(
 OSAsyncReference64reference); 
```

## Parameters

- `reference`: The reference passed to the subclass IOAsyncMethod, or externalMethod() in the IOExternalMethodArguments.asyncReference field.

## Return Value

Return Value A return code.

## Overview

Overview The OSAsyncReference64 structure passed to async methods holds a reference to the wakeup mach port, which should be released to balance each async method call. Behavior is undefined if these calls are not correctly balanced.

## See Also

### Miscellaneous

- [exportObjectToClient](kernel/iouserclient/1809421-exportobjecttoclient.md)
- [releaseNotificationPort](kernel/iouserclient/1809442-releasenotificationport.md)
- [removeMappingForDescriptor](kernel/iouserclient/1809451-removemappingfordescriptor.md)
- [sendAsyncResult64WithOptions](kernel/iouserclient/1809458-sendasyncresult64withoptions.md)