IBM AS/400 manual Commitment Control Locks, Using Commitment Control, Abridged for

Using Commitment Control

for	commitment		control	before	you	issue	the STRCMTCTL		command, the opening
of	the	file	will fail.
The	CL	command	ENDCMTCTL	notifies	the	system	that	your	activation group or
job has finished processing files under commitmentCL controlReference. See the
(Abridged)for			further information			on the	STRCMTCTL	and	ENDCMTCTL com-
mands.

Commitment Control Locks

On the STRCMTCTL command, you specify a level of locking, either LCKLVL(*ALL), LCKLVL(*CHG), or LCKLVL(*CS). When your program is operating under commitment control and has processed an input or output operation record in a file under commitment control, the record is locked by co control as follows:

¹ Your program can access the record.

¹Another program in your activation group or job, with this file unde

control, can	read	the record. If the file is a shared file, th
also update	the	record.

¹Another program in your activation group or job that does not have

under commitment control cannot read or update the record.

¹Another program in a separate activation group or job, with this fi mitment control, can read the record if you specified LCKLVL(*CHG), b

cannot read the

record

if

you

specified

LCKLVL(*ALL).

With

either

lo

the

next

program

cannot update

the

record.

¹

Another

program that

does

not

have

this

file

under commitment

control

is

not

in

your

activation

group

or

job

can

read but

not

update

th

¹

Commitment

control

locks

are

different

than

normal

locks,

depend

on the

LCKLVL specified, and can only be released by the COMMIT and ROLBK operations.

The COMMIT and ROLBK operations release the locks on the records. The UNLOCK operation will not release records locked using commitment control. theCL Reference (Abridged)for details on lock levels.

The	number		of	entries that can be locked under commitment control befor
COMMIT	or	ROLBK		operations are	required may		be	limited. For		more	inform
see theBackup and Recoverymanual.
Note:	The	SETLL		and SETGT operations will lock		a	record in		the	same	cases
	where		a	read operation	(not for	update)		would	lock a	record fo
	control.

Commitment Control

Scoping

When

commitment

control

is

started

by

using the

STRCMTCTL

command, the

system createscommitmenta definition

. A commitment definition contains infor-

mation

pertaining

to

the

resources being changed under commitment control

that

job.

Each

commitment

definition

is

known

only

to the job that issue

STRCMTCTL

command and

is

ended

when

you

issue

the

ENDCMTCTL

command.

The scope

for

commitment

definition

indicates

which

programs within

the

that

commitment

definition.

A

commitment

definition

can

be scoped at

the

group

level

or

at

the job

level.

308 ILE RPG for AS/400 Programmer's Guide