Inside Macintosh: Open Transport /

Chapter 3 - Endpoints / Endpoints Reference

Constants and Data Types

Open Transport Flags

Open Transport uses the OTFlags enumeration to specify additional information about data that is being transmitted. The constant names that Open Transport can return for this field are given by the Open Transport flags enumeration.

typedef UInt32 OTFlags;
enum {
   T_MORE         = 0x001,/* More data to come in message */
   T_EXPEDITED    = 0x002,/* Data is expedited, if possible */
   T_ACKNOWLEDGED = 0x004,/* Acknowledge transaction */
   T_PARTIALDATA  = 0x008,/* Partial data - more coming */
   T_NORECEIPT    = 0x010/* No event on transaction done */
   T_TIMEDOUT     = 0x020/* Reply timed out */
};

Constant descriptions

T_MORE

There is more data for the current TSDU or ETSDU. The next send or receive operation will handle additional data for this TSDU or ETSDU.

T_EXPEDITED

The data is sent as expedited data if the endpoint supports expedited data.

T_ACKNOWLEDGED

The transaction must be acknowledged before the send or receive function can complete.

T_PARTIALDATA

There is more data for the current TSDU or ETSDU. Unlike T_MORE, T_PARTIALDATA does not guarantee that the next send or receive operation will handle additional data for this TSDU or ETSDU.

T_NORECEIPT

There is no need to send a T_REPLY_COMPLETE event to complete the transaction. If you don't need to know when the transaction is actually done, you can set this flag to improve performance.

T_TIMEDOUT

The reply timed out. If a protocol such as ATP loses the acknowledgement for a transaction that needs to be acknowledged, the transaction will eventually time out. Since the reply didn't really fail (it just timed out), Open Transport can send a T_REPLY_COMPLETE event to complete the transaction and set this flag to explain what happened.