RFR (S): 8006413: Add utility classes for writing better multiprocess tests in jtreg

[Dmitry Samersoff]

Christian,

On my opinion something like

import com.oracle.jtreg.tools.*

is less painful than maintain several independent implementations of the
same ideas.

-Dmitry


On 2013-01-17 18:01, Christian Törnqvist wrote:
>> Is it possible to have a library like this one included into jtreg
>> and available for everybody ?
> 
> The problem with this is that suddenly the tests have a dependency on
> jtreg. One (of many) nice things with the jtreg tests is that they
> can be run as a normal java program without the need to involve
> jtreg, making debugging and troubleshooting them a lot easier.
> 
> Best regards, Christian
> 
> -----Original Message----- From: Dmitry Samersoff Sent: den 17
> januari 2013 14:20 To: Stuart Marks Cc: Christian Törnqvist;
> hotspot-dev at openjdk.java.net; Jonathan Gibbons Subject: Re: RFR (S):
> 8006413: Add utility classes for writing better multiprocess tests in
> jtreg
> 
> Stuart,
> 
>> I work on the JDK core libraries. It turns out that there is a
>> similar library used for testing RMI.
> 
> I guess if we take close look to exising tests we would find couple
> more copies of the same ideas.
> 
> Is it possible to have a library like this one included into jtreg
> and available for everybody ?
> 
> -Dmitry
> 
> 
> On 2013-01-17 01:54, Stuart Marks wrote:
>> Hi everybody,
>> 
>> I work on the JDK core libraries. It turns out that there is a
>> similar library used for testing RMI. Take a look at 
>> jdk/test/java/rmi/testlibrary. It's been around for quite some time
>>  already, but I've been doing some maintenance on it recently.
>> (Also, it still needs more work.)
>> 
>> Since the RMI library is in the jdk repo and these test utilities
>> are in hotspot, it seems like sharing of code might be difficult.
>> But we might want to compare notes. Here are some observations and
>> comments (though not an actual code review).
>> 
>> * The use of a pair of threads (StreamPumper) to collect output
>> from the subprocess is very similar to what RMI does. See the
>> StreamPipe class in RMI's test library, which are used by the
>> JavaVM utility class. One thing I did do recently was to make sure
>> that the subprocess is waited for and the threads are joined. This
>> hadn't been done before, leading to race conditions where some
>> subprocess output was dropped.
>> 
>> * Since these threads are specifically joined, I'm not sure of the
>>  utility of making them daemon threads.
>> 
>> * My style in writing test code and test library code is to be
>> quite verbose about everything and to check every possible error
>> condition. Nothing is worse than seeing a test fail and not having
>> enough information in the log to find out why. Actually, I can
>> think of something worse: having a test pass erroneously because
>> some error condition wasn't checked. (Yes, this has happened.)
>> 
>> * Another style point is that I think it's OK for test library code
>>  just to throw exceptions out to the caller. My test code usually
>> has 'throws IOException' or even 'throws Exception' on most of the
>>  methods, including main, so having test library code throw checked
>>  exceptions is reasonable. Jtreg will catch exceptions thrown from
>> main and log them. Usually you want tests to fail quickly at the
>> point of error. So, I concur with Vitaly's concern about
>> ProcessTools handling of IOException and about letting interrupts
>> propagate.
>> 
>> * Actually I have a suggestion from Mandy Chung for RMI's
>> StreamPipe threads to catch exceptions and report them back to
>> their "parent" JavaVM. This is probably a rare occurrence but it
>> does ensure that any errors that occur here won't go unnoticed. See
>> JDK-8005827 ( 
>> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8005827 )
>> 
>> * Regarding jtreg and test library code, it's pretty simple to use.
>> In each test that uses the library code, one adds the @library tag
>> to declare the library. It's probably a good idea to add an @build
>> tag to build each library class that's used in the test. Things
>> usually work in the absence of @build tags, because of implicit
>> compilation, but it's kind of fragile.
>> 
>> Anyway, I just wanted to share some notes and ideas.
>> 
>> s'marks
>> 
>> 
>> On 1/16/13 4:34 AM, Christian Törnqvist wrote:
>>> Hi everyone,
>>> 
>>> ?
>>> 
>>> This RFE adds a few utility classes to make it a bit easier to
>>> write multi-process tests in jtreg, webrev can be found at 
>>> http://cr.openjdk.java.net/~brutisso/8006413/webrev.00/
>>> 
>>> ?
>>> 
>>> Thanks,
>>> 
>>> Christian
>>> 
> 
> 
> -- Dmitry Samersoff Oracle Java development team, Saint Petersburg,
> Russia * Give Rabbit time, and he'll always get the answer
> 


-- 
Dmitry Samersoff
Oracle Java development team, Saint Petersburg, Russia
* Give Rabbit time, and he'll always get the answer