apangin

#include <jvmti.h>
#include <stdio.h>

static jvmtiIterationControl JNICALL
heap_callback(jlong class_tag, jlong size, jlong* tag_ptr, void* user_data) {
    *tag_ptr = 1;
    return JVMTI_ITERATION_CONTINUE;
}

JNIEXPORT jint JNICALL Agent_OnAttach(JavaVM* vm, char* options, void* reserved) {

apangin

public class HeapIterator {

    static {
        System.loadLibrary("heapIterator");
    }

    private static native void printStrings();

    public static void main(String[] args) throws Exception {
        printStrings();

apangin

_hashCode                               java/lang/Object.hashCode()I
_getClass                               java/lang/Object.getClass()Ljava/lang/Class;
_clone                                  java/lang/Object.clone()Ljava/lang/Object;
_notify                                 java/lang/Object.notify()V
_notifyAll                              java/lang/Object.notifyAll()V
_dabs                                   java/lang/Math.abs(D)D
_dsin                                   java/lang/Math.sin(D)D
_dcos                                   java/lang/Math.cos(D)D
_dtan                                   java/lang/Math.tan(D)D
_datan2                                 java/lang/Math.atan2(DD)D

apangin

_hashCode                               java/lang/Object.hashCode()I
_getClass                               java/lang/Object.getClass()Ljava/lang/Class;
_clone                                  java/lang/Object.clone()Ljava/lang/Object;
_dabs                                   java/lang/Math.abs(D)D
_dsin                                   java/lang/Math.sin(D)D
_dcos                                   java/lang/Math.cos(D)D
_dtan                                   java/lang/Math.tan(D)D
_datan2                                 java/lang/Math.atan2(DD)D
_dsqrt                                  java/lang/Math.sqrt(D)D
_dlog                                   java/lang/Math.log(D)D

apangin

import java.util.Comparator;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

// See https://twitter.com/tagir_valeev/status/1402089474805354499
public class StringBuilderHash {

apangin

import java.util.Random;

public abstract class PowerAlgorithm {

    public abstract long power(int x, int y);

    static class NaivePower extends PowerAlgorithm {
        @Override
        public long power(int x, int y) {
            long result = 1;

apangin

/*
 * Copyright 2020 Andrei Pangin
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software

apangin

/*
 * Compile: gcc -I $JAVA_HOME/include -I $JAVA_HOME/include/linux -shared -fPIC -O3 -olibrafpatch.so -Wl,-soname,librafpatch.so rafpatch.c $JAVA_HOME/lib/amd64/libjava.so
 * Run:     java -agentpath:/path/to/librafpatch.so MainClass
 */

#include <jvmti.h>
#include <jni.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>

apangin

// Compile: gcc -O2 -fPIC -shared -o libproccount.so proccount.c
// Run:     LD_PRELOAD=/path/to/libproccount.so java args

#define _GNU_SOURCE
#include <sched.h>
#include <unistd.h>

static int online_cpus;

__attribute__((constructor))

apangin

import java.lang.reflect.Method;
import java.util.Arrays;

public class Bytecodes {

    static {
        System.loadLibrary("bytecodes");
    }

    private static native byte[] getBytecodes(Method method);