On Thu, Sep 10, 2009 at 2:29 PM, Philip Guenther<guent...@gmail.com> wrote: > It happens at initialization time of libpthread and is undone at exit > and exec. B It applies to all fds. B There is no manpage, as it's not > (supposed to be) application visible.
OK, so basically this is an OpenBSD/pthread bug. I'm still sort of shell-shocked here. The idea is that *all* file descriptors are made non-blocking, and then the file-descriptor syscalls are wrapped to pretend they are blocking. As long as all of the code operating on those "pseudo-blocking" files is using the wrapped syscalls, all is well. However, when one of those files is accessed by a binary not linked to libpthread, the illusion breaks down. Do I have that right? Why does the fcntl(fd, F_GETFL) fix it? Does it really fix it, or are we just lucky? This sounds like more of a design bug than a code bug, so I don't expect a fix in a 4.5 patch release. So we'll need to do something to work around it in Amanda. Presumably this is a fairly common problem, so what is the usual solution? Dustin -- Open Source Storage Engineer http://www.zmanda.com
