[Info-vax] select() returning -1

[BillPedersen]

On Saturday, February 16, 2013 7:03:42 PM UTC-5, Sam Ferencik wrote:
> Hi,
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> 
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> Is there something wrong with the select() call on VMS? If so, is there a workaround, or an equivalent native DEC call?
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> ==Why I'm asking==
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> 
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> I'm looking at a problem in vim (on VMS only): vim freezes when you encounter the "swap file already exists" dialog and you hit <Esc>. Steps to reproduce here: http://www.polarhome.com/horde/whups/ticket/?id=15
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> 
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> I have drilled down (in the vim source code) to a select() call which always returns -1, meaning error. [http://linux.die.net/man/2/select]
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> ==Why I suspect select() on VMS==
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> There are two reasons I suspect this may be a VMS-specific problem of select():
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> 1) There's a comment in the vim source code (os_unix.c) saying
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>         /* Old VMS as v6.2 and older have broken select(). It waits more than
> 
>          * required. Should not be used */
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> Now, this is not my case: I'm using VMS 7.3, and select() definitely doesn't wait longer than required - it returns immediately with -1. But the comment is sufficient to raise my suspicion.
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> 
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> 2) http://saf.bio.caltech.edu/unix_to_vms_notes.txt says that "OpenVMS select() only works on sockets, it does NOT work on files." That would perhaps explain the behaviour I'm observing - but who knows but that the website is referring to VMS <= 6.2, same as the comment?
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> I will be grateful for any pointer.
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> Thanks,
> 
> Sam

You might look here:

     https://sourceforge.net/p/vms-ports/tickets/19/

We are in discussions with HP OpenVMS Engineering as to extending select() and poll() as we work with them on *nix Portability improvements.

The above references some existing workarounds.

If you have interest in getting involved please get back to me.

Thanks,

Bill.