RFR(S/M): 8150646: Add support for blocking compiles through whitebox API

[Vladimir Kozlov]

You are adding parameter which is used only for testing.
Can we have callback(or check field) into WB instead? Similar to 
WhiteBox::compilation_locked.

Thanks,
Vladimir

On 2/25/16 7:01 AM, Nils Eliasson wrote:
> Hi,
>
> Please review this change that adds support for blocking compiles in the
> whitebox API. This enables simpler less time consuming tests.
>
> Motivation:
> * -XX:-BackgroundCompilation is a global flag and can be time consuming
> * Blocking compiles removes the need for waiting on the compile queue to
> complete
> * Compiles put in the queue may be evicted if the queue grows to big -
> causing indeterminism in the test
> * Less VM-flags allows for more tests in the same VM
>
> Testing:
> Posting a separate RFR for test fix that uses this change. They will be
> pushed at the same time.
>
> RFE: https://bugs.openjdk.java.net/browse/JDK-8150646
> JDK rev: http://cr.openjdk.java.net/~neliasso/8150646/webrev_jdk.01/
> Hotspot rev: http://cr.openjdk.java.net/~neliasso/8150646/webrev.02/
>
> Best regards,
> Nils Eliasson