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Mailbox patch
- From: "Christopher Cordahi" <christopher dot cordahi at gmail dot com>
- To: "Nick Garnett" <nickg at ecoscentric dot com>
- Cc: ecos-patches at ecos dot sourceware dot org
- Date: Wed, 13 Sep 2006 21:30:24 -0400
- Subject: Mailbox patch
- Domainkey-signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:mime-version:content-type:content-transfer-encoding:content-disposition; b=OF/NMYwhJcbl+CYDXtV+xgrkmmzCsXbNCxgNvIbkIFcEd6QcIJc/cWgRe9c1Pc9K6uQhsdf2/iDqR4ZvmR8vTVPnQBBcdZ7VEcRQv9DNv+Fvu3EoFg/faWgXdRmVPRlE/bGcQjog8M1Gye4+7jP2wYLQpVuFu6mGfCmBdNjjwko=
Sorry I'm not replying to original message because I just joined the patches
mailing list, previously I was only reading the discuss list.
Nick Garnett wrote:
This patch addresses some issues with the mailbox implementation
raised by the following two threads:
http://ecos.sourceware.org/ml/ecos-devel/2006-08/msg00004.html
http://ecos.sourceware.org/ml/ecos-discuss/2006-08/msg00170.html
The second raised some problems with the use of mailboxes in LWIP. It
is not clear what the issue there was, I cannot see any obvious
problems with the mailbox implementation.
From my understanding of David's problem described in
http://ecos.sourceware.org/ml/ecos-discuss/2006-08/msg00200.html
when the queue contains an item, the following line is executed
to return the next item from the queue
ritem = itemqueue[ (count--, base++) ];
but when the queue is empty the thread sleeps and there is no corresponding
line when the thread resumes execution, thus an invalid item is returned
However: switching from mboxt2 to mboxt does introduce a slight change
in semantics for mailboxes.
What is the change in semantics?
--
Chris