Re: [Caml-list] Threads & Fork

[Matthew Hannigan <mlh@zip.com.au>]

On Tue, Nov 22, 2005 at 04:50:02PM +0100, Oliver Bandel wrote:
> On Tue, Nov 22, 2005 at 04:39:07PM +0100, Florian Weimer wrote:
> > * Jonathan Bryant:
> > 
> > > I'm confused as to why the attached code hangs.  My understanding of
> > > Unix.fork () is that it completely clones the current process, which in
> > > my understanding, clones the processes's threads as well.  Apparently,
> > > though, that is not the case, because I can't join the thread in both
> > > the parent and the child.
> > 
> > I can't speak for the OCaml run-time, but POSIX fork only duplicates
> > the current thread, so the new process is essentially single-threaded.
> 
> I doubt that this is true.
> Unix-fork() copies a complete process.
> If the original has threads, the copy also have.
> I don't think that POSIX handles this different to old Unix API.

from the solaris10 man page for fork; note the last sentence.


     A call to fork1()  replicates  only  the
     calling thread in the child process.

     In Solaris 10, a call to fork() is identical to  a  call  to
     fork1();  only the calling thread is replicated in the child
     process. This is the POSIX-specified behavior for fork().


--
Matt