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

ENQ. [CALLI 151]
-2 .EQFGL The lock you are
requesting is a
global lock.
Specifying this
code prevents
access to the
resource from any
other job. To
use this code,
your job must
have JP.ENQ set
in its privilege
word.
-1 .EQFJB The lock is a
job-wide lock,
preventing access
to the resource
from any other
requests by your
job.
1 .ENQBP
Specifies the resource to be locked. You can use
a pointer to an ASCIZ string, or a user-code in
this word (more on this later). You must include
this word in every lock block because it defines
the resource you are requesting.
When the first program to request the resource is
granted a lock, it is said to have ownership of
the resource. When a second program makes an ENQ.
call with the same value in this word (if a
user-code is specified) or the same ASCIZ string
(if a byte pointer is used), the request is for
the same resource that was granted to the first
job.
The contents of the word to which the byte pointer
refers, or the user code itself, are purely
arbitrary values to the monitor. The monitor only
checks lock requests for matches, granting or
preventing locks on the basis of matching strings.
This is the key to the ENQ/DEQ access-checking
mechanism.
If the flag EQ.FCW is set in the previous word
(.ENQFL), .ENQBP must contain a 36-bit value as a
user-code.
If EQ.FCW is not set, and the flag EQ.BUC is set
in .ENQBP (that is, a value of 5 is placed in bits
0-2), the rest of the word must contain a j3-bit
user-code.
If neither flag is set, this word (.ENQBP) must
contain a pointer to an ASCIZ text string. This
may be either a standard byte pointer in the form:
POINT 7,address,bit-Iocation
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