code review request: Test case for JDK-7042126 HashMap.clone() memory leak

Alan Bateman Alan.Bateman at oracle.com
Thu Jan 31 14:05:11 UTC 2013


On 31/01/2013 09:40, David Buck wrote:
> Hi!
>
> I was curious to see what others have done in the past and took a look 
> at about 15 different testcases for memory leaks in the jdk tree and 
> basically found 3 patterns:
Another one that you'll find is tests that use jmap to look at the 
instance count of specific objects to see if they are increasing. I 
personally do not like these tests as they are too targeted, also they 
involve a second process and historically have been troublesome.

Anyway, my concern with the test as proposed is that it will might fail 
intermittently. Last year there were fixes to several issues like this, 
here are two that Eric Wang that come to mind:

http://hg.openjdk.java.net/jdk8/tl/jdk/rev/4ad204cc7433

http://hg.openjdk.java.net/jdk8/tl/jdk/rev/97eb7a4b1fdd

Adding a loop + sleep to your test should be fine for now.

I see Martin's suggestion about adding a supporting library to the test 
suite for use by tests like this. As it's something that tests in may 
areas then it may be worth exploring.

-Alan



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