From: Will Lentz <will_lentz@trimble.com>
To: Andrew Lunn <andrew@lunn.ch>
Cc: Hans H?bner <hans@huebner.org>, ecos <ecos-discuss@ecos.sourceware.org>
Subject: Re: [ECOS] uipc_socket.c (and cyg_tcp_maxidle)
Date: Fri, 17 Jun 2005 21:00:00 -0000 [thread overview]
Message-ID: <1119041995.32361.0.camel@localhost.localdomain> (raw)
In-Reply-To: <20050617200916.GB17597@lunn.ch>
Thanks! That works great :-)
On Fri, 2005-06-17 at 22:09 +0200, Andrew Lunn wrote:
> On Thu, Jun 16, 2005 at 09:01:23AM +0200, Hans H?bner wrote:
> > On Wed, 15 Jun 2005, Will Lentz wrote:
> >
> > >I may have found a potential bug in
> > >packages/net/bsd_tcpip/current/src/sys/kern/uipc_socket.c (or I may be
> > >completely wrong :-).
> > >
> > >At the end of sodealloc(), the following code exists:
> > > zfreei(so->so_zone, so);
> > > wakeup(so->so_zone);
> > >The problem is that zfreei() changes so->so_zone. Shouldn't wakeup() be
> > >done on the original so->so_zone? I only noticed this problem by:
> > >1- while(1) {
> > > sock = socket( AF_INET, SOCK_STREAM, IPPROTO_TCP );
> > > connect( sock, ... );
> > > close( sock );
> > > }
> > > Eventually this pauses in socket() (in cyg_tsleep()) when you run out
> > >of eCos sockets.
> > >
> > >2- After 2*MSL or so, cyg_wakeup() gets called with chan == 0x0. Why?
> > >The zfreei() call in sodealloc() changes so->so_zone to 0 before the
> > >wakeup() call.
>
> This is not quite correct. zfreei() does not change so->so_zone. What
> it does is return the memory for the so structure to the pool. The
> wakeup then uses the memory which has just been returned to the
> pool. There is a race condition. Once back into the pool the memory
> could be allocated to another thread before the call to wakeup is
> made.
>
> Attached is a patch to fix this.
>
> Andrew
--
Before posting, please read the FAQ: http://ecos.sourceware.org/fom/ecos
and search the list archive: http://ecos.sourceware.org/ml/ecos-discuss
prev parent reply other threads:[~2005-06-17 21:00 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-06-15 22:39 [ECOS] uipc_socket.c Will Lentz
2005-06-16 7:06 ` [ECOS] uipc_socket.c (and cyg_tcp_maxidle) Hans Hübner
2005-06-16 15:36 ` Will Lentz
2005-06-16 15:51 ` Hans Hübner
2005-06-16 16:06 ` Will Lentz
[not found] ` <20050616183534.N69813@web.m68k.de>
2005-06-16 23:45 ` Will Lentz
2005-06-17 7:15 ` Andrew Lunn
2005-06-17 20:12 ` Andrew Lunn
2005-06-17 21:00 ` Will Lentz [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1119041995.32361.0.camel@localhost.localdomain \
--to=will_lentz@trimble.com \
--cc=andrew@lunn.ch \
--cc=ecos-discuss@ecos.sourceware.org \
--cc=hans@huebner.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).