Synchronizing Access to Resources › &LOCK Verb

&LOCK Verb

The &LOCK verb lets you obtain and release resource locks.

• &LOCK operates system-wide; it is not restricted to your NCL region alone.
• &LOCK is used to designate a particular resource lock that the procedure wants to control, and specifies the type of control that is required.

If a process has exclusive control of a resource lock, all other processes in the system are prevented from gaining access to the resource at the same time. Alternatively, you might want the process to gain shared access to the resource lock, which prevents any other procedure from being granted exclusive access. If required, you can alter the status of the lock from shared to exclusive, or from exclusive to shared, during processing.

A procedure can also use &LOCK to test whether any other procedure is holding a lock that it needs to access.

For more information about the &LOCK verb, see the Network Control Language Reference Guide.