Technical data

System Dump Analyzer
VALIDATE QUEUE
VALIDATE QUEUE
Validates the integrity of the specified queue by checking the pointers in the
queue.
Format
VALIDATE QUEUE [address] [/qualifier[,...]]
Parameter
address
Address of an element in a queue.
If you specify a period (.) as the address, SDA uses the last evaluated expression
as the queue element’s address.
If you do not specify an address, the VALIDATE QUEUE command determines
the address from the last issued VALIDATE QUEUE command in the current
SDA session.
If you do not specify an address, and no queue has previously been specified,
SDA displays the following error message:
%SDA-E-NOQUEUE, no queue has been specified for validation
Qualifiers
/MAXIMUM_LINKS=nn
Specifies the number of entries in the queue that are to be validated.
/SELF_RELATIVE
Specifies that the selected queue is a self-relative queue.
Description
The VALIDATE QUEUE command uses the forward and backward pointers in
each element of the queue to make sure that all such pointers are valid and
that the integrity of the queue is intact. If the queue is intact, SDA displays the
following message:
Queue is complete, total of n elements in the queue
In these messages, n represents the number of entries the VALIDATE QUEUE
command has found in the queue.
If SDA discovers an error in the queue, it displays one of the following error
messages:
Error in forward queue linkage at address nnnnnnnn after tracing x elements
Error comparing backward link to previous structure address (nnnnnnnn)
Error occurred in queue element at address oooooooo after tracing pppp elements
These messages can appear frequently when the VALIDATE QUEUE command
is used within an SDA session that is analyzing a running system. In a running
system, the composition of a queue can change while the command is tracing its
links, thus producing an error message.
SDA–185