Requirements for CMIP application programs

An application program that uses the API must fulfill the following requirements:

The API must be called from the home address space.
The application program must be authorized.
The application program must use a task mode of the task control block (TCB).
The read queue exit routine is called under the same TCB that issued the MIBConnect function. An application program with multiple tasks can issue the following API functions from any of its tasks:
- MIBSendRequest
- MIBSendResponse
- MIBSendRegister
- MIBSendDeleteRegister
- MIBSendCmipRequest
- MIBSendCmipResponse
However, the application program must be prepared to handle the invoking of the read queue exit routine from the task that originated the MIBConnect function.
The MIBConnect and MIBDisconnect functions must be called from the same task.
The application program must define the APPL definition statement and specify the name that is to be used on the MIBConnect function. See z/OS Communications Server: SNA Resource Definition Reference for more information about the APPL definition statement.
- A separate APPL definition statement is needed for each MIBConnect function that the application program is expected to perform. The application program cannot call the MIBConnect function again without calling the MIBDisconnect function first.
- Each successful call to the MIBConnect function that specifies the data space vector parameter causes a new data space to be created. For more information about the MIBConnect function, see MIBConnect—MIB connection function.
No API functions can be issued from the TPEND exit routine or the read queue exit routine.

Calls to API functions can be made from more than one subtask. However, the application program is assumed to be terminated when the subtask that issued the MIBConnect function terminates. When the task that issued the MIBConnect function terminates, the ACB for the application program is closed automatically.

The ACB is not closed automatically if multiple tasks are used and a subtask that meets the following conditions terminates:

The subtask is using the API.
The subtask did not open the connection with the MIBConnect function.