tcl.unlock-group Verb: Access/TCL

tcl.unlock-group

Command tcl.unlock-group Verb: Access/TCL
Applicable release versions: AP
Category TCL (746)
Description clears group locks.

This is capable of clearing all types of group locks or specific types of locks, such as: update group locks, retrieval group locks, or locks on file control blocks.

Group locks provide a means of assuring data reliability by preventing two processes from attempting to update the same group at the same time.

Many processes within the system set group locks. For instance, the "save" processor locks a group while it is being saved.

The "read" statements (in Pick/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 Pick systems, which only set group locks on "read" statements. The "locked" clause in the "read" statements allow a graceful means of dealing with the situation of attempting to access a locked item. The program can take a special path and indicate to the operator that they should "try again later."
Syntax unlock-group {.}fid{-{.}end.fid} {(options)}
Options fid{-end.fid} Used only when the fid(s) is specified in options string. The fid is implied as a decimal number unless it is preceded by a period, in which case it is considered to be a hexadecimal reference.

f Releases group locks placed on file control blocks only.

i Suppresses the "Group 'x' released" message.

o Releases read-only locks only.

r Releases retrieval group locks only.

u Releases update group locks only.
Example
unlock-group 15000

Unlocks the group at (decimal) fid 15000

unlock-group .3A98

Unlocks the group at (hexadecimal) fid 3A98 (15000 in decimal)

unlock-group (f

Unlocks FCB's only.

unlock-group 15010-15020

Unlocks groups between (and including) (decimal) fids 15010 through 15020.
Purpose
Related tcl.list-lock-queue
tcl.unlock-item
locking.scheme
basic.matread
tcl.clear-basic-locks
tcl.list-lockq
basic.release
tcl.clear-locks
tcl.what
tcl.list-locks_rp
tcl.where