Natural provides locking mechanisms that prevent concurrent updating of Natural source objects. These mechanisms allow the locking of source objects that are edited in a local z/OS environment and/or in a SPoD (Natural Single Point of Development) environment connected to a z/OS server.
You can activate or deactivate different object locking mechanisms by using the profile
parameter SLOCK (see
also the Parameter Reference):
Locking in Local and SPoD EnvironmentsSLOCK=PRE activates locking of source objects that are edited
either locally or in a SPoD environment, or using Natural ISPF, or in mixed
environments.
SLOCK=PRE is the recommended setting when working in mixed
environments.
Locking in SPoD Environments
The default setting SLOCK=SPOD activates object locking only in
a SPoD environment. A source object is then only locked when it is edited using Natural
Studio. For further information, see Object Locking in the section
Remote Development using SPoD in the Natural for
Windows documentation.
In a SPoD environment, SLOCK=SPOD provides compatibility with
previous Natural Versions that supported locking under SPoD.
Checking for Latest Modification
When setting SLOCK=POST, the source object which is being edited
can be read into the source work area and modified by multiple users. However, only the
user who saves a modification first can update the source object. This is done by
comparing the time stamp of the source object stored in the database with the time stamp
of the source object when it is read into the source work area. All other users receive
appropriate error messages when trying to save the source. This is not compatible with
the SPoD locking concept of previous Natural versions.
Locking DeactivatedSLOCK=OFF deactivates all locking mechanisms.
The principles of object locking with profile parameter SLOCK=PRE
set in a local environment are described in the following sections.
The sources of the following types of Natural object are locked while they are being edited with the appropriate Natural editor:
Program
Subprogram
Subroutine
Copycode
Helproutine
Text
Map
Local data area
Global data area
Parameter data area
DDM (data definition module)
Function
When you invoke a Natural editor, the source contained in the source work area will be locked. If the source object you want to edit has already been locked by another user (as indicated by an appropriate message), the source can be displayed in the editor but without an object name at the top of the screen. If you modify the source and want to keep the modifications, you have to save the source as a new source object with a new name.
Note
Reading in a source into the source work area by using the
READ command does not lock the source object. A
source object is only locked when you invoke the Natural editor.
You cannot save (SAVE and STOW
commands) a source that is being locked by another user.
A locked source object contained in the source work area is unlocked when you do any of the following:
clear the source work area,
read in the source of another source object into the source work area,
log on to another library,
terminate the Natural session,
leave the Natural editor while the Leave Editor with Unlock option is set in the editor profile (see also General Defaults in Editor Profile in the section General Information). This option determines whether the source contained in the current source work area is unlocked when leaving the editor. This also applies to maps and DDMs.
You can use the UNLOCK system command (see the System
Commands documentation) to view locked source objects or unlock them if
required.
Object locking is also considered when using the system command
DELETE or RENAME, the Object
Handler or the utility SYSMAIN.
When you move, delete, rename or replace a source object, the locking state of the object is checked:
When the source object is locked, command execution is rejected.
When the source object is not locked, the command is executed.
The utilities SYSRPC, SYSPARM and SYSERR do not support object locking.
