Pathway/iTS System Management Manual (G06.24+)

Tuning Your System Using Statistics
HP NonStop Pathway/iTS System Management Manual—426748-002
5-4
Memory Management and Allocation
If no terminal tasks are waiting, the TCP sets a timeout value for the dynamic
link—using the value specified with the SET SERVER DELETEDELAY
command—and places the link on the TCP DELINK queue.
The DELETEDELAY parameter specifies the maximum amount of time a link
between a link manager and a dynamic server can remain idle before the link
manager automatically closes the server and informs the PATHMON process.
If the timeout expires, the TCP sends the delink request to the PATHMON process,
which dissolves the link.
Dissolving Links
The TCP dissolves a link as follows:
1. The TCP specifies a timeout value for the link and places the link on the DELINK
queue.
2. After the timeout expires, the TCP removes the link from the DELINK queue and
relays the request to the PATHMON process.
Links can be removed from the DELINK queue to satisfy a request for a link from a
terminal task.
Memory Management and Allocation
When a terminal task is started (via the START TERM or RUN PROGRAM command),
the TCP fetches SCREEN COBOL object code from the disk to its extended data
segment. The TCP uses its extended data segment for the SCREEN COBOL code
segments and for terminal context data. The TCP ensures that the proper code
segments are resident in memory, as needed. Additionally, the TCP allocates buffer
space for I/O operations.
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The TCP allocates memory for storage, data, and code area.
Storage Area
During interpretation of a SCREEN COBOL program, the TCP is responsible for
dynamically allocating and deallocating memory space for terminal and server I/O
buffers.
Each TCP maintains two storage pools in memory: TERMPOOL and SERVERPOOL.
These pools provide buffer space as follows:
•
TERMPOOL
Provides buffer space for I/O operations to terminals.
•
SERVERPOOL
Provides buffer space for I/O operations to servers.