Path: utzoo!mnetor!uunet!lll-winken!lll-tis!ames!pasteur!ucbvax!CITHEX.CALTECH.EDU!carl
From: carl@CITHEX.CALTECH.EDU (Carl J Lydick)
Newsgroups: comp.os.vms
Subject: Re: Process Communication.
Message-ID: <880314030659.746@CitHex.Caltech.Edu>
Date: 14 Mar 88 11:11:47 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 17


 > I am faced with the following problem and I would appreciate anyone
 > sending me a note of hope saying that I really do not have a problem.
 > Well, here it is :
 > 
 >  While in the main process, I SPAWN/NOWAIT a process that does something
 > completely different from what I am doing in the main process. The problem
 > arizes when the SPAWNed subprocess wants an interactive input (and it must
 > be interactive). Can the subprocess `hang' the main process until it receives
 > what it wants ? If not, what would you suggest ?

Sort of.  QIO[W]s to a given terminal device are processed on a first  queued,
first  served basis.  This means that if both the main process and the spawned
process want to read from your terminal, and the spawned  process  queues  its
I/O  request  first, the main process won't do anything until you've satisfied
the subprocess's request, then that of the  main  process.   If  this  doesn't
answer  your  question,  please  repost it, being more specific regarding your
problem.