serial and threads

Silke natunika at gmx.de
Wed Aug 18 09:35:17 CEST 2004


Hi Peter,

I only verified this by checking it out. Here is the code

import sys
sys.path.append('c:\\python23\\lib\\site-packages\\serial')
import thread           #This module provides low-level primitives for
working with multiple threads
import threading        #This module constructs higher-level threading
interfaces on top of the lower level thread module.
import serialwin32      #Python Serial Port Extension for Win32,
Linux, BSD, Jython; serial driver for win32; see __init__.py
import socket           #Low-level networking interface
import binascii         #Convert between binary and ASCII

def NetworkToSerial(input):
        s.write(binascii.unhexlify(input))        
        print "SENT: %s" % input                  # %s: if command is
not string format to string

def SerialToNetwork():
        result = s.read(12)
        print "RECEIVED:"
        print binascii.hexlify(result)          
             
s = serialwin32.Serial ()
s.port = 0                      #COM1
s.baudrate = 115200
s.databits = 8
s.timeout = None                   #None=wait forever; 0=return
immediately on read; x = x seconds
s.open()

command = "0b02ff0512340000000255aa"

sthread = threading.Thread(target=NetworkToSerial(command))
rthread = threading.Thread(target=SerialToNetwork)

sthread.start()
rthread.start()
sthread.join(5)
rthread.join(5)

s.close()

and it does exactly what I want it to do, so I guess it's ok...

Thank you for your help!

Bye

Silke


Peter Hansen <peter at engcorp.com> wrote in message news:<U9udnZz_B_2ms7_cRVn-hQ at powergate.ca>...
> Silke wrote:
> > I already found a solution using 'threading' instead of 'thread' :-)
> 
> Are you positive that is really a solution?  If the original
> problem was truly because of a thread-safety issue, then it's
> most likely, I think, that it was a race condition and that
> it could very well re-appear in the future.
> 
> The "threading" module is mostly just a higher level API on
> top of the "thread" module, so that change alone seems unlikely
> to solve the issue, unless there is code in serialwin32 specifically
> to do the proper locking when the threading module is used...
> 
> -Peter



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