In article <098f3d78-85f5-44e7-ba72-f2270a24d...@o9g2000vbo.googlegroups.com>, 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. My reading of the docs (http://docs.python.org/release/2.6.7/library/subprocess.html#popen-objec ts) says that Popen.poll() doesn't return a value, it sets the object's return code attribute, which you can then interrogate. More than that, your loop logic looks amazingly complicated for what's basically a simple thing. I suggest something along the lines of: # assuming process.returncode is initially None while process.returncode is None: out, err = process.communicate() Log(out) I haven't tested that, but I think (from reading the docs) that's the right idea. -- http://mail.python.org/mailman/listinfo/python-list
