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

[Bill Gunshannon]

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.

bill
 

-- 
Bill Gunshannon          |  de-moc-ra-cy (di mok' ra see) n.  Three wolves
billg999 at cs.scranton.edu |  and a sheep voting on what's for dinner.
University of Scranton   |
Scranton, Pennsylvania   |         #include <std.disclaimer.h>