How to intepret c++ process ubuntu

Question

I'm running some C++ code (8 independent processes running on Ubuntu with 8 cores).

I'm launching the C processes using python:

def runC():
    numThreads = multiprocessing.cpu_count()
    threads = []
    for i in range(numThreads):
        args = ("./cprogram", arg1,arg2,arg3)
        popen = subprocess.Popen(args, stdout=subprocess.PIPE,stderr=subprocess.PIPE)
        threads.append(popen)

    for t in threads:
       t.wait()
       output = t.stdout.read()
       err = t.stderr.read()
       if len(output) > 0:
          print "output: " + output
       if len(err) > 0:
          print "err: " + err

I keep getting "defunct" processes. What does that mean? Why did this happen to me?

This is far too vague to even know what you're talking about, let alone answer any questions. Can you please give a more detailed description. — Paul Evans, Sep 13 '13 at 12:53

score 0 · Accepted Answer · answered Sep 13 '13 at 13:35

0

Turns out it's the t.wait() that is causing the zombie process. Depending on the order that the jobs finish, there will be some in a zombie state until the t.wait() gets around to them. It's not really a problem, which is what I wanted to be sure of.

answered Sep 13 '13 at 13:35

Tom Swifty

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How to intepret c++ process ubuntu

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