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

ENQ. [CALLI 151]
Or, if the ASCIZ string is stored in 7-bit bytes,
starting at the first byte of the location being
referenced, the pointer can take the form:
XWD
-1, address
The ASCIZ string at address can be up to 30
(decimal) words. The maximum string length for
your system is stored in %EQMSS in GETTAB table
.GTENQ.
Cooperating programs (those requesting the same
resources) must specify exactly the same user code
or ASCIZ string.
2 .ENQPS
Specifies
resource,
resource.
O.
either a pool number for a pooled
or a sharer group number for a sharable
This word is optional and defaults to
For a pooled resource, the word contains the
pool-size in the left half and the number of
resources requested from the pool in the right
ha~f. For a sharable resource, the left half is
zero, and the right half contains the sharer-group
number. Thus, a resource cannot be pooled and
also be accessible to a sharer group.
A pooled resource is defined by the first
requestor of the resource. By specifying the
number of resources in the pool, the requestor is
defining the number of "copies" of the resource to
be made available. Each copy of the resource can
be requested for exclusive access by specifying
the same resource identifier in word .ENQBP and
the same pool-size in word .ENQPS. The requestor
must also specify, in the right half of .ENQPS
(EQ.PPR), the number of copies of the resource to
lock.
If the left half of .ENQPS (EQ.PPS) is 0, the
right half (EQ.PPR) specifies the sharer-group
number, thus defining a group of jobs that can
simultaneously share the resource. Any program
that sets the flag EQ.FSR and specifies the same
resource and the same sharer group number will be
granted its request. Therefore, when you share
the ownership of a resource, only other jobs in
the same sharer group are allowed ownership of the
resource. The sharer group number defaults to O.
Therefore, if the first requestor specifies a
sharable resource but omits the sharer group
number, all subsequent sharable requests for the
resource that also omit the sharer group number,
or that set it to 0, will be granted immediately.
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