---
title: updateOutputMasterPlug
framework: kernel
role: pseudoSymbol
path: kernel/iofirewirepcrspace/1813299-updateoutputmasterplug
---

# updateOutputMasterPlug

Updates the value of the primary output plug (simulating a lock transaction).

## Declaration

```occ
virtual IOReturn updateOutputMasterPlug(
 UInt32oldVal,
 UInt32newVal); 
```

## Parameters

- `oldVal`: Value returned by doc://com.apple.documentation/documentation/kernel/iofirewirepcrspace/1556234-readoutputmasterplug.
- `newVal`: new value to store in plug if it’s current value is oldVal.

## See Also

### Miscellaneous

- [allocateInputPlug](kernel/iofirewirepcrspace/1813120-allocateinputplug.md)
- [allocateOutputPlug](kernel/iofirewirepcrspace/1813128-allocateoutputplug.md)
- [clearAllP2PConnections](kernel/iofirewirepcrspace/1813138-clearallp2pconnections.md)
- [freeInputPlug](kernel/iofirewirepcrspace/1813150-freeinputplug.md)
- [freeOutputPlug](kernel/iofirewirepcrspace/1813163-freeoutputplug.md)
- [getPCRAddressSpace](kernel/iofirewirepcrspace/1813173-getpcraddressspace.md)
- [init](kernel/iofirewirepcrspace/1813189-init.md)
- [readInputMasterPlug](kernel/iofirewirepcrspace/1813201-readinputmasterplug.md)
- [readInputPlug](kernel/iofirewirepcrspace/1813218-readinputplug.md)
- [readOutputMasterPlug](kernel/iofirewirepcrspace/1813228-readoutputmasterplug.md)
- [readOutputPlug](kernel/iofirewirepcrspace/1813239-readoutputplug.md)
- [setAVCTargetSpacePointer](kernel/iofirewirepcrspace/1813255-setavctargetspacepointer.md)
- [updateInputMasterPlug](kernel/iofirewirepcrspace/1813265-updateinputmasterplug.md)
- [updateInputPlug](kernel/iofirewirepcrspace/1813280-updateinputplug.md)
- [updateOutputPlug](kernel/iofirewirepcrspace/1813322-updateoutputplug.md)