ENQ use in CICS

akodakka · New User Joined: 20 May 2010 Posts: 75 Location: India

Hi All

I have checked manuals and previous to get the answer but didn't clear still.

Regarding the resource that we mention in ENQ. As per my understanding the RESOURCE in an ENQ can be a VSAM file , a storage , etc.

The resource that is to be enqueued on must be identified by one of the following methods:

Specifying a data area that is the resource. It is the location (address) of the data area in storage that is important, not its contents. Two tasks, enqueuing on the same resource and using this method, must refer to the same location in storage. They could both, for example, refer to the same location in the Common Work Area (CWA).
EXEC CICS ENQ
RESOURCE(RESNAME)

Specifying a data area that contains a unique character string argument (for example, an employee name) that represents the resource. It is the contents of the data area that is important, not its location. Two tasks, enqueuing on the same resource and using this method, can refer to the same location or different locations, but the contents of the locations must be the same. The length must be supplied in the LENGTH option and can be up to 255 bytes long.
EXEC CICS ENQ
RESOURCE(SOCSECNO)
LENGTH(8)

here my query is ENQ a data area which contains a character string. I have program where i ENQ a resource like

01 WS-RESOURCE PIC X 10 VALUE 'ABCDEFG'

and in my program i am ENQ uing the same

EXEC CICS ENQ
RESOURCE (WS-RESOURCE)
LENGTH(LENGTH OF WS-RESOURCE)
END-EXEC

What will be the relevance of ENQ uing a data string here.? Any thoughts?

Robert Sample · Posted: Fri Nov 30, 2012 9:39 pm

From the description of ENQ in the CICS Application Programming Reference manual, 1.75, with emphasis added by me:

Peter cobolskolan · Posted: Fri Nov 30, 2012 11:19 pm

Normally you dont have use END/DEQ. The END/DEQ can be used when you want to ensure "something" isnt referenced/changed by more than one task at a time e.g. values in CWA, as the CWA is not a "protected resource" in CICS. For files etc the "protection" is handled by CICS without any special programming. This is one of the objectives of a "Transation Processing" system.

dick scherrer · Posted: Sat Dec 01, 2012 12:40 am

Hello,

Why does someone believe you need to implement your own enque?

akodakka · New User Joined: 20 May 2010 Posts: 75 Location: India

Hi all,

Thanks everyone..yes i missed the context highlighted by Robert.

I was doing some research on the CICS API commands by digging through the programs that has been using in my shop.Thanks again..really helped me to understand the ENQ.

I hope i will be able to answer these type of questions in near future:)

Bill O'Boyle · Posted: Sat Dec 01, 2012 2:45 am

If you do need to use an ENQ/DEQ Resource, it would be in your best interest to define the resource-name, using a combination of upper/lower case letters, numeric values, along with special characters in an attempt to make it as unique as possible. EG:

'$@My-Resource-Name-001@$'

Doing this will reduce other creative minds in your shop from duplicating the name.

One last thought; Once you're done with accessing the resource and you're not at task termination, issue a DEQ.