More reliable compressed-oops patch for JOL and some simple improvements [Patch Linked]

[Aleksey Shipilev]

On 09/10/2014 11:18 AM, serkan özal wrote:
> As I seen, there are two problems/disadvantages with Hotspot SA:
> * Process attach problem on MacOSX

Do we really need to attach? Can we just poke the named constant from SA
jar? Asking seriously since I haven't looked what's in there.

> * "sa-jdi.jar" version must be same with current JVM version. For
> example, if the program is run on Java 7, "sa-jdi.jar" for Java 7
> must be used. "sa-jdi.jar" of Java 6 is not work on Java 7. But to be
> sure, I will check it again.

Well, that is the whole point of SA, right? We pack the internal VM
information in a separate JAR, which we can then reference from Java.

> However there are three advantages of Hotspot SA:
> * We can always be sure that we get right compressed-oops values since they are directly taken by JVM
> * For future works, Hotspot SA gives us more opportunities to play on JVM :)
> * Less complex code 

Yes.

-Aleksey.