/*

 * Copyright (c) 2014 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package org.openjdk.bench.vm.compiler;

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 java.util.concurrent.TimeUnit;

/**

 * Tests how well the JVM can remove stores after allocation of objects.

 */

@BenchmarkMode(Mode.AverageTime)

@OutputTimeUnit(TimeUnit.NANOSECONDS)

public class PostAllocationStores {

    /** Tests allocation with explicit stores of null/zero to all fields. */

    @Benchmark

    public Object testAllocationWithNullStores() throws Exception {

        return new TestWithNullStores();

    }

    /**

     * Tests allocation with explicit stores of non-null/non-zero to all fields. This test exists as a complement to the

     * one above.

     */

    @Benchmark

    public Object testAllocationWithNonNullStores() throws Exception {

        return new TestWithNonNullStores();

    }

    /** Tests allocation with explicit stores of null/zero to all fields, where all fields are volatile. */

    @Benchmark

    public Object testAllocationWithNullVolatileStores() throws Exception {

        return new TestWithNullVolatileStores();

    }

    /** Tests allocation without any explicit stores to any fields. */

    @Benchmark

    public Object testAllocationWithoutStores() throws Exception {

        return new TestWithoutStores();

    }

    static class TestWithNullStores {

        Object objectField1;

        Object objectField2;

        Object objectField3;

        int intField1;

        int intField2;

        long longField1;

        public TestWithNullStores() {

            objectField1 = null;

            objectField2 = null;

            objectField3 = null;

            intField1 = 0;

            intField2 = 0;

            longField1 = 0L;

        }

    }

    static class TestWithNonNullStores {

        Object objectField1;

        Object objectField2;

        Object objectField3;

        int intField1;

        int intField2;

        long longField1;

        public TestWithNonNullStores() {

            objectField1 = this;

            objectField2 = this;

            objectField3 = this;

            intField1 = 4;

            intField2 = 7;

            longField1 = 2L;

        }

    }

    static class TestWithNullVolatileStores {

        volatile Object objectField1;

        volatile Object objectField2;

        volatile Object objectField3;

        volatile int intField1;

        volatile int intField2;

        volatile long longField1;

        public TestWithNullVolatileStores() {

            objectField1 = null;

            objectField2 = null;

            objectField3 = null;

            intField1 = 0;

            intField2 = 0;

            longField1 = 0L;

        }

    }

    static class TestWithoutStores {

        Object objectField1;

        Object objectField2;

        Object objectField3;

        int intField1;

        int intField2;

        long longField1;

    }

}