NM and CM callable.
Dynamically locks a file. If dynamically locking more than one
RIN, multiple RIN (MR) capability is required.
Condition Codes |
 |
The following condition codes are possible when lockflag bit
(15:1)=1:
- CCE (2)
Request granted.
- CCG (0)
Not returned.
- CCL (1)
Request denied. This file was not opened with the dynamic
locking aoption bit (10:1) specified in
the FOPEN/HPFOPEN intrinsic, or there was an attempt to
lock more than one RIN and the calling process does not have multiple
RIN (MR) capability.
The following condition codes are possible when lockflag bit
(15:1)=0:
- CCE (2)
Request granted.
- CCG (0)
Request denied. The file was locked by another process.
- CCL (1)
Request denied. This file was not opened with the dynamic
locking aoption bit (10:1) specified in
the FOPEN/HPFOPEN intrinsic, or there was an attempt to
lock more than one RIN and the calling process does not have multiple
RIN (MR) capability.
Operation Notes |
|
On MPE/iX when a file is created (opened as a new file) with dynamic
locking only one accessor (the creator) is allowed. A subsequent call to
FLOCK against such a file (although unnessary) will succeed
because the dynamic locking
bit is not set to zero. On MPE V, when a new file is created with
dynamic locking the the dynamic locking bit is set to zero. For this
reason, a subsequent call to FLOCK will fail on MPE V.
Accessors that have opened a file with the dynamic locking option
enabled must access the file through the FLOCK
intrinsic to gain exclusive access to the file. Since the use of
this intrinsic is discretionary, however,
all accessors must agree to use FLOCK when writing
to a file to guarantee exclusive access. File locking is advised, but
is not mandated by MPE/iX.
