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Re: [PATCH] Work around performance bug in subprocess.Popen.communicate()

From
KWKarl Wiberg <kha@virtutech.com>
Date
Aug 4, 2009, 08:51 UTC
Message-ID
<20090804085125.GB27452@lux.e.vtech>
In-Reply-To
<b0943d9e0907310427r7e59aa5fi5e5ff5e3f3c03819@mail.gmail.com>
On 2009-07-31 12:27:53 +0100, Catalin Marinas wrote:
> But can this not lead to a deadlock if the __indata is big? The
> stdout of the created process is only processed once the whole
> __indata is written. I thought communicate() was created to avoid
> this issue.

I don't think there's a problem. write() isn't supposed to have a limit on the amount of data it will accept in one call, as far as I'm aware. Plus, it works just fine with Erik's test case---which in my case was about 7 MB. If it can handle 7 MB, I doubt there's a limit we'll hit anytime soon.

Oh, and we still call communicate()---we just don't pass it any additional bytes to write to stdin.

-- 
Karl Wiberg, Virtutech
Previous: Catalin MarinasNext: Catalin Marinas
Message 3 of 7 in “Work around performance bug in subprocess.Popen.communicate()”
  1. Work around performance bug in subprocess.Popen.communicate()Karl Wiberg, Jul 31, 2009
  2. Catalin MarinasJul 31, 2009
  3. Karl WibergAug 4, 2009
  4. Catalin MarinasAug 13, 2009
  5. Karl WibergAug 14, 2009
  6. Erik SandbergAug 14, 2009
  7. Karl WibergAug 14, 2009

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