RFR 9: 8168517 : java/lang/ProcessBuilder/Basic.java failed

[Roger Riggs]

Hi,

On 10/28/2016 3:14 PM, David Holmes wrote:
> On 29/10/2016 3:48 AM, Roger Riggs wrote:
>> Hi David,
>>
>> On 10/27/2016 9:00 PM, David Holmes wrote:
>>>>> But this is the second waitFor call after the process is destroyed.
>>>>> Sorry I don't really see the point.
>>>> The tests were added to determine if waitFor(timeout) was handling the
>>>> timeout parameter correctly.
>>>> The 2nd test here was to check the datapath when the process already
>>>> been destroyed.
>>>> The 'extra' waitFor() ensures the process is gone.
>>>> But you are correct, this exercises a path through the waitFor code 
>>>> that
>>>> does not even look
>>>> at the timeout value so I'll remove the entire 2nd case.
>>>>
>>>> Webrev updated in place.
>>>> http://cr.openjdk.java.net/~rriggs/webrev-basic-destroy-8168517/
>>>
>>> Okay, but now you don't need the p.waitFor() after the destroy() at 
>>> all.
>>>
>>> Hmmm ... I guess either we want the original code with a longer
>>> timeout to accommodate slow/loaded platforms (to test that waitFor(n)
>>> after a destroy() is timely); or everything after destroy() can be
>>> deleted.
>> Here's another approach to test whether waitFor(timeout) is behaving as
>> expected.
>> The test should be checking that waitFor does not wait longer than
>> requested.
>>
>> So shorten the timeout to a very short time (10 milliseconds) and 
>> check that
>> waitFor returns in no more than that time(plus epsilon).  It is similar
>> to the first test
>> in that section but the process is exiting.
>>
>> http://cr.openjdk.java.net/~rriggs/webrev-basic-destroy-8168517/
>
> But the first test is checking that we wait at-least as long as the 
> timeout ie no early return when we know the process is still alive.
>
> Sorry but this isn't making sense to me. The original problem is that 
> waitFor(8) has timed out and we proceeded to call exitValue() while 
> the process is still alive. If the process had in fact terminated then 
> we would have hit the (end-start) check and failed due to a timeout. 
> So what exactly are we trying to fix here? Do we simply prefer to fail 
> due to timeout rather than have exitValue() throw IllegalStateException?
calling exitValue was just additional debugging info; but the test would 
have failed the timeout condition later.
So the test is still broken, because it is not checking the correct 
timeout behavior of waitFor(timeout) and instead
is checking how long it takes the OS to destroy.  That's not interesting.
> If so then check for waitFor(8) timing out, but leave the timeout 
> value at 8 seconds - just avoid the call to exitValue() if a time-out 
> occurred. Otherwise if we want to avoid timing out we either bump the 
> timeout to some value > 8 to accommodate the load problem, or we don't 
> even bother doing waitFor after the destroy().
Lengthening the time isn't interesting either because it is only testing 
that it returns
when the process has exited, not whether the timeout is hit at the right 
time.

So I guess, its time to remove the whole test case on a destroyed process.

Roger

>
> I'm really unclear what this is trying to test, and what a failure 
> would indicate.
>
> Thanks,
> David
>
>> Thanks, Roger
>>
>>
>>>
>>> Cheers,
>>> David
>>>
>>>
>>>> Thanks, Roger
>>>>> David
>>>>>
>>>>>>
>>>>>> Roger
>>>>>>
>>>>>>>
>>>>>>> David
>>>>>>>
>>>>>>>> I contemplated increasing the timeout but given the issue is 
>>>>>>>> system
>>>>>>>> loading
>>>>>>>> I didn't have a good idea what to raise it to. 30sec, 1 min, 2 
>>>>>>>> min.
>>>>>>>> and the harness timeout is 2min.
>>>>>>>>
>>>>>>>> Roger
>>>>>>>>
>>>>>>>>>
>>>>>>>>> David
>>>>>>>>>
>>>>>>>>>> Webrev:
>>>>>>>>>> http://cr.openjdk.java.net/~rriggs/webrev-basic-destroy-8168517/
>>>>>>>>>>
>>>>>>>>>> Thanks, Roger
>>>>>>>>>>
>>>>>>>>
>>>>>>
>>>>
>>