The ISOLATED procedure attribute specifies that when a procedure runs on a different process stack than the stack that declares the procedure, it is protected from DS (Discontinue) and ST (Stop) commands that are applied to the second stack.

The stack that declares the procedure is the task or library started when the code file containing the procedure code is initiated. In library procedures, this stack is called the library stack.

Since an isolated procedure can cause DS and ST commands to be delayed, ensure that the isolated procedure runs quickly and efficiently without consuming excess system resources.

For a full description of isolated procedures, refer to Using Isolated Procedures in Libraries in Using Libraries.