navyxliu

#!/usr/bin/env ruby

# do the statistics of renaissance results
#
# probably should choose gem 'enumerable-statistics' in the future.
# so far, we only need simple procedures.
#
def median(a)
  copy = a.sort
  return copy[a.size / 2]

navyxliu

//jdk9+ java -XX:+UnlockDiagnosticVMOptions -XX:AbortVMOnException=java.lang.OutOfMemoryError OOMEInThread

// OutOfMemoryError is an unchecked exception. please note that even it keeps throwing,
// it only terminates a thread but not the java process. the following command shows that OnOutOfMemoryError
// fails to react OOME from java and get stuck forever.
//
public class OOMEInThread {
    public static void main(String[] args) {
        String msg = "a long long message.";
        // write your code here

navyxliu

### Keybase proof

I hereby claim:

  * I am navyxliu on github.
  * I am xliu (https://keybase.io/xliu) on keybase.
  * I have a public key whose fingerprint is FD6D CB16 0216 060A 4F5D  B218 B9D9 34C6 1E04 7B0D

To claim this, I am signing this object:

navyxliu

//java -XX:+PrintCompilation -XX:CompileOnly=OSR::main -XX:CompileCommand=quiet  -XX:-TieredCompilation OSR
import java.io.FileWriter;   // Import the FileWriter class
import java.io.IOException;  // Import the IOException class to handle errors

class OSR {
    public static void main(String[] args) throws IOException {
        FileWriter writer = new FileWriter("/dev/null");

        for (int i=0; i<3_000_000; ++i) {
            writer.write(".");

navyxliu

{
    // See https://go.microsoft.com/fwlink/?LinkId=733558
    // for the documentation about the tasks.json format
    "version": "2.0.0",
    "tasks": [
        {
            "label": "reconfigure",
            "type": "shell",
            "command": "make reconfigure CONF=linux-x86_64-server-fastdebug LOG=info",
            "problemMatcher": [],

navyxliu

void breakpoint() {
   exit(-1); 
}

struct node {
    friend class linkedlist;
    int key;
    int value;
    node* prev, * next;

navyxliu

$cat TestHaltNode.java
import jdk.internal.misc.Unsafe;

public class TestHaltNode {
    static final Unsafe UNSAFE = Unsafe.getUnsafe();
    static boolean f;
    static int address;

    private static int getAddress() {
        return address;

navyxliu

1. git clone https://github.com/navyxliu/JavaGCworkload.git
2. sh -x ./runJava.sh 4g gc.log -XX:+UnlockExperimentalVMOptions -XX:G1LogLevel=finest -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=8 -XX:GCLogFileSize=16k $*
3. the testcase itself is in infinite mode(-1). Usually, hotspot crashes in 4 hours. 

I found jdk8u/hotspot could crash on a varienty of systems. 

eg. I got this hs_err_report on AL2012. it has glibc 2.12. btw, AL2012 is similar to RHEL6
The message looks very similiar to JDK-8190798 and JDK-8191393

#

navyxliu

recursive case. 

  4390  358             com.sun.tools.javac.comp.Resolve::findMemberType (277 bytes)
                            @ 8   com.sun.tools.javac.code.Symbol$ClassSymbol::members (16 bytes)   inline (hot)
                             \-> TypeProfile (5649/5649 counts) = com/sun/tools/javac/code/Symbol$ClassSymbol
                            @ 12   com.sun.tools.javac.code.Scope::lookup (43 bytes)   inline (hot)
                             \-> TypeProfile (5649/5649 counts) = com/sun/tools/javac/code/Scope
                              @ 34   com.sun.tools.javac.code.Scope$Entry::access$000 (5 bytes)   accessor
                            @ 45   com.sun.tools.javac.comp.Resolve::isAccessible (327 bytes)   hot method too big
                            @ 94   com.sun.tools.javac.code.Types::supertype (12 bytes)   inline (hot)

navyxliu

#Test Results (version 2)
#Sun Oct 06 23:14:31 UTC 2019
#-----testdescription-----
$file=/src/hotspot/test/vmTestbase/gc/g1/unloading/tests/unloading_anonclassloader_inMemoryCompilation_keep_class/TestDescription.java
$root=/src/hotspot/test
keywords=stress gc othervm driver
library=/vmTestbase /testlibrary /test/lib
modules=java.base/jdk.internal.misc\:+open java.base/jdk.internal.misc
requires=((vm.gc.G1) & (vm.opt.ClassUnloading \!\= false)) & (vm.opt.ClassUnloadingWithConcurrentMark \!\= false)
run=USER_SPECIFIED driver jdk.test.lib.FileInstaller . .\nUSER_SPECIFIED driver gc.g1.unloading.bytecode.GenClassesBuilder\nUSER_SPECIFIED build sun.hotspot.WhiteBox\nUSER_SPECIFIED driver ClassFileInstaller sun.hotspot.WhiteBox sun.hotspot.WhiteBox$WhiteBoxPermission\nUSER_SPECIFIED main/othervm -Xbootclasspath/a\:. -XX\:+UnlockDiagnosticVMOptions -XX\:+WhiteBoxAPI -XX\:+UseG1GC -XX\:+ExplicitGCInvokesConcurrent -Xloggc\:gc.log -XX\:-UseGCOverheadLimit gc.g1.unloading.UnloadingTest -classloadingMethod anonymous_cl