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 * 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

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 */

package org.openjdk.bench.java.lang.invoke;

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.Scope;

import org.openjdk.jmh.annotations.State;

import java.lang.invoke.ConstantCallSite;

import java.lang.invoke.MethodHandle;

import java.lang.invoke.MethodHandles;

import java.lang.invoke.MethodType;

import java.lang.invoke.MutableCallSite;

import java.lang.invoke.VolatileCallSite;

import java.util.concurrent.TimeUnit;

/**

 * This benchmark evaluates INDY performance when call sites are not changed.

 */

@BenchmarkMode(Mode.AverageTime)

@OutputTimeUnit(TimeUnit.NANOSECONDS)

@State(Scope.Thread)

public class CallSiteStable {

    /*

     * Implementation notes:

     *   - Test is calling simple method via INDY

     *   - Additional baseline includes "raw" test, calling target method directly in virtual and static modes

     */

    private static java.lang.invoke.CallSite cs;

    private static MethodHandle doCallMH;

    static {

        try {

            doCallMH = MethodHandles.lookup().findVirtual(CallSiteStable.class, "doCall", MethodType.methodType(int.class, int.class));

        } catch (NoSuchMethodException | IllegalAccessException e) {

            throw new IllegalStateException(e);

        }

    }

    private int i;

    public int doCall(int value) {

        return value + 1;

    }

    public static int doCallStatic(int value) {

        return value + 1;

    }

    @Benchmark

    public void baselineVirtual() {

        i = doCall(i);

    }

    @Benchmark

    public void baselineStatic() {

        i = doCallStatic(i);

    }

    @Benchmark

    public void testConstant() throws Throwable {

        i = (int) INDY_Constant().invokeExact(this, i);

    }

    @Benchmark

    public void testMutable() throws Throwable {

        i = (int) INDY_Mutable().invokeExact(this, i);

    }

    @Benchmark

    public void testVolatile() throws Throwable {

        i = (int) INDY_Volatile().invokeExact(this, i);

    }

    /* =========================== INDY TRAMPOLINES ============================== */

    private static MethodType MT_bsm() {

        shouldNotCallThis();

        return MethodType.methodType(java.lang.invoke.CallSite.class, MethodHandles.Lookup.class, String.class, MethodType.class);

    }

    private static MethodHandle MH_bsm_Constant() throws ReflectiveOperationException {

        shouldNotCallThis();

        return MethodHandles.lookup().findStatic(MethodHandles.lookup().lookupClass(), "bsm_Constant", MT_bsm());

    }

    private static MethodHandle MH_bsm_Mutable() throws ReflectiveOperationException {

        shouldNotCallThis();

        return MethodHandles.lookup().findStatic(MethodHandles.lookup().lookupClass(), "bsm_Mutable", MT_bsm());

    }

    private static MethodHandle MH_bsm_Volatile() throws ReflectiveOperationException {

        shouldNotCallThis();

        return MethodHandles.lookup().findStatic(MethodHandles.lookup().lookupClass(), "bsm_Volatile", MT_bsm());

    }

    private static MethodHandle INDY_Constant() throws Throwable {

        shouldNotCallThis();

        return ((java.lang.invoke.CallSite) MH_bsm_Constant().invoke(MethodHandles.lookup(), "doCall", MethodType.methodType(int.class, CallSiteStable.class, int.class))).dynamicInvoker();

    }

    private static MethodHandle INDY_Mutable() throws Throwable {

        shouldNotCallThis();

        return ((java.lang.invoke.CallSite) MH_bsm_Mutable().invoke(MethodHandles.lookup(), "doCall", MethodType.methodType(int.class, CallSiteStable.class, int.class))).dynamicInvoker();

    }

    private static MethodHandle INDY_Volatile() throws Throwable {

        shouldNotCallThis();

        return ((java.lang.invoke.CallSite) MH_bsm_Volatile().invoke(MethodHandles.lookup(), "doCall", MethodType.methodType(int.class, CallSiteStable.class, int.class))).dynamicInvoker();

    }

    public static java.lang.invoke.CallSite bsm_Constant(MethodHandles.Lookup lookup, String name, MethodType type) {

        synchronized (CallSiteStable.class) {

            if (cs == null)

                cs = new ConstantCallSite(doCallMH);

            return cs;

        }

    }

    public static java.lang.invoke.CallSite bsm_Mutable(MethodHandles.Lookup lookup, String name, MethodType type) {

        synchronized (CallSiteStable.class) {

            if (cs == null)

                cs = new MutableCallSite(doCallMH);

            return cs;

        }

    }

    public static java.lang.invoke.CallSite bsm_Volatile(MethodHandles.Lookup lookup, String name, MethodType type) {

        synchronized (CallSiteStable.class) {

            if (cs == null)

                cs = new VolatileCallSite(doCallMH);

            return cs;

        }

    }

    private static void shouldNotCallThis() {

        // if this gets called, the transformation has not taken place

        throw new AssertionError("this code should be statically transformed away by Indify");

    }

}