The system provides a way for programs running in task mode to expand the size of the normal and recovery linkage stacks. The default size for a normal linkage stack is at least 96 entries. A linkage stack of this size is probably sufficient for your program's needs. However, if you have a program, such as one with recursive code, that needs more than 96 entries, you can use the LSEXPAND macro to request a normal linkage stack of up to 16,000 entries.

When a program uses up all of the entries in the normal linkage stack, the system abends the workunit and sets up a recovery linkage stack. The default for this linkage stack is 24 entries. The LSEXPAND macro can increase the recovery linkage stack to 4000 entries.

The timing of the execution of the LSEXPAND macro is important. You must anticipate using up the entries in the stack. If the program has already issued a "stack full" program interruption, the system will not accept the LSEXPAND macro and will abend the workunit. In other words, don't wait until the normal linkage stack is full to issue this macro.

Example of Requesting Larger Normal and Recovery Linkage Stacks

LSEXPAND NORMAL=2000,RECOVERY=150