Date: Fri, 29 Jun 2001 15:44:03 +0000 (GMT) From: "E.B. Dreger" <eddy+public+spam@noc.everquick.net> To: Peter Pentchev <roam@orbitel.bg> Cc: Terry Lambert <tlambert2@mindspring.com>, Chris Costello <chris@calldei.com>, freebsd-smp@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG Subject: Re: libc_r locking... why? Message-ID: <Pine.LNX.4.20.0106291534530.9285-100000@www.everquick.net> In-Reply-To: <20010629183352.D535@ringworld.oblivion.bg>
next in thread | previous in thread | raw e-mail | index | archive | help
> Date: Fri, 29 Jun 2001 18:33:52 +0300
> From: Peter Pentchev <roam@orbitel.bg>
>
> > > The threads scheduler is in user space. It converts a
> > > blobking call into a non-blocking call plus a context
> > > switch. THus blocking _IS_ a problem.
> >
> > Bad wording on my part again; perhaps "a problem that I [think
> > that] I have handled" is better. I'm use nb calls if possible;
> > else I have a long-running worker thread.
>
> I hope you understand that when the worker thread blocks,
> it's the process that blocks, and none of the other threads
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Yes.
> it's the process that blocks, and none of the other threads
^^^^^^^^^^^^^^^^^^^^^^^^^
> can run until the end of the syscall.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Again, I am *not* using pthreads. Worker thread = totally separate
process, created via rfork(2). One process blocks, others continue
running.
To reiterate: I'm *not* using pthreads or libc_r. I wanted to check my
work, and began looking at libc_r code, under the faulty ass-umption that
it ran multiple processes.
Now that I know that threads are implemented in a single process, and that
blocking calls are thunked to non-blocking calls, the locking that I
originally questioned makes sense.
Eddy
---------------------------------------------------------------------------
Brotsman & Dreger, Inc.
EverQuick Internet Division
Phone: +1 (316) 794-8922 Wichita/(Inter)national
Phone: +1 (785) 865-5885 Lawrence
---------------------------------------------------------------------------
Date: Mon, 21 May 2001 11:23:58 +0000 (GMT)
From: A Trap <blacklist@brics.com>
To: blacklist@brics.com
Subject: Please ignore this portion of my mail signature.
These last few lines are a trap for address-harvesting spambots. Do NOT
send mail to <blacklist@brics.com>, or you are likely to be blocked.
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-smp" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?Pine.LNX.4.20.0106291534530.9285-100000>