apangin

// Replaces implementation of Unsafe.allocateMemory/freeMemory
// to avoid long time-to-safepoint pauses.
//
// Compile: gcc -O3 -fno-omit-frame-pointer -fPIC -shared -olibunmalloc.so unmalloc.c
//
// Usage:   java -agentpath:/path/to/libunmalloc.so ...

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

apangin

import sun.jvm.hotspot.debugger.Address;
import sun.jvm.hotspot.runtime.VM;
import sun.jvm.hotspot.tools.Tool;

import java.io.IOException;
import java.io.RandomAccessFile;

/**
 * Changes -XX:MaxJavaStackTraceDepth flag to 1000000 in runtime
 * without restarting the JVM.

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

package string;

import org.openjdk.jmh.annotations.*;

import java.util.Random;
import java.util.concurrent.TimeUnit;

@BenchmarkMode(Mode.AverageTime)
@Fork(1)
@State(Scope.Thread)

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

/*
 * Copyright 2018 Andrei Pangin
 *
 * This is a specialized Java port of the FlameGraph script available at
 * https://github.com/brendangregg/FlameGraph/blob/master/flamegraph.pl
 *
 * Copyright 2016 Netflix, Inc.
 * Copyright 2011 Joyent, Inc.  All rights reserved.
 * Copyright 2011 Brendan Gregg.  All rights reserved.
 *

apangin

// Compile:
//     gcc -shared -fPIC -olibsighandle.so sighandle.c
//
// Run:
//     java -agentpath:/path/to/libsighandle.so ...
//     kill -37 <pid>

#include <signal.h>
#include <stdlib.h>
#include <unistd.h>

apangin

package bench;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;

import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ThreadLocalRandom;

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

package map;

import java.io.PrintStream;
import java.util.Base64;
import java.util.concurrent.ThreadLocalRandom;

public class MapGenerator {

    public static void main(String[] args) throws Exception {
        try (PrintStream out = new PrintStream("in.txt")) {