Re: [PATCH] immortal helpers

2010/2/23 Henrik Nordström <henrik_at_henriknordstrom.net>:
> mån 2010-02-22 klockan 10:20 +0100 skrev Kinkie:
>
>> Unfortunately it's implementation-dependent. For all we know
>> posix_spawn may be a library convenience wrapper around fork/exec..
>> (vfork if we're lucky).
>
> Well, it's been around for quite some time now.
>
> If we want to argue about oldish systems then UNIX domain fd passing is
> also known to be broken on many older OS:es in various manners.
>
> The question is, is there any system we want to support which lacks
> posix_spawn or a similar alternative?

This bug http://sources.redhat.com/bugzilla/show_bug.cgi?id=10354
shows that in glibc many cases posix_spawn() is exactly a wrapper for
(v)fork/exec .
So it is no worse than fork/exec, may be as good as vfork/exec
depending on the conditions, but not any better than it. Definitely
not as good as Windows' CreateProcess (in theory - Windows'
performance when creating new processes is horrible, but the API
design is in this regard sane)

I'm not arguing against using it, just trying to make us all aware of
its added value.

-- 
    /kinkie