MPE/iX 5.5 Operating System Limits

program that is loaded or :ALLOCATEd. Each CM program can reference up to 255
logically mapped segments. Logically mapped segments include those that are a part of
the program file and any user SL segments that are referenced. Each logically mapped
segment that is a part of the program file will use an entry in the processes' CSTX.
Logically mapped user SL segments will count toward the maximum number of 255
logically mapped segments, but will use CST entries instead of CSTX entries.
This table limits the number of logically mapped compatibility mode segments in any
program file to 255.
(3) CST block DST - DST035
The CST Block table contains a pointer to the CSTX object for each CM program that is
loaded or allocated. An entry is used whenever a program is loaded or :ALLOCATEd for
the first time. The entry is deallocated when the program is terminated for the last time or
when the program is :DEALLOCATEd.
This table limits the number of concurrently running CM programs to 519.
(4) Lst DST - DST018
There is an SL File entry in the LST for every loaded SL (including SL.PUB.SYS). These
entries are deleted when all SL segments are unloaded. An SL File entry may expand if it
was previously loaded and an unloaded segment is loaded. There is a Program File entry
for every loaded/allocated program file. These entries are deleted when all processes
running the file terminate and it is no longer allocated. There is a Sharer entry for every
process running a CM program file. These entries are deleted when the process
terminates. Loading, Waiter, and Loaded entries are created and deleted during the
load/allocate of a program file. Extension and Loadproc Master entries are normally
stored in the LSTX DSTs. However, during a LOADPROC operation, they are created in
the LST before being transfered to the LSTX. (Switching to CM by name causes a
LOADPROC operation to occur.) The maximum size of the LST is #65528 bytes. As the
entry size is variable, here is the LST internal description you may use to evaluate the
number of entries used. The LST is made up of two parts: a fixed-sized area for overhead
information and a variable-sized area for directory entries. The overhead area is #197 CM
words in size at the beginning of the LST. The LST directory entries are variable in size
(size in CM words, includes 3 word overhead):