OPS/REXX Built-in Functions › OPSENQ Function

OPSENQ Function

This function performs two related classes of operations:

• It interacts with the z/OS ENQ/DEQ services to serialize usage of resources. Any rule or program using the OPSENQ function should use a SIGNAL ON SYNTAX statement to dequeue resources if the rule or program fails to run properly. In this case, OPSENQ returns a numeric value that is the return code from the ENQ or DEQ service.

  Note: Leaving the resources queued can leave your system inoperable.

• It uses the z/OS GQSCAN service to provide information about outstanding resource serialization in the current serialization complex. In this case, OPSENQ returns a positive numeric value that indicates the number of data lines added to the external data queue (EDQ).

Note: The OPSENQ function can be used in OPS/REXX or AOF rules.

The OPSENQ function has the following format:

var = OPSENQ(func [,major][,minor][,type][,scope][,ret])

func

Specify one of the following:

E - To enqueue on a resource

D - To dequeue from a resource

C - To display resource conflicts

Q - To display resources

Note: Functions E and D are related and have a similar set of rules. Functions C and Q are also related but have a different set of rules.

The following arguments apply only to the E and D functions:

major

(Optional) Identifies the major name of the resource, up to eight characters in length. By convention, the major and minor names together identify the resource. If you omit this argument, the default major name is the value of the ENQ parameter that, in turn, has a default value of OPS/MVS.

minor

(Optional) Identifies the minor name of the resource, up to 255 characters in length. If the OPSENQ function was called from an AOF rule, the default minor name is RULEOPxxssssssss.rrrrrrrr, where Opxx is the subsystem name and ssssssss.rrrrrrrr is the name of the rule set and rule that issued the enqueue. In all other cases, the default name is RULEuuuuuuuuppppppppp where uuuuuuuu is the current TSO user ID or job name and ppppppppp is the name of the current REXX program that issued the enqueue.

type

(Optional) Specifies the type of enqueue request, either E for exclusive or S for shared. This argument is not used for dequeue function calls. The default is E.

scope

(Optional) Specifies the scope of the enqueue request. You can specify the following values:

• STEP for a job step-wide enqueue request.
• SYSTEM for a system-wide enqueue request. This is the default.
• SYSTEMS for a systems-wide enqueue request.

ret

(Optional) Specifies the type of return for the enqueue request. This value is one of the following:

• HAVE - Returns control when the enqueue has been obtained (it waits if another user holds the resource). This is the default.
• NONE - Returns control when the enqueue has been obtained.
• TEST - Tests whether the desired enqueue is available immediately but does not enqueue on the resource.
• USE - Enqueues the desired resource only if it is available immediately.

Default: HAVE

The following arguments apply only to the C and Q functions:

major

Identifies the major name of the resource for which you want to obtain information. It may be up to eight characters in length. By convention, the major and minor names together identify the resource. If you omit this argument, the default major name used for the scan is * (that is, all major names).

Note: The major names associated with the C function can be *. However, the Q function requires that either the major names or the minor names must be more specific than a wildcard.

minor

Identifies the minor name of the resource for which you want to obtain information. It may contain up to 255 characters. If you omit this argument, the default minor name used for the scan is * (that is, all minor names).

Note: The minor names associated with the C function can be *. However, the Q function requires that either the major names or the minor names must be more specific than a wildcard.

type

This argument must either be omitted or specified as a single wildcard character *. It is currently used only as a placeholder.

scope

Limits the scan to ENQs with the specified scope. You can specify the following values:

• STEP for job step-wide enqueue requests
• SYSTEM for system-wide enqueue requests
• SYSTEMS for systems-wide enqueue requests
• ALL to scan for all possible scopes

Note: There is no default scope value.

ret

This argument is not applicable to the C and Q functions and must be omitted.