---
title: nullTxHandler
framework: kernel
role: pseudoSymbol
path: kernel/iokerneldebugger/1812684-nulltxhandler
---

# nullTxHandler

Null transmit handler.

## Declaration

```occ
static void nullTxHandler(
 IOService *target, 
 void *buffer, 
 UInt32 length ); 
```

## Overview

Overview This function is registered as the transmit handler when an IOKernelDebugger object surrenders its status as the active debugger nub. Until another IOKernelDebugger object gets promoted, this function will handle polled transmit requests from KDP. This function does nothing useful.

## See Also

### Miscellaneous

- [debugger](kernel/iokerneldebugger/1812543-debugger.md)
- [free](kernel/iokerneldebugger/1812554-free.md)
- [handleClose](kernel/iokerneldebugger/1812560-handleclose.md)
- [handleIsOpen](kernel/iokerneldebugger/1812565-handleisopen.md)
- [handleOpen](kernel/iokerneldebugger/1812573-handleopen.md)
- [init](kernel/iokerneldebugger/1812584-init.md)
- [kdpLinkStatusDispatcher](kernel/iokerneldebugger/1812595-kdplinkstatusdispatcher.md)
- [kdpReceiveDispatcher](kernel/iokerneldebugger/1812607-kdpreceivedispatcher.md)
- [kdpSetModeDispatcher](kernel/iokerneldebugger/1812616-kdpsetmodedispatcher.md)
- [kdpTransmitDispatcher](kernel/iokerneldebugger/1812631-kdptransmitdispatcher.md)
- [lock](kernel/iokerneldebugger/1812643-lock.md)
- [nullLinkStatusHandler](kernel/iokerneldebugger/1812653-nulllinkstatushandler.md)
- [nullRxHandler](kernel/iokerneldebugger/1812663-nullrxhandler.md)
- [nullSetModeHandler](kernel/iokerneldebugger/1812671-nullsetmodehandler.md)
- [powerStateDidChangeTo](kernel/iokerneldebugger/1812705-powerstatedidchangeto.md)
- [powerStateWillChangeTo](kernel/iokerneldebugger/1812727-powerstatewillchangeto.md)
- [registerHandler](kernel/iokerneldebugger/1812741-registerhandler.md)
- [signalDebugger](kernel/iokerneldebugger/1812763-signaldebugger.md)
- [unlock](kernel/iokerneldebugger/1812777-unlock.md)