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Important: The information in this document is obsolete and should not be used for new development.

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Inside Macintosh: Networking /
Chapter 11 - Ethernet, Token Ring, and Fiber Distributed Data Interface / Ethernet, Token Ring, and FDDI Reference
Routines / Writing and Reading Ethernet Packets


ERdCancel

The ERdCancel function cancels execution of a specific call to the ERead function.

FUNCTION ERdCancel (thePBptr: EParamBlkPtr; 
                     async: Boolean): OSErr;
thePBptr
A pointer to a parameter block of type EParamBlock.
async
A Boolean value that specifies whether the function should be
executed asynchronously or synchronously. Specify TRUE for asynchronous execution.
-->ioCompletionProcPtrA pointer to completion routine.
<--ioResultOSErrThe result code.
-->ioRefNumIntegerThe driver reference number.
-->csCodeIntegerAlways ENetRdCancel for this function.
-->ePointerPtrA pointer to ERead parameter block.

Field Description
ePointer
A pointer to the .ENET parameter block that you specified when you called the ERead function that you want to cancel.
DESCRIPTION
To cancel an ERead function request using the ERdCancel function, you must have called the ERead function asynchronously. You specify in the ePointer parameter a pointer to the parameter block that you used when you called the ERead function.

When you call the ERdCancel function, the pending ERead function that you cancel receives the reqAborted result code.

TOKEN RING AND FDDI CONSIDERATIONS
This function is not valid for token ring and FDDI.

ASSEMBLY-LANGUAGE INFORMATION
To execute the ERdCancel function from assembly language, call the _Control
trap macro with a value of ENetRdCancel in the csCode field of the parameter
block. To execute the _Control trap asynchronously, include the value ,ASYNC in
the operand field.

RESULT CODES
noErr0No error
cbNotFound-1102ERead not active

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© Apple Computer, Inc.
7 JUL 1996