BPXWDYN - assembler dynamic allocation

Pankaj Gupta · New User Joined: 07 May 2008 Posts: 32 Location: Bangalore

Hello,
I am trying to dynamically allocating a file in assembler.

Here is another way:

Bill Dennis · Posted: Mon Oct 13, 2008 9:13 pm Post subject:

You include a DCB and do an OPEN on the file.

Pankaj Gupta · New User Joined: 07 May 2008 Posts: 32 Location: Bangalore

It cannot be this simple. If I am doing that then the program simply thinks there shoul dbe a DD statement in the JCLs.

But I am dynamically allocating and so somehow I am needing to link the DD name in the OPEN with what BPXWDYN has been allocating.

Bill Dennis · Posted: Mon Oct 13, 2008 9:26 pm Post subject:

That is exactly what dynamic allocation is about. Allocating a file without JCL, but just as if it were in the JCL.

Bill Dennis · Posted: Mon Oct 13, 2008 9:28 pm Post subject:

I see in your other post you are confused on the DDNAME. In your example, change FI(DDNAME) to the ddname you wish to use, ex. FI(CARDIN)

You want to give a ddname, not let one be returned.

Pankaj Gupta · New User Joined: 07 May 2008 Posts: 32 Location: Bangalore

Yes, indeed, I am wanting to give a DD name. DDNAME is being a valid DD name. In fact in my program I am using a DD name other than DDNAME, I just changed it to DDNAME for the purpose of the posting.

the question is still remaining, hjow is the assembler program knowing that my OPEN (DDNAME) is the DDNAME I am providing to the BPXWDYN. The assembler program is naturally expecting DDNAME to being part of a DCB... and then when I am running it is expecting DDNAME to being in the JCLS.

In PL1 I have done this and it is working very perfectly.

Bill Dennis · Posted: Tue Oct 14, 2008 7:02 pm Post subject:

I don't know how else to explain this.

1. Do the dynamic allocation using your desired DDname, for ex. FI(CARDIN)
2. Your program includes a DCB macro INREC DCB DDNAME=CARDIN,.....
3. You do an OPEN for the DCB just as if the DD were in the JCL OPEN (INREC,(INPUT))

Robert Sample · Posted: Tue Oct 14, 2008 7:18 pm Post subject:

Pankaj Gupta · New User Joined: 07 May 2008 Posts: 32 Location: Bangalore

Bill and Robert,
What you are saying is what I would expect to be happening. But this is not what is happening. When I am running the program it is getting the SOC1 because the DD name is missing from the JCL.

Here is the small program:

Robert Sample · Posted: Tue Oct 14, 2008 7:58 pm Post subject:

Just for curiosity, where in your code are you checking the return code of the BPXWDYN link to ensure that BPXWDYN actually did allocate the DDNAME? If the LINK failed, the OPEN will fail and probably with an S0C1 since the link failing means there's probably no DDNAME defined to OPEN.

And Abend-Aid doesn't know you're doing a dynamic allocation, so it assumes your DDNAME will be in the JCL. It doesn't have to be; if the LINK to BPXWDYN is working, the OPEN will work even without a MYFILE DD statement.

Pankaj Gupta · New User Joined: 07 May 2008 Posts: 32 Location: Bangalore

Yes, that is being a good point re abendaid not knowing about the dynamic allocation.

The documentaiton for BPXWDYN is so poor that I am not sure where is being the return code or I would have checked. Would it perhaps be in R15?

Robert Sample · Posted: Tue Oct 14, 2008 8:15 pm Post subject:

If you look in this ftp://ftp.software.ibm.com/s390/zos/tools/bpxwdyn/bpxwdyn.html you can find

Pankaj Gupta · New User Joined: 07 May 2008 Posts: 32 Location: Bangalore

Oh well. R15 is seeming to have 0000FD9A after the call.

I might as well be giving up as there seems not much else I can be doing.

enrico-sorichetti

if I remember correctly the format of the parameter list to be passed on a link macro id the same You would get at program initiation
something like

dick scherrer · Posted: Tue Oct 14, 2008 11:41 pm Post subject:

Hello,