The unlock-item BASIC program clears item locks that have not cleared through usual system operation.
Item locks are set by BASIC read statements and other mechanisms, and provide a means of assuring data reliability by preventing two processes from attempting to update the same item at the same time.
The read statements (in BASIC) that have a locking form set item locks only while working with an item. This means that two processes can access items in the same group, provided they do not attempt to update the same item. This is in contrast to early D3 systems, which only set group locks on read statements.
A locked clause in read statements allows a graceful means of dealing with the situation of attempting to access a locked item. The program can take a special case and indicate to the operator that they should try again later.
When a process attempts to access an item that is locked, the screen freezes and starts beeping. Usually, there is only a brief wait until the item is unlocked, at which time the terminal stops beeping and is granted access to the item.
Other times, however, the locking system does not unlock the item for whatever reason (for example, aborts, programming errors, log offs, and so on). It is in cases such as this, and only in these cases, that this command should be used.
Syntax
unlock-item file.reference {item.list*} {(options} |
Parameter(s)
options |
start.port#{-end.port#} |
Used only when a FID is specified in the options string. The FID is implied as a decimal number unless it is proceeded by a period, where it is then considered to be a hexadecimal reference. |
i |
Suppresses message item 'x' released. |
Example(s)
Displays the current item locks.
list-locks (i |
||||||
Item |
Locks |
PIB# |
Lvl |
Hash |
item-ID |
Filename |
29198 |
(00720E) |
33 |
2 |
2D52 |
33109 |
cx |
29003 |
(00714B) |
7 |
1 |
2C8E |
32914 |
cx |
234034 |
(039232) |
86 |
0 |
1923 |
record2 |
doc |
179222 |
(02BC16) |
25 |
0 |
248A |
74845480 |
entity |
234034 |
(039232) |
89 |
0 |
404B |
accounts |
doc |
169528 |
(029638) |
35 |
1 |
6432 |
110462 |
entity |
71998 |
(01193E) |
12 |
0 |
7250 |
8462 |
action |
79366 |
(013606) |
79 |
0 |
04A4 |
kr |
tcl-stack |
Unlocks the item shown.
unlock-item action 8462 [454] Item ’8462’ unlocked. |
See Also
clear-basic-locks Macro, clear-locks Command, list-lockq Command, lock Statement, Locking Scheme, matread Statement, readv Statement, release Statement, unlock-group Command, what Command