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 * 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.

 *

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package org.graalvm.compiler.core.test;

import org.graalvm.compiler.loop.DefaultLoopPolicies;

import org.graalvm.compiler.loop.phases.LoopFullUnrollPhase;

import org.graalvm.compiler.nodes.StructuredGraph;

import org.graalvm.compiler.nodes.StructuredGraph.AllowAssumptions;

import org.graalvm.compiler.nodes.java.MonitorExitNode;

import org.graalvm.compiler.nodes.java.RawMonitorEnterNode;

import org.graalvm.compiler.nodes.spi.LoweringTool;

import org.graalvm.compiler.phases.common.CanonicalizerPhase;

import org.graalvm.compiler.phases.common.DeadCodeEliminationPhase;

import org.graalvm.compiler.phases.common.LockEliminationPhase;

import org.graalvm.compiler.phases.common.LoweringPhase;

import org.graalvm.compiler.phases.tiers.HighTierContext;

import org.graalvm.compiler.virtual.phases.ea.PartialEscapePhase;

import org.junit.Test;

import jdk.vm.ci.meta.ResolvedJavaMethod;

public class LockEliminationTest extends GraalCompilerTest {

    static class A {

        int value;

        public synchronized int getValue() {

            return value;

        }

    }

    static int field1;

    static int field2;

    public static void testSynchronizedSnippet(A x, A y) {

        synchronized (x) {

            field1 = x.value;

        }

        synchronized (x) {

            field2 = y.value;

        }

    }

    @Test

    public void testLock() {

        test("testSynchronizedSnippet", new A(), new A());

        StructuredGraph graph = getGraph("testSynchronizedSnippet", false);

        new CanonicalizerPhase().apply(graph, getProviders());

        new LockEliminationPhase().apply(graph);

        assertDeepEquals(1, graph.getNodes().filter(RawMonitorEnterNode.class).count());

        assertDeepEquals(1, graph.getNodes().filter(MonitorExitNode.class).count());

    }

    public static void testSynchronizedMethodSnippet(A x) {

        int value1 = x.getValue();

        int value2 = x.getValue();

        field1 = value1;

        field2 = value2;

    }

    @Test

    public void testSynchronizedMethod() {

        test("testSynchronizedMethodSnippet", new A());

        StructuredGraph graph = getGraph("testSynchronizedMethodSnippet", false);

        new CanonicalizerPhase().apply(graph, getProviders());

        new LockEliminationPhase().apply(graph);

        assertDeepEquals(1, graph.getNodes().filter(RawMonitorEnterNode.class).count());

        assertDeepEquals(1, graph.getNodes().filter(MonitorExitNode.class).count());

    }

    public void testUnrolledSyncSnippet(Object a) {

        for (int i = 0; i < 3; i++) {

            synchronized (a) {

            }

        }

    }

    @Test

    public void testUnrolledSync() {

        StructuredGraph graph = getGraph("testUnrolledSyncSnippet", false);

        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

        canonicalizer.apply(graph, getProviders());

        HighTierContext context = getDefaultHighTierContext();

        new LoopFullUnrollPhase(canonicalizer, new DefaultLoopPolicies()).apply(graph, context);

        new LockEliminationPhase().apply(graph);

        assertDeepEquals(1, graph.getNodes().filter(RawMonitorEnterNode.class).count());

        assertDeepEquals(1, graph.getNodes().filter(MonitorExitNode.class).count());

    }

    private StructuredGraph getGraph(String snippet, boolean doEscapeAnalysis) {

        ResolvedJavaMethod method = getResolvedJavaMethod(snippet);

        StructuredGraph graph = parseEager(method, AllowAssumptions.YES);

        HighTierContext context = getDefaultHighTierContext();

        CanonicalizerPhase canonicalizer = new CanonicalizerPhase();

        canonicalizer.apply(graph, context);

        createInliningPhase().apply(graph, context);

        new CanonicalizerPhase().apply(graph, context);

        new DeadCodeEliminationPhase().apply(graph);

        if (doEscapeAnalysis) {

            new PartialEscapePhase(true, canonicalizer, graph.getOptions()).apply(graph, context);

        }

        new LoweringPhase(new CanonicalizerPhase(), LoweringTool.StandardLoweringStage.HIGH_TIER).apply(graph, context);

        return graph;

    }

    public void testEscapeAnalysisSnippet(A a) {

        A newA = new A();

        synchronized (newA) {

            synchronized (a) {

                field1 = a.value;

            }

        }

        /*

         * Escape analysis removes the synchronization on newA. But lock elimination still must not

         * combine the two synchronizations on the parameter a because they have a different lock

         * depth.

         */

        synchronized (a) {

            field2 = a.value;

        }

        /*

         * Lock elimination can combine these synchronizations, since they are both on parameter a

         * with the same lock depth.

         */

        synchronized (a) {

            field1 = a.value;

        }

    }

    @Test

    public void testEscapeAnalysis() {

        StructuredGraph graph = getGraph("testEscapeAnalysisSnippet", true);

        assertDeepEquals(3, graph.getNodes().filter(RawMonitorEnterNode.class).count());

        assertDeepEquals(3, graph.getNodes().filter(MonitorExitNode.class).count());

        new LockEliminationPhase().apply(graph);

        assertDeepEquals(2, graph.getNodes().filter(RawMonitorEnterNode.class).count());

        assertDeepEquals(2, graph.getNodes().filter(MonitorExitNode.class).count());

    }

}