If more than one user will run an application program at the same time (for example, users in different address spaces accessing a program that resides in the link pack area), you must make the program reentrant by compiling with the RENT option.
You do not need to worry about multiple copies of variables. The compiler creates the necessary reentrancy controls in the object module.
The following Enterprise COBOL programs must be reentrant:
For reentrant programs, use the DATA compiler option and the HEAP and ALL31 runtime options to control whether dynamic data areas, such as WORKING-STORAGE, are obtained from storage below or above the 16-MB line.
related concepts
Storage and its addressability
related references
RENT
DATA
Language Environment Programming Reference (ALL31, HEAP)