3 ms·

Where did you get the 1% figure from? HotSpot has millions of lines of C++, that seems far too low. Graal doesn't affect memory management. It's a JIT compiler

Where did you get the 1% figure from? HotSpot has millions of lines of C++, that seems far too low. Graal doesn't affect memory management. It's a JIT compiler, not a GC. Although there's a relatively simple GC written in SystemJava for native images, G1, ZGC and Parallel will continue to be the standard GCs in the regular JVM for the foreseeable future and they are all written in C++.

taeric 4y ago
To add to your question, assuming the tooling at github is ok, it has ~20% as c/c++ for https://github.com/openjdk/jdk https://github.com/openjdk/jdk. I would think most of that would be concentrated in the hotspot code, but I don't know. Would be delighted to know what the original post was referring to.
- fathyb 4y ago
  I think the entirety of Hotspot is written in C++ [0]? The standard library in the JDK is mostly written in Java, but the VM itself with the GC and JIT code is in C++, which makes sense. If you do not count the standard library as part of the JVM (but part of the JDK), then the JVM is written mostly in C++. [0]: https://github.com/openjdk/jdk/tree/master/src/hotspot https://github.com/openjdk/jdk/tree/master/src/hotspot
  - taeric 4y ago
    That definitely matches my read of the source. Would still be delighted to know there is something else going on, though. :D
    - samus 4y ago
      Because of its inherent memory safety, Java is attractive for anything in the JVM which is not strictly necessary to be coded in C/C++ for some reason (raw performance, low-level, or OS-specific). With Projects Valhalla ann Panama around the corner, there will be even less hard reasons going forward. Also, C/C++ compilers can be tricky dependencies at times.