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5438 :: Java GC causes a crash a library Nim runtime on linux

• alexsad (orginal) [2019-11-01T11:09:11+01:00] view original

  Hi All!

  this week i tried to implement JNI library written on Nim(v.1.0.2) using templates from https://gist.github.com/jangko/48ba0b76716d0631560e5f2ff470256d and also jnim https://github.com/yglukhov/jnim but unfortunately on linux OS got error at runtime:

  No stack traceback available

  SIGSEGV: Illegal storage access. (Attempt to read from nil?)

  i recognized that it happens when Java starts GC collect.

  Steps to reproduce:

  • empty.nim (exactly absolute empty file) compile it with nim c --app:lib empty.nim
  • Sample.java compile with javac Sample.java (see code bellow)

  public class Sample
  {
    
    public static void main(String[] args)
    {
      System.load("/absolute/path/to/libempty.so");
      //System.load("absolute\\path\\to\\empty.dll");
      
      for(int j=0; j<50000; j++){
          System.out.println("Java GC starts...");
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.gc();
          System.out.println("Java GC finished...");
      }
    }
  }
  Run

  But on windows OS it works properly.

  Please any suggestion on it, perhaps additional switches for Nim compiler?

  Thanks.

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• Araq (orginal) [2019-11-01T20:22:52+01:00] view original

  Try to compile with -d:noSignalHandler, Java's GC uses signal handlers to intercept threads for collecting.

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• alexsad (orginal) [2019-11-02T12:04:41+01:00] view original

  Araq, awesome, that solves it!

  thanks a lot!

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