/*
 * Copyright (c) 2017, Red Hat Inc. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package org.openjdk.gcbench.fragger;

import org.openjdk.gcbench.tests.Sequence;
import org.openjdk.jmh.annotations.*;
import org.openjdk.jmh.infra.Blackhole;
import org.openjdk.jmh.profile.SafepointsProfiler;
import org.openjdk.jmh.results.Result;
import org.openjdk.jmh.results.RunResult;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.RunnerException;
import org.openjdk.jmh.runner.options.*;

import java.io.PrintStream;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;


@Warmup(iterations = 0)
@Measurement(iterations = 1, time = 1)
@Fork(1)
@BenchmarkMode(Mode.SingleShotTime)
@OutputTimeUnit(TimeUnit.SECONDS)
@Threads(8)
@State(Scope.Thread)
public class LRUFragger {

    static final int PAYLOAD_SIZE = 4096;
    static final long TARGET_ALLOCS = 256L * 1024 * 1024 * 1024;

    @Param({"1000"})
    int size;

    Map<Object, Object> cache;
    int keyCount;

    @Setup
    public void setup() {
        cache = new LinkedHashMap<Object, Object>(size*4/3, 0.75f, true) {
            @Override
            protected boolean removeEldestEntry(Map.Entry<Object, Object> eldest) {
                return size() > size;
            }
        };
        keyCount = (int) (size * (1D / 0.8D)); // 80% hit rate
        for (int c = 0; c < size; c++) {
            cache.put("Key " + c, new byte[PAYLOAD_SIZE]);
        }
    }

    @Benchmark
    public void test(Blackhole bh) {
        long allocs = 0;
        while (allocs < TARGET_ALLOCS) {
            int idx = ThreadLocalRandom.current().nextInt(keyCount);
            Object k = "Key " + idx;
            Object o = cache.get(k);
            if (o == null) {
                o = new byte[PAYLOAD_SIZE];
                allocs += PAYLOAD_SIZE;
                cache.put(k, o);
            }
            bh.consume(o);
        }
    }

    public static void main(String... args) throws RunnerException {
        Options parent = new OptionsBuilder()
                .detectJvmArgs()
                .jvmArgsAppend("-Xmx100g", "-Xms100g", "-XX:MaxGCPauseMillis=10", "-XX:+AlwaysPreTouch", "-XX:-UseBiasedLocking", "-XX:+UnlockDiagnosticVMOptions", "-XX:GuaranteedSafepointInterval=10000000")
                .include(LRUFragger.class.getCanonicalName())
                .verbosity(VerboseMode.SILENT)
                .addProfiler(SafepointsProfiler.class)
                .timeout(TimeValue.hours(1))
//                .warmupIterations(5)
                //.warmupTime(TimeValue.seconds(10))
//                .warmupTime(TimeValue.seconds(5))
//                .measurementIterations(5)
                //.measurementTime(TimeValue.seconds(10))
//                .measurementTime(TimeValue.seconds(5))
//                .threads(8)
                .build();

        PrintStream pw = System.out;

//        Sequence sizeSeq = Sequence.steps(0, 24_000_000, 20); // for 100 GB
        Sequence sizeSeq = Sequence.steps(0, 3_000_000, 20); // for 100 GB, 8 threads
//        Sequence sizeSeq = Sequence.steps(0, 2_400_000, 10);  // for 10 GB
//        Sequence sizeSeq = Sequence.predefined(1_000_000);

//        for (String gc : new String[]{"-XX:+UseParallelGC"}) {
        for (String gc : new String[]{"-XX:+UseShenandoahGC", "-XX:+UseParallelGC", "-XX:+UseG1GC", "-XX:+UseConcMarkSweepGC"}) {
            for (Object size : sizeSeq) {
                if (size.toString().equals("0")) continue;

                Options opt = new OptionsBuilder()
                        .parent(parent)
                        .jvmArgsPrepend(gc)
                        .param("size", size.toString())
                        .build();

                try {
                    RunResult res = new Runner(opt).runSingle();
                    Result pr = res.getPrimaryResult();
                    Map<String, Result> sec = res.getSecondaryResults();

                    pw.printf("%10s, %30s,      %10.3f, %10.3f,     %5.0f, %10.3f,     %10.3f, %10.3f,       %10.3f, %10.3f, %10.3f, %10.3f, %10.3f, %10.3f, %10.3f, %10.3f%n",
                            size.toString(),
                            gc,

                            pr.getScore(),
                            pr.getScoreError(),

                            sec.get("·safepoints.pause.count").getScore(),
                            sec.get("·safepoints.pause").getScore(),

                            sec.get("·safepoints.interval").getScore(),
                            sec.get("·safepoints.pause.avg").getScore(),

                            sec.get("·safepoints.pause.p0.00").getScore(),
                            sec.get("·safepoints.pause.p0.50").getScore(),
                            sec.get("·safepoints.pause.p0.90").getScore(),
                            sec.get("·safepoints.pause.p0.95").getScore(),
                            sec.get("·safepoints.pause.p0.99").getScore(),
                            sec.get("·safepoints.pause.p0.999").getScore(),
                            sec.get("·safepoints.pause.p0.9999").getScore(),
                            sec.get("·safepoints.pause.p1.00").getScore()
                    );
                } catch (RunnerException e) {
                    // okay
                }
            }
        }
    }


}