Simple threading example freezes IDLE?

Sergio Correia sergio.correia at gmail.com
Wed Sep 26 19:01:42 EDT 2007


I think I have pinpointed the error:

When the -print- command fills the screen, IDLE crashes. That is, if i
have 30 empty lines before I start to push the current screen upwards,
when the last of those lines is used, and its time to push the screen
upwards, IDLE crashes.

I'm using IDLE 1.2.1, Python 2.5.1, and Tk 8.4. Does anyone has any
idea of why is this happening?

Thanks,
Sergio

Example code   --->  http://pastebin.com/f21868e26

import time
import Queue
import threading

class Worker(threading.Thread):

    def __init__(self,  inQueue, **kwds):
        threading.Thread.__init__(self, **kwds)
        self.inQueue = inQueue
        self.setDaemon(True)
        self.start()

    def run(self):
        while True:
            item = self.inQueue.get()
            print item
            self.inQueue.task_done()
            time.sleep(0.1)

qSymbols = Queue.Queue()
symbols = range(50)
for symbol in sorted(symbols):
    qSymbols.put_nowait(symbol)

Worker(qSymbols) # Start thread
qSymbols.join()
print "The End..."




On 9/26/07, Sergio Correia <sergio.correia at gmail.com> wrote:
> I think the -print- command, as used in IDLE, is not thread-safe. I
> was bitten by an issue like that today, and the problem ended up being
> the -print- command I used.
>
> On the cmd line, it works per-fect-ly.. but IDLE seems to be the culprit.
> A possible answer seems to be to write a wrapper for print that makes
> it thread safe (with the help of a lock.
>
> On 9/19/07, writser at gmail.com <writser at gmail.com> wrote:
> > hey all,
> >
> > For my study I'm writing a simple threaded webcrawler and I am trying
> > to do this in python. But somehow, using threads causes IDLE to crash
> > on Windows XP (with the latest python distribution 2.5.1). Even a
> > simple example such as this:
> >
> > import thread, time
> >
> > def doSomething():
> >   print "something"
> >
> > for i in range(2):
> >   thread.start_new(doSomething, ())
> >
> > causes IDLE to freeze when I type it in the interpreter. Using the
> > python command line everything works just fine. Using IDLE on Debian
> > linux also does not cause anything to crash. What am I overlooking?
> >
> > regards, Writser Cleveringa
> >
> > --
> > http://mail.python.org/mailman/listinfo/python-list
> >
>



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