On Wed, Sep 21, 2011 at 8:09 PM, Atherun <athe...@gmail.com> wrote: > This is on windows with python 2.6. > I can't seem to remove a possibility of a deadlock in one of my > scripts at the moment. Its not a constant deadlock but it appears > from time to time. The code is below: > > try: > > process = > subprocess.Popen(cmd,stdout=subprocess.PIPE,stderr=subprocess.STDOUT) > > NotDone = True > data = [] > while NotDone: > NotDone = False > > result = process.poll() > if result == None: > NotDone = True > if NotDone: > out, err = process.communicate() > Log(out) > > I was able to get the program to write out the stack trace for my > threads and it is usually deadlocked on sys.stdout.read or > _internal_poll of subproceess. > > I've even tried the above, with using "with > tempfile.NamedTemporaryFiles() as buff:" and writing to the file, but > it still deadlocks. In the past I work around this by running fewer > processes asynchronously but I would really like to get this solved so > I don't have to wait to see if it'll be caused with any changes I > make. > > Any tips would be appreciated.
Your polling loop is completely pointless. The code can be simplified to: process = subprocess.Popen(cmd,stdout=subprocess.PIPE,stderr=subprocess.STDOUT) out, err = process.communicate() log(out) Depending on the particular program you're running in a subprocess, you may need to take heed of the Note in the communicate() docs: "Note: The data read is buffered in memory, so *do not use this method* if the data size is large or unlimited." [Emphasis added] Cheers, Chris -- http://rebertia.com -- http://mail.python.org/mailman/listinfo/python-list
