[Info-vax] Looking into C-include files on VMS

[VAXman- at SendSpamHere.ORG]

In article <7llbk1F3eetdpU1 at mid.individual.net>, billg999 at cs.uofs.edu (Bill Gunshannon) writes:
>In article <V1oGFRPkr7y3 at eisner.encompasserve.org>,
>	koehler at eisner.nospam.encompasserve.org (Bob Koehler) writes:
>> In article <7lh139F3dd464U1 at mid.individual.net>, billg999 at cs.uofs.edu (Bill Gunshannon) writes:
>>> In article <baOjfZKhGtEy at eisner.encompasserve.org>,
>>> 	koehler at eisner.nospam.encompasserve.org (Bob Koehler) writes:
>>>> In article <7ld3naF3d1kahU4 at mid.individual.net>, billg999 at cs.uofs.edu (Bill Gunshannon) writes:
>>>>> In article <hcrfk0$bth$3 at naig.caltech.edu>,
>>>>> 	glen herrmannsfeldt <gah at ugcs.caltech.edu> writes:
>>>>>> 
>>>>>> I presume VMS has some way to share data when needed, though.
>>>>>  
>>>>> None that I have ever seen.
>>>>> 
>>>> 
>>>>    You haven't seen mmap()?  Or $CRMPSC?  Or an installed, writable
>>>>    section?
>>> 
>>> The discussion was about fork(), not mmap().  
>> 
>>    The statement "VMS has some way to share data" is more generic than
>>    fork().
>> 
>>>The sharing done between
>>> forked processes is, as far as I know, not possible under VMS.  That
>>> is, there is no way for two processes to both have the ability to
>>> read/write the exact same variables and devices.
>> 
>>    I've shared variables across processes for a great many years on
>>    VMS.  I've also shared devices, even devices marked noshare, without
>>    any kernel hacks or interprocess hand off.
>> 
>>>  Unix fork() does
>>> this precisely.  For an easy to understand example, just take a look
>>> at the source to the connect portion of  UXKermit.  The program opens
>>> a serial device, forks and then one process handles input from the
>>> serial port while another process handles output thru that same serial
>>> port.  Can two totally separate processes under VMS both access a single
>>> serial port simultaneously?
>> 
>>    Been there, done that.
>
>Then, what exactly is the reason VMS can't do a Unix style fork()?
>
>This more than anything else I know of is what keeps the majority of
>Open Source Unix applications from being able to be ported.

I'd ask, what exactly DOES VMS need to do to implement a unix style fork?
The barest essential, please.  I love to hack! ;)  

-- 
VAXman- A Bored Certified VMS Kernel Mode Hacker    VAXman(at)TMESIS(dot)ORG

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