TOPS-10 Monitor Calls Manual Volume 2 AA-K039D ... - Trailing-Edge

ENQ. [CALLI 151]
1 .ENQRI
2 .ENQTL
An 18-bit request-id identifying this request.
This optional value identifies the ENQ. request,
enabling you to identify it when it causes a
software interrupt. This is useful when you use
the ENQ/DEQ facility in conjunction with the
software interrupt (PSI) system. After an
interrupt is generated, the request-ids of the
granted requests are inclusively ORed into the
status word of the interrupt block. To receive a
software interrupt, use function code 2 (.ENQSI)
when you issue the ENQ. monitor call. The
request-id can also be used with the DEQ. call to
dequeue a specific request.
Time limit specifying the number of seconds to
wait for each request in the call to be granted.
If any resource is not available within that time
limit, the call takes the error return with the
ENQTL% error code in the ac. This word is
optional. If you include the time limit in the
header block, specify 3 for size in word O.
Each lock block represents a separate ENQ. request. There is no
limit to the number of locks that can be requested, but multiple
requests in the same ENQ. call must be given level numbers. The
locks will be granted in the order of the level numbers.
The format of a lock block is shown here and described in more
on the following pages
detail
Word Symbol
o
.ENQFL
1 .ENQBP
2 .ENQPS
3 .ENQMS
4 .ENQTB
Contents
flags+B17+channo
/ flags+user-code \
I user-code I
\ string-pointer /
/ pool-size"number \
\ O"sharer-group /
mask-length"mask-addr
block-length"block-addr
A lock block is two to five words long, identifying the resource to be
locked and describing the characteristics of the lock. The first
requestor of a resource defines lock characteristics. Subsequent
requests for the same resource must conform to those characteristics
or wait until the resource is released by the first requestor.
22-110