Special fetch and call considerations

You should not recursively fetch and call the fetchable main from within the child enclave; results are unpredictable if you do.

The load module that is the target of the FETCH and CALL is reentrant if all routines in the load module are reentrant. (See Making your application reentrant for more information on reentrancy.)

Language Environment relies on the underlying operating system for the management of load module attributes. In general, multiple calls of the same load module are supported for load modules that are any of the following:

Reentrant
It is recommended that your target load module be reentrant.
Nonreentrant but serially reusable
You should ensure that the main procedure of a nonreentrant but serially reusable load module is self-initializing. Results are unpredictable otherwise.
Nonreentrant and non-serially reusable
If a nonreentrant and non-serially reusable load module is called multiple times, each new call brings in a fresh copy of the load module. That is, there are two copies of the load module in storage: one from FETCH and one from CALL. Even though there are two copies of the load module in storage, you need only one PL/I RELEASE statement because upon return from the created enclave the load module loaded by CALL is deleted by the operating system. You need only release the load module loaded by FETCH.