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

[Bob Koehler]

In article <7llbk1F3eetdpU1 at mid.individual.net>, billg999 at cs.uofs.edu (Bill Gunshannon) writes:
> 
> Then, what exactly is the reason VMS can't do a Unix style fork()?

   As I mentioned before, VMS Engineering has said it would be trvial
   to alter the kernel so as to fork a process with the same memory
   map as an existing process.  What would not be trivial would be
   modifying the I/O subsystem.

   The VMS I/O subsystem assumes exclusive file opens by default, and
   implements the concept of "noshare" devices.  Getting around
   "noshare" is already there for subprocesses under some circumstances, 
   but not in general.  Changing either exclusive open or generalizing 
   around "noshare" would break lots of working code.

   So how do you both enforce the existing I/O rules and break them?  To
   date VMS Engineering has not taken on that dilema.