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From: Adam Goode <adam@spicenitz.org>
To: linux-serial@vger.kernel.org
Subject: TIOCMIWAIT hopelessly broken?
Date: Fri, 13 Mar 2009 22:13:30 -0400	[thread overview]
Message-ID: <49BB12CA.9000604@spicenitz.org> (raw)

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Hi,

The ioctl TIOCMIWAIT seems to be inadequate for tracking changes in the
modem status lines. The main problem is that it cannot be used without
racing: if the status change you are waiting for happens before your
ioctl, you will wait forever.

A solution would be one like a eventfd, something that can be put to
poll(), epoll(), or select(), and where you read the status changes with
read().

Any ideas on how to do this? Would it be a new syscall, something in
/sys, a flag to open() ?


Thanks,

Adam


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                 reply	other threads:[~2009-03-14  2:13 UTC|newest]

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