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Reading asynchronous data from a serial device

julesk24 at my-deja.com julesk24 at my-deja.com
Mon Jul 17 08:50:01 EDT 2000 
I am attempting to write a program (to run on a
linux box) in python  which communicates to a
device via a serial port.  The problem is that
the device is not reliable in responding when
expected.  Therefore, I have many reads timeout.
I am relatively new to the world of multiple
threads so I am probably making many mistakes.
My current approach is to use a separate thread
for the read and then to join() the thread back
into the main thread if the read is not sucessful
within the given amount of time.  The end result
is hundreds of hung processes and an eventual
segmentation fault (the program needs to be
designed to run for days).  My questions are:

1)  Is there any (easy) way for me to cause the
thread to exit (not just join the processes)
after a timeout on a read?

2)  Is there a better way of reading for data
(without starting my own thread for the read
process and then trying to exit out of the thread
after a period of time)?

I have read through the newsgroups, but I haven't
found anything which specifically answers my
questions.  Thanks to anyone who can answer my
questions!

Julie Kempton
jmk11 at duke.edu


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