RFR: 8219149: ProcessTools.ProcessBuilder should print timing info for subprocesses

[Kim Barrett]

> On May 29, 2019, at 5:56 PM, Leonid Mesnik <leonid.mesnik at oracle.com> wrote:
> 
> Looks good.

Thanks.

> 
> Leonid
> 
> On 5/29/19 10:24 AM, Kim Barrett wrote:
>> [I’m not completely sure where this RFR should be sent, but core-libs-dev
>> and hotspot-dev seems likely to get reasonable coverage of those who
>> might care.]
>> 
>> Please review this change to the test library to add some "logging"
>> output to tests that spawn a child process to perform the test and
>> then analyze that child's output.  We are seeing occasional timeouts
>> in such tests whose cause is hard to pin down.  It's not clear whether
>> the excess time is in the child or instead some problem in the testing
>> framework.  The new logging output provides timestamps for (1) the
>> start of output collection from the child, (2) the start of waiting
>> for the child to terminate, and (3) the child's termination.  This
>> should be enough to determine whether the child is taking too long,
>> and hint at where (e.g. termination or not).
>> 
>> CR:
>> https://bugs.openjdk.java.net/browse/JDK-8219149
>> 
>> Webrev:
>> http://cr.openjdk.java.net/~kbarrett/8219149/open.00/
>> 
>> Testing:
>> Local hs-tier1 and verified the expected logging output is present.
>> mach5 tier1-3 to ensure there aren't any "obvious" unexpected problems
>> caused by the new logging.  (It seems unlikely, but...)