RFR(M): 7033917: closed/compiler/6507107/HeapwalkingTest.java sometimes works too long

[Morris Meyer]

Folks,

During the nightly testing we have a class of bugs that crop up with 
compiler flags that change the performance dynamic of the test, such as 
-Xcomp and -XX:+DeoptimizeALot.

Instead of tweaking the test parameters, I have created an Estimator 
class that takes a work List - and creates an Iterator that is looking 
at the expiration clock for the test.  Instead of the test failing out 
for taking too much time for an arbitrary number of iterations, the 
iterator ends, and Estimator will produce a timeout factor suitable for 
the -Dtest.timeout.factor flag.

I've added an EstimatorTest to testlibrary_tests that tests the 
Estimator with three scenarios, too much time, not enough time and just 
enough time.

This test has also been through JPRT.   The changes HeapwalkingTest will 
be sent out for review to the closed list.

Thanks much,

         --morris meyer


WEBREV - http://cr.openjdk.java.net/~morris/JDK-7033917-hotspot.01
JBS - https://bugs.openjdk.java.net/browse/JDK-7033917