OSError: [Errno 12] Cannot allocate memory

[duncan smith]

On 30/11/16 17:57, Chris Angelico wrote:
> On Thu, Dec 1, 2016 at 4:34 AM, duncan smith <duncan at invalid.invalid> wrote:
>>
>> def _execute(command):
>>     # shell=True security hazard?
>>     p = subprocess.Popen(command, shell=True, stdin=subprocess.PIPE,
>>                          stdout=subprocess.PIPE,
>>                          stderr=subprocess.STDOUT,
>>                          close_fds=True)
>>     output = p.stdout.read()
>>     p.stdin.close()
>>     p.stdout.close()
>>     #p.communicate()
>>     if output:
>>         print output
> 
> Do you ever wait() these processes? If not, you might be leaving a
> whole lot of zombies behind, which will eventually exhaust your
> process table.
> 
> ChrisA
> 

No. I've just called this several thousand times (via calls from a
higher level function) and had no apparent problem. Top reports no
zombie tasks, and memory consumption and the number of sleeping tasks
seem to be reasonably stable. I'll try running the code that generated
the error to see if I can coerce it into failing again. OK, no error
this time. Great, an intermittent bug that's hard to reproduce ;-). At
the end of the day I just want to invoke dot to produce an image file
(perhaps many times). Is there perhaps a simpler and more reliable way
to do this? Or do I just add the p.wait()? (The commented out
p.communicate() is there from a previous, failed attempt to fix this -
as, I think, are the shell=True and close_fds=True.) Cheers.

Duncan