Re: A guile story

[Kevin Ryde]

Neil Jerram <address@hidden> writes:
>
> I eventually narrowed this down to the interaction between calling
> accept on the main FTP server thread at the same time as read on the
> FTP data connection thread (which is where the breakpoint was hit).
> At least, the problem was apparently fixed by inserting a select
> before the accept, so that the accept never blocked.  I'm aware that
> this problem has been reported before, and that someone prepared a
> patch to fix it, but (i) I thought we had applied that patch, and (ii)
> I thought the problem affected coop threads only, not pthreads.

I ran into recvfrom() blocking all threads not so long ago too.  I
forget if I posted here about it, but I put a remark in the manual,

     On a GNU/Linux system `recvfrom!' is not multi-threading, all
     threads stop while a `recvfrom!' call is in progress.  An
     application may need to use `select', `O_NONBLOCK' or
     `MSG_DONTWAIT' to avoid this.

It's tempting to try to do better in guile, though no doubt it'd help
everybody if it could be improved in libc or libpthreads or wherever.