qfork()

[marc at arnor.uucp]

Submitted-by: marc at arnor.uucp

It would be useful to know why the function is being proposed.  One
assumes an efficiency improvement, which implies that the specifiers
have an implementation in mind.

Also, it should be remembered that unix systems don't execute C - they
execute machine instructions generated by the C compiler.  So it is
necessary to specify the behavior in machine terms if the compiler
writers are going to comply.  In particular, there is nothing to
prevent the compiler from moving certain computations to the space
between the qfork and the exec!  Does a compiler need to recognize
qfork and exec as special?

Finally - if the intent is to "bundle" fork and exec together,
assuming only that the fork succeeds, would it not be better to
propose fexec* - a set of exec calls which fork first?  Of course,
this makes it absolutely clear that nothing can happen between fork
and exec.  If the combined function is then deemed useless, how can
the qfork/exec idiom be better?
--

Marc Auslander       <marc at ibm.com>


Volume-Number: Volume 22, Number 44