On Sep 10,  1:38pm, nathanw@wasabisystems.com ("Nathan J. Williams") wrote:
-- Subject: Re: popen reentrant (was Re: SA/pthread and vfork)

| > It seems to me that the vfork semantics should be changed so that upcalls
| > should not be happening while the child is running on the parent's stack.
| > Maybe we should introduce a process flag that indicates P_INVFORK, and
| > have execve clear it. While a process is in P_INVFORK, it cannot execute
| > upcalls.
| 
| Again, I think this is the wrong approach. Instead of making vfork()
| work with SAs, we should consider avoiding vfork() in threaded
| programs and taking the hit of calling ordinary fork() instead.

Absolutely not. We should either not allow vfork() on threaded programs
having it return SIGSYS, or make it work properly. Relying on threaded
programs `knowing' that they should not call vfork() is a recipe for
disaster. Finally, having vfork() work is easy enough...

christos