Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (L)

Guardian Procedure Calls Reference Manual—522629-013

8-20

LOCKREC Procedure

Summary

Syntax for C Programmers

Syntax for TAL Programmers

Parameters

Condition Code Settings

Considerations

OSS Considerations

Related Programming Manual

Summary

The LOCKREC procedure excludes other users from accessing a record at the current

position. The “user” is defined either as the opener of the file (identified by

filenum) if

the file is not audited—or the transaction (identified by the TRANSID) if the file is

audited.

For key-sequenced, relative, and entry-sequenced files, the current position is the

record with a key value that matches exactly the current key value. For unstructured

files, the current position is the relative byte address (RBA) identified by the current-

record pointer.

If the record is unlocked when LOCKREC is called, the record becomes locked, and

the caller continues executing.

If the file is already locked by another user, behavior of the system is specified by the

locking mode. There are two “locking” modes available:

•

Default—Process requesting lock is suspended (see “Considerations”).

•

Alternate—Lock request is rejected with file-system error 73. When the alternate

locking mode is in effect, the process requesting the lock is not suspended (see

“Considerations”).

Note. LOCKREC operations cannot be used with queue files.

Note. A call to LOCKFILE is not equivalent to locking all records in a file; that is, locking all

records still allows insertion of new records, but file locking does not. File locks and record

locks are queued in the order they are issued.