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Race conditions in serial_select

From: "Gaer, A." <Andreas dot Gaer at baslerweb dot com>
To: ecos-patches at ecos dot sourceware dot org
Date: Fri, 17 Jun 2005 11:47:09 +0200
Subject: Race conditions in serial_select

Hello all!

The serial_select() implementation from
"io/serial/current/src/common/serial.c" doesn't care about concurrent access
to the cbuf structure. This leads to race conditions when the serial DSR
routine changes the counters in this structure while select checks for
"cbuf->nb == 0". As a result, user threads that sleep because of a select
call will not be woken up, even if data arrives. Also access to this
structure isn't implemented thread-safe because of missing mutex locks. The
attached patch fixes this problems.

Best regards,
 Andreas.
_______________________________

Andreas Gäer
Software Engineer

Basler Vision Technologies
An der Strusbek 60-62 
22926 Ahrensburg 
Germany 

Tel +49 (4102) 463-517
Fax +49 (4102) 463-46211 

mailto: Andreas.Gaer@baslerweb.com
http://www.baslerweb.com
_______________________________

Attachment: serial_select.diff
Description: Binary data

Follow-Ups:
- Re: Race conditions in serial_select
  - From: Andrew Lunn

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