Date: Wed, 9 Feb 2005 10:51:36 -0500 From: Brian Fundakowski Feldman <green@freebsd.org> To: Dmitry Agaphonov <rzhe@agava.com> Cc: freebsd-hackers@freebsd.org Subject: Re: kqueue & pthread Message-ID: <20050209155136.GC65523@green.homeunix.org> In-Reply-To: <20050209183952.30f4c5b6.rzhe@agava.com> References: <20050209173625.29d50ffd.rzhe@agava.com> <20050209144924.GB65523@green.homeunix.org> <20050209183952.30f4c5b6.rzhe@agava.com>
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On Wed, Feb 09, 2005 at 06:39:52PM +0300, Dmitry Agaphonov wrote: > On Wed, 9 Feb 2005 09:49:24 -0500 > Brian Fundakowski Feldman <green@freebsd.org> wrote: > > BFF> Since you're using user threads, not kernel threads, the kernel can only > BFF> have one "object" (poll or select list, or kqueue file descriptor) to wait > BFF> upon at any given time. Since kqueues are pollable, what happens is > BFF> that the kqueue along with every other fd being polled/selected are all > BFF> polled by a single poll(2) system call. Yes, your kqueue is being used, > BFF> but it has an indirection of another poll(2) system call determining > BFF> when your kevent(2) thread should be woken up. > > Brian, thank a lot for your explanation! > > So, pthreads since they are user threads do not provide concurrency on > multiprocessor systems? Right, the libc_r implementation specifically. > And by the way, are there another ways to have kernel threads in FreeBSD 4.x > applications, rather than use LinuxThreads port or implement it via rfork'ed > processes? The LinuxThreads library seems to be the best-supported way. I don't think that there should be legal/licensing issues using it. -- Brian Fundakowski Feldman \'[ FreeBSD ]''''''''''\ <> green@FreeBSD.org \ The Power to Serve! \ Opinions expressed are my own. \,,,,,,,,,,,,,,,,,,,,,,\
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