Exchange/SNA Manual

AWAITIO Procedure
Exchange/SNA System Procedure Calls
5–4 104700 Tandem Computers Incorporated
Considerations You must call AWAITIO to complete a nowait I/O operation. With nowait I/O
operations, control is returned to your program as soon as the operation has started
without waiting for the operation to complete. A subsequent call to AWAITIO
completes the nowait I/O operation and returns the results of the operation to your
program. Note that it is the call to AWAITIO that indicates if the I/O operation
completed successfully, not the call to the procedure that started the I/O operation.
If you are performing wait I/O operations, calls to AWAITIO are not required. With
wait I/O operations, control does not return to your program until each I/O operation
has completed.