Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls (R)
Guardian Procedure Calls Reference Manual—522629-013
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READUPDATELOCK[X] Procedures
READUPDATELOCK[X] Procedures
Summary
Syntax for C Programmers
Syntax for TAL Programmers
Parameters
Condition Code Settings
Considerations
Considerations for READUPDATELOCKX Only
Errors for READUPDATELOCKX Only
OSS Considerations
Example
Related Programming Manuals
Summary
The READUPDATELOCK[X] procedures are used for random processing of records in
a disk file. READUPDATELOCK is intended for use with 16-bit addresses, while
READUPDATELOCKX is intended for use with 32-bit extended addresses. Therefore,
the data buffer for READUPDATELOCKX can be either in the caller’s stack segment or
any extended data segment.
READUPDATELOCK[X] locks, then reads the record from the current position in the
file in the same manner as the combination of LOCKREC and READUPDATE[X].
READUPDATELOCK[X] is intended for reading a record after calling POSITION or
KEYPOSITION, possibly in anticipation of a subsequent call to the WRITEUPDATE[X]
or WRITEUPDATEUNLOCK[X] procedure.
A call to READUPDATELOCK[X] is functionally equivalent to a call to LOCKREC
followed by a call to READUPDATE[X]. However, less system processing is incurred
when one call is made to READUPDATELOCK[X] rather than two separate calls to
LOCKREC and READUPDATE[X].