[#300620] plustek: driver hangs when pthreads are used.

Date:
2004-04-06 13:05 Priority:
3

State:
Closed

Submitted by:
Mattias Ellert (ellert-guest) Assigned to:
Gerhard Jaeger (gja-guest)

Category:
backends (drivers) Group:

Resolution:
Accepted

Summary:
plustek: driver hangs when pthreads are used.

Detailed description
The plustek driver hangs on platforms using pthreads (like e.g. MacOS X). The reason for this has been identified as the following: When the reader process is started with fork (like on linux), the file descriptors in the reader process are automatically closed when the reader process ends. The read call in the main process then exits because the write end of the pipe was closed when the reader process exited. However, when pthreads are used (like on MacOS X) the file descriptors are not closed when the reader thread ends, since in this case the file descriptors are shared between the threads. The read call therefore never exits, since both ends of the pipe are still valid file descriptors. (Note that this problem is not introduced by the workaround for the broken pthread_cancel call on MacOS X, but present on all platforms that uses threads.) The attached patch has been tested and reportedly solves the problem. For more information see the following thread on sane-devel: http://lists.alioth.debian.org/pipermail/sane-devel/2004-April/010687.html http://lists.alioth.debian.org/pipermail/sane-devel/2004-April/010698.html http://lists.alioth.debian.org/pipermail/sane-devel/2004-April/010699.html http://lists.alioth.debian.org/pipermail/sane-devel/2004-April/010701.html http://lists.alioth.debian.org/pipermail/sane-devel/2004-April/010702.html

Followup

Message
Date: 2004-04-09 12:26 Sender: Gerhard Jaeger Logged In: YES user_id=2913Thanks for the report. This bug is fixed in CVS now.

Attachments:

sane-plustek.patch

Field	Old Value	Date	By
status_id	Open	2004-04-09 12:26	gja-guest
Resolution	None	2004-04-09 12:26	gja-guest
close_date	2004-04-09 12:26	2004-04-09 12:26	gja-guest
assigned_to	none	2004-04-08 17:17	hmg-guest
File Added	65: sane-plustek.patch	2004-04-06 13:05	ellert-guest