If the CSECT produced by assembling the space tuning CSECT IGZETUN is detected
in a load module, a warning-level message is issued and the CSECT is not used.
Other Language Environment facilities
provide storage management capabilities at run time instead of link-edit time.
Note: For applications using IGZETUN, see
Using CEEWUCHA for
details on how to suppress the warning-level message and the overhead of writing
it to the
Language Environment MSGFILE.
This is accomplished by using the following five storage management runtime
options:
- HEAP
- Manages heap storage for user
data such as WORKING-STORAGE, EXTERNAL data, and EXTERNAL file information.
- ANYHEAP
- Manages heap storage for
use by Language Environment and
COBOL library routines, which can be located anywhere and used for control
blocks.
- BELOWHEAP
- Manages heap storage for
use by Language Environment and
COBOL library routines, which is located below the 16-MB line and used for
control blocks and I/O buffers.
- STACK
- Manages
stack storage for use by Language Environment,
COBOL data items in the LOCAL-STORAGE SECTION, and COBOL library routines,
which can be used for DSAs (dynamic storage areas).
- LIBSTACK
- Manages stack storage for
use by Language Environment and
COBOL library routines, which is located below the 16-MB line and used for
DSAs.
The RPTSTG runtime option provides
the optimum values to use when specifying the storage management options.
(You will need to first use the RPTSTG option to generate a report of storage
used in your program or run unit. You can then use this report to determine
the values that you need to specify in the five Language Environment storage
options in order to achieve the space tuning purpose.)
Do not use the values from IGZTUNE when specifying the Language Environment tuning
options. These values might not be optimal for tuning storage usage within
the Language Environment environment.
For recommended Language Environment storage
option settings, see Set recommended default Language Environment runtime options.