MPE/iX 5.5 Operating System Limits

Item Limit Description Resource Table
1 2047 CM Code Segments (Loaded CM Libraries) Code Segment Table
1 255 CM Code Segments (Physically Mapped) Code Segment Table
2 255 CM Code Segments Per Loaded Program File Code Segment
Table Extension
3 519 Loaded Unique CM Program Files CST Block DST
4 (See text) Loaded CM Programs (& LOADPROCs) LST DST
5 ~22771 Loaded Unique NM Program Files (No XLs) Loaded File Table
5 ~90 Loaded Unique NM Pgms (1 Unique XL/PGM) Loaded File Table
6 88 NM User Libraries per Process PFL
6 ~10000 SG Data Exports/Process (75 avg imp/exp) PFL
(1) Code segment table - KSO253
The Code Segment Table (CST) is used to manage Compatibility Mode (CM) code
segments which are a part of a Segmented Library (SL). There are 255 entries reserved
for physically mapped segments. Physically mapped segments are reserved for use by the
system. These typically reside in SL.PUB.SYS. The remaining entries are available for
user library segments. These are referred to as logically mapped segments.
A CST entry is allocated whenever an SL segment is loaded for the first time. This occurs
when:
- A CM program is executed via the :RUN command with the ;LIB= option.
- SL segments are :ALLOCATEd.
- A procedure (in an SL) is loaded via the LOADPROC intrinsic.
CST entries are shared. Loading an SL segment after the first time will not result in the
allocation of a CST entry. Share counts on segments are maintained in the Loader
Segment Table (LST). The share count for a segment is decremented when the segment is
unloaded. When the share count for a particular segment drops to zero, the CST entry for
that segment is released.
The CST table limits the number of compatibility mode library segments.
(2) Code segment table ext
The Code Segment Table Extension (CSTX) is used to manage Compatibility Mode
(CM) code segments which are a part of a CM program. There is one CSTX for each CM