/*

 * Copyright (c) 2015, 2019 Oracle and/or its affiliates. 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.

 *

 * 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.bench.vm.lang;

import java.util.concurrent.TimeUnit;

import org.openjdk.jmh.annotations.Benchmark;

import org.openjdk.jmh.annotations.BenchmarkMode;

import org.openjdk.jmh.annotations.Mode;

import org.openjdk.jmh.annotations.OutputTimeUnit;

import org.openjdk.jmh.annotations.Param;

import org.openjdk.jmh.annotations.Scope;

import org.openjdk.jmh.annotations.State;

import org.openjdk.jmh.infra.Blackhole;

@State(value = Scope.Benchmark)

@BenchmarkMode(Mode.AverageTime)

@OutputTimeUnit(TimeUnit.NANOSECONDS)

public class ThrowableRuntimeMicros {

    // TestStack will add this number of calls to the call stack

    @Param({"4", "100", "1000"})

    // For more thorough testing, consider:

    // @Param({"4", "10", "100", "256", "1000"})

    public int depth;

    /** Build a call stack of a given size, then run trigger code in it.

      * (Does not account for existing frames higher up in the JMH machinery).

      */

    static class TestStack {

        final long fence;

        long current;

        final Runnable trigger;

        TestStack(long max, Runnable trigger) {

            this.fence = max;

            this.current = 0;

            this.trigger = trigger;

        }

        public void start() {

            one();

        }

        public void one() {

            if (check()) {

                two();

            }

        }

        void two() {

            if (check()) {

                three();

            }

        }

        private void three() {

            if (check()) {

                one();

            }

        }

        boolean check() {

            if (++current == fence) {

                trigger.run();

                return false;

            } else {

                return true;

            }

        }

    }

    @Benchmark

    public void testThrowableInit(Blackhole bh) {

        final Blackhole localBH = bh;

        final boolean[] done = {false};

        new TestStack(depth, new Runnable() {

            public void run() {

                localBH.consume(new Throwable());

                done[0] = true;

            }

        }).start();

        if (!done[0]) {

            throw new RuntimeException();

        }

    }

    @Benchmark

    public void testThrowableGetStackTrace(Blackhole bh) {

        final Blackhole localBH = bh;

        final boolean[] done = {false};

        new TestStack(depth, new Runnable() {

            public void run() {

                localBH.consume(new Throwable().getStackTrace());

                done[0] = true;

            }

        }).start();

        if (!done[0]) {

            throw new RuntimeException();

        }

    }

    @Benchmark

    public void testThrowableSTEtoString(Blackhole bh) {

        final Blackhole localBH = bh;

        final boolean[] done = {false};

        new TestStack(depth, new Runnable() {

            public void run() {

                Throwable t = new Throwable();

                for (StackTraceElement ste : t.getStackTrace()) {

                    localBH.consume(ste.toString());

                }

                done[0] = true;

            }

        }).start();

        if (!done[0]) {

            throw new RuntimeException();

        }

    }

}