[lldb-dev] Moving test runner timeout logic into Python

[Zachary Turner via lldb-dev]

No obvious reason I see why that wouldn't work.  You probably want to wrap
the "thread 1" code in a try: ... except: pass because p.terminate probably
will cause an exception on the other thread.

On Wed, Sep 23, 2015 at 2:40 PM Todd Fiala <todd.fiala at gmail.com> wrote:

> A nice bit here, also, is for those places where we are using timeout
> (Linux, OS X, etc.) we get to trade off and use a thread where we were
> using a whole different process.  (i.e. the timeout wrapper process goes
> away).
>
> On Wed, Sep 23, 2015 at 2:38 PM, Todd Fiala <todd.fiala at gmail.com> wrote:
>
>> Yep - the approach (for now) is likely to look like:
>>
>> p = subprocess.Popen(...) # exact call differs between Windows/Non-Windows
>>
>> done_event = # some kind of semaphore/event, probably
>> threading.Thread.Event()
>>
>> spinup thread 1, running this code:
>>     # Thread 1 - grab output, do communicate() call
>>     p.communicate()
>>     # Signal we finished - the process ended successfully.
>>     done_event.signal()
>>
>> # ...back to the thread that called subprocess.Popen()
>>
>> # Wait for time timeout value for the inferior dotest.py process to
>> complete..
>> timed_out = done_event.wait(timeout_in_seconds)
>>
>> # If timed_out indicates the timeout occurred, we timed out.
>> # And thus, the process did not finish on time.
>> if timed_out == True:
>>    # Kill the inferior dotest
>>    p.kill() # or p.terminate()
>>    # This will cause the other thread to fall through now, but we know it
>> timed out.
>>    # Could get fancier here and do a nice kill, then a less blockable
>> kill.  But make the
>>    # process die one way or another.
>>
>> # do the other post-process activity here...
>>
>>
>>
>> ^= that's rough pseudo-code.  I need to look up a few details.  But
>> that's more or less what I was thinking.  Looked like all of that was
>> available on Windows.  We can also have it only optionally time out.
>>
>> Something like that is what I had in mind.
>>
>> On Wed, Sep 23, 2015 at 2:28 PM, Zachary Turner <zturner at google.com>
>> wrote:
>>
>>> Can you offer a hint about how you plan to implement this?  When you say
>>> it we should get the same behavior everywhere, I assume this means Windows
>>> too, which currently does not support running with a timeout at all
>>> (because timeout / gtimeout aren't present)
>>>
>>> On Wed, Sep 23, 2015 at 2:22 PM Todd Fiala via lldb-dev <
>>> lldb-dev at lists.llvm.org> wrote:
>>>
>>>> Hi all,
>>>>
>>>> Over the last two days, I've hit some inconsistencies across platforms
>>>> surrounding signal handling and the operation of the timeout/gtimeout
>>>> executable mechanism that we use to handle timeouts of tests.  The net
>>>> result is I still see tests sometimes hang up the test running process,
>>>> even though my changes in the last couple days seem to have reduced the
>>>> frequency somewhat.
>>>>
>>>> I'd like to address that once and for all with something that is less
>>>> likely to differ across platforms.  I have a relatively simple way to do
>>>> that within the parallel test runner directly.  I'm planning on prototyping
>>>> that now, but before I dive too far into that, I wanted to expose the idea
>>>> in case somebody had any major concerns with not using timeout/gtimeout on
>>>> the systems that had it.
>>>>
>>>> I expect it to be a relatively small change when I get it up for review.
>>>>
>>>> The nice thing about going straight-python on it is we should get the
>>>> same behavior everywhere, and not depend on signal handling to do it.
>>>>
>>>> Thoughts?
>>>> --
>>>> -Todd
>>>> _______________________________________________
>>>> lldb-dev mailing list
>>>> lldb-dev at lists.llvm.org
>>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-dev
>>>>
>>>
>>
>>
>> --
>> -Todd
>>
>
>
>
> --
> -Todd
>
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