On Sat, Feb 25, 2012 at 10:21 AM, Nala Ginrut <nalagin...@gmail.com> wrote:
> > > On Sat, Feb 25, 2012 at 2:57 AM, Andy Wingo <wi...@pobox.com> wrote: > >> Hello :) >> >> On Fri 24 Feb 2012 04:00, Nala Ginrut <nalagin...@gmail.com> writes: >> >> > I think I could use pipes to handle some sub-process rather than do it >> > with fork manually. But I must create a daemon, it can't avoid to use >> > fork, will this circumstance cause problems if I use threads after it? >> >> Hummm. Very good question. I started to answer this, but ended up >> committing the hack I mailed before, then found this reply now. >> >> Basically, if you try to daemonize with fork, you would need to do it >> very early, before your program makes any threads. In master, Guile now >> enforces that condition. >> >> > So, this suggestion implies primitive-fork would be kept? > > >> Note that the first time your program calls `sigaction', Guile spawns a >> thread to handle signals. You'd need to fork before installing signal >> handlers. >> >> > Fortunately. ;-) > > >> Another thing to think about is libgc. In the "master" branch, libgc >> itself can spawn threads -- for example, a thread for doing parallel >> marking. >> >> There is a tension here between making things work, and making them >> correct. It is possible to get fork + threads mostly working on glibc >> platforms -- for example, we could restart signal-handling and finalizer >> threads in primitive-fork. But it is not possible to make the use of >> `primitive-fork' correct, in general, in the presence of threads. >> >> > I think all I need primitive-fork is just to daemonize, and I can try to > do it in the very early. > Moreover, primitive-fork would be restricted to be used for daemon to > anybody. > Considering this point, why not add a "daemonize" proc instead of > "primitive-fork"? > Well, I missed something. 'primitive-fork' shouldn't be removed directly according to previous discussion, unless the user chosen ptheads. If they do not use threads, then primitive-fork would be useful, is that right? > Cheers, >> >> Andy >> -- >> http://wingolog.org/ >> > >
