GDSX (Extended General Device Support) Manual

Design and Development
Extended General Device Support (GDSX) Manual—529931-001
2-27
Checkpointing Memory Pool Buffers
Before issuing a call to GETEXTPOOL[X] for space in this pool, the maximum size of
the private extended pool is established by setting the TASKPOOLSIZE configuration
parameter (see GDSX Configuration Parameters on page 2-46). TASKPOOLSIZE
specifies the maximum pool size (in words) that each user task is allowed to acquire
privately. TSCODE calculates an extended memory requirement of total size
(TASKPOOLSIZE * 2) * MAXTASKS bytes for all the private extended pools. The
default for TASKPOOLSIZE is 128 words. TSCODE will allocate this pool unless the
total for all the areas to be allocated in this extended segment exceeds 16,777,216
bytes, in which case configuration error message 10012 is sent to the home terminal:
10012 Sum of final EXT. MEM size > 16777216d
Extended Buffer Pool
This pool may be used as desired. Memory allocated from this pool is byte
addressable. The GETEXTPOOL[X] and PUTEXTPOOL procedures are used to
allocate and deallocate space from this pool.
The maximum size of the extended buffer pool can be established by setting the
MAXBUFPOOL configuration parameter (see GDSX Configuration Parameters on
page 2-46). The default for MAXBUFPOOL is 32,000 bytes, and the maximum is
7.5 megabytes. If the size specified for the extended buffer pool is too large,
configuration error message 10002 is sent to the home terminal:
10002 maxTCBpool or Buffer/Msg pool too large
Extended Message Pool
This pool may be used as desired. Memory allocated from this pool is byte
addressable. The GETEXTPOOL[X] and PUTEXTPOOL procedures are used to
allocate and deallocate space from this pool.
The size of the extended message pool can be established by setting the
MAXMSGPOOL configuration parameter (see GDSX Configuration Parameters on
page 2-46). The default for maxmsgpoolsize is 32,000 bytes, and the maximum is 7.5
megabytes. If the size specified for the extended message pool is too large,
configuration error message 10002 is sent to the home terminal:
10002 maxTCBpool or Buffer/Msg pool too large
Checkpointing Memory Pool Buffers
A call to ^CHECKPOINT(2) checkpoints all local and extended memory pool buffers
acquired by the calling task. If USCODE has allocated an extended segment (with an
ID in the range from 0 to 1023) through calls to ALLOCATESEGMENT and
USESEGMENT, such a segment is not checkpointed with a call to ^CHECKPOINT(2).
Because user tasks share the memory pools and would overwrite each other’s data if
they were allowed to checkpoint directly across to corresponding memory pools in the
backup process, pool buffers are checkpointed to a section of the backup process’s