GDSX (Extended General Device Support) Manual
Design and Development
Extended General Device Support (GDSX) Manual—529931-001
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MAXIOCBPOOL
MAXIOCBPOOL
This static parameter can be used to override the calculation of IOCB pool space done
automatically by TSCODE during process initialization. In general, you should not
need to set this parameter.
The size that TSCODE calculates for the pool can be overridden by using a TACL
PARAM command to assign a value to the external name MAXIOCBPOOL, or by
assigning a value to the internal DEFINE name in the USER^INIT^CONFIG^PARAMS
user exit. TSCODE uses the user-specified setting unless it is determined that the
pool size would be insufficient, in which case TSCODE uses the value that it
calculated.
If the pool size specified by this parameter is too large (more than 131,064 bytes), or if
the size causes the running total calculated for control block pools, the extended buffer
pool, and the extended message pool to exceed 16,777,216 bytes, an error message
is sent to the home terminal, and the GDSX process stops with abend error 020. The
configuration error message is:
10003 maxIOCBpool or previous pools too large.
TSCODE allocates an IOCB pool from extended memory. (See iocb^template in the
DCCBDECS file in Appendix C.) The size in bytes of the IOCB pool is calculated as
follows:
IOCB pool size = $LEN(IOCB^TEMPLATE) * MAXIOCBS
MAXIOCBS
This static parameter specifies the maximum number of nowait I/O operations that can
be outstanding at one time.
MAXITC
This static parameter specifies the maximum number of DEVICE^HANDLER tasks that
communicate with each other by ITC messages. If LINE^HANDLER tasks are to be
created, TSCODE increases the MAXITC value assigned by you to accommodate
other needed ITC files.
Internal DEFINE
Name
CONFIG^PARAMS
Name Default Value Range
maxiocbpoolsize maxiocbpool^size (see following
equation)
Up to 131,064 bytes
Internal DEFINE Name CONFIG^PARAMS Name Default Value Range
maxiocbs maximum^iocbs 128 I/Os 128–2047 I/Os
Internal DEFINE Name CONFIG^PARAMS Name Default Value Range
maxitc max^itc 0 0–1020 tasks