Upgrade to JDK 11

[Yrp]

JDK 11 support is almost impossible. Java-tron should stay at JDK8.

See-also: andelf/opentron#36

Originally posted by @andelf in #3528 (comment)

[Yrp]

👏 @andelf Hi, guys. Let's talk about JDK11 here.

1. Has it been tested on both Oracle JDK11 and OpenJDK11?
2. If the difference is only in floating-point numbers, is it possible to solve the problem by porting the JDK8 code to JDK11 to customize the JDK11?
3. Or fix the problem by plugging in the JNI library.

[andelf]

Assembly code solves.

https://github.com/opentron/opentron/blob/6e6d9571b45838bbbfcecf9e6ba5892a29c131ec/opentron/src/manager/executor/actuators/exchange.rs#L549-L567

NOTE: The original implementation in JDK8 is also low level 8087 FPU code. In Cpp, but more like assembly code.

[andelf]

Not yet to know if there's any other misuse of Math.

You should test the ported code at least by syncing from the genesis block to the current head.

[andelf]

Softfp will solve all this misused mess. Considering java-tron is already a slow implementation, it is not acceptable.

[Yrp]

The first step is to test whether ZGC can bring performance improvements, and the second step is to work out some details.

[Yrp]

In addition to Math.pow(), other fp methods need to be tested as well.

[Benson0224]

Close this issue as no feedback for a long time, feel free to reopen it if you still see the issue. thanks.