/*
 * Copyright (c) 2011, 2020, 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.graalvm.compiler.hotspot;

import jdk.vm.ci.code.Architecture;
import jdk.vm.ci.code.stack.StackIntrospection;
import jdk.vm.ci.common.InitTimer;
import jdk.vm.ci.hotspot.HotSpotCompilationRequest;
import jdk.vm.ci.hotspot.HotSpotJVMCIRuntime;
import jdk.vm.ci.hotspot.HotSpotResolvedJavaMethod;
import jdk.vm.ci.hotspot.HotSpotResolvedJavaType;
import jdk.vm.ci.hotspot.HotSpotResolvedObjectType;
import jdk.vm.ci.hotspot.HotSpotVMConfigStore;
import jdk.vm.ci.meta.JavaKind;
import jdk.vm.ci.meta.MetaAccessProvider;
import jdk.vm.ci.meta.ResolvedJavaMethod;
import jdk.vm.ci.meta.ResolvedJavaType;
import jdk.vm.ci.runtime.JVMCI;
import jdk.vm.ci.runtime.JVMCIBackend;
import jdk.vm.ci.services.Services;
import jdk.internal.vm.compiler.collections.EconomicMap;
import jdk.internal.vm.compiler.collections.EconomicSet;
import jdk.internal.vm.compiler.collections.Equivalence;
import jdk.internal.vm.compiler.collections.UnmodifiableMapCursor;
import org.graalvm.compiler.api.replacements.SnippetReflectionProvider;
import org.graalvm.compiler.api.runtime.GraalRuntime;
import org.graalvm.compiler.core.CompilationWrapper.ExceptionAction;
import org.graalvm.compiler.core.common.CompilationIdentifier;
import org.graalvm.compiler.core.common.CompilationListenerProfiler;
import org.graalvm.compiler.core.common.CompilerProfiler;
import org.graalvm.compiler.core.common.GraalOptions;
import org.graalvm.compiler.core.common.spi.ForeignCallsProvider;
import org.graalvm.compiler.core.target.Backend;
import org.graalvm.compiler.debug.Assertions;
import org.graalvm.compiler.debug.DebugContext;
import org.graalvm.compiler.debug.DebugContext.Builder;
import org.graalvm.compiler.debug.DebugContext.Description;
import org.graalvm.compiler.debug.DebugHandlersFactory;
import org.graalvm.compiler.debug.DebugOptions;
import org.graalvm.compiler.debug.DiagnosticsOutputDirectory;
import org.graalvm.compiler.debug.GlobalMetrics;
import org.graalvm.compiler.debug.GraalError;
import org.graalvm.compiler.debug.TTY;
import org.graalvm.compiler.hotspot.CompilationStatistics.Options;
import org.graalvm.compiler.hotspot.CompilerConfigurationFactory.BackendMap;
import org.graalvm.compiler.hotspot.debug.BenchmarkCounters;
import org.graalvm.compiler.hotspot.meta.HotSpotProviders;
import org.graalvm.compiler.nodes.spi.StampProvider;
import org.graalvm.compiler.options.EnumOptionKey;
import org.graalvm.compiler.options.OptionDescriptor;
import org.graalvm.compiler.options.OptionDescriptors;
import org.graalvm.compiler.options.OptionKey;
import org.graalvm.compiler.options.OptionValues;
import org.graalvm.compiler.options.OptionsParser;
import org.graalvm.compiler.phases.tiers.CompilerConfiguration;
import org.graalvm.compiler.replacements.SnippetCounter;
import org.graalvm.compiler.replacements.SnippetCounter.Group;
import org.graalvm.compiler.runtime.RuntimeProvider;
import org.graalvm.compiler.serviceprovider.GraalServices;

import java.io.PrintStream;
import java.util.ArrayList;
import java.util.EnumMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.atomic.AtomicReference;
import java.util.function.Supplier;

import static jdk.vm.ci.common.InitTimer.timer;
import static jdk.vm.ci.hotspot.HotSpotJVMCIRuntime.runtime;
import static org.graalvm.compiler.core.common.GraalOptions.GeneratePIC;
import static org.graalvm.compiler.core.common.GraalOptions.HotSpotPrintInlining;
import static org.graalvm.compiler.hotspot.GraalHotSpotVMConfigAccess.JDK;

//JaCoCo Exclude

Singleton class holding the instance of the GraalRuntime. /**
 * Singleton class holding the instance of the {@link GraalRuntime}.
 */
public final class HotSpotGraalRuntime implements HotSpotGraalRuntimeProvider {

    private static final boolean IS_AOT = Boolean.parseBoolean(Services.getSavedProperties().get("com.oracle.graalvm.isaot"));

    
A factory for a HotSpotGraalManagementRegistration injected by Target_org_graalvm_compiler_hotspot_HotSpotGraalRuntime. /**
     * A factory for a {@link HotSpotGraalManagementRegistration} injected by
     * {@code Target_org_graalvm_compiler_hotspot_HotSpotGraalRuntime}.
     */
    private static final Supplier<HotSpotGraalManagementRegistration> AOT_INJECTED_MANAGEMENT = null;

    private static boolean checkArrayIndexScaleInvariants(MetaAccessProvider metaAccess) {
        assert metaAccess.getArrayIndexScale(JavaKind.Byte) == 1;
        assert metaAccess.getArrayIndexScale(JavaKind.Boolean) == 1;
        assert metaAccess.getArrayIndexScale(JavaKind.Char) == 2;
        assert metaAccess.getArrayIndexScale(JavaKind.Short) == 2;
        assert metaAccess.getArrayIndexScale(JavaKind.Int) == 4;
        assert metaAccess.getArrayIndexScale(JavaKind.Long) == 8;
        assert metaAccess.getArrayIndexScale(JavaKind.Float) == 4;
        assert metaAccess.getArrayIndexScale(JavaKind.Double) == 8;
        return true;
    }

    private final String runtimeName;
    private final String compilerConfigurationName;
    private final HotSpotBackend hostBackend;

    public GlobalMetrics getMetricValues() {
        return metricValues;
    }

    private final GlobalMetrics metricValues = new GlobalMetrics();
    private final List<SnippetCounter.Group> snippetCounterGroups;
    private final HotSpotGC garbageCollector;

    private final EconomicMap<Class<? extends Architecture>, HotSpotBackend> backends = EconomicMap.create(Equivalence.IDENTITY);

    private final GraalHotSpotVMConfig config;

    private final Instrumentation instrumentation;

    
The options can be updated by external interfaces such as JMX. This comes with the risk that inconsistencies can arise as an OptionValues object can be cached by various parts of Graal instead of always obtaining them from this object. However, concurrent updates are never lost. /**
     * The options can be {@linkplain #setOptionValues(String[], String[]) updated} by external
     * interfaces such as JMX. This comes with the risk that inconsistencies can arise as an
     * {@link OptionValues} object can be cached by various parts of Graal instead of always
     * obtaining them from this object. However, concurrent updates are never lost.
     */
    private AtomicReference<OptionValues> optionsRef = new AtomicReference<>();

    private final DiagnosticsOutputDirectory outputDirectory;
    private final Map<ExceptionAction, Integer> compilationProblemsPerAction;

    private final CompilerProfiler compilerProfiler;

    
Params:
nameQualifier – a qualifier to be added to this runtime's name
compilerConfigurationFactory – factory for the compiler configuration CompilerConfigurationFactory.selectFactory(String, OptionValues)/**
     * @param nameQualifier a qualifier to be added to this runtime's {@linkplain #getName() name}
     * @param compilerConfigurationFactory factory for the compiler configuration
     *            {@link CompilerConfigurationFactory#selectFactory(String, OptionValues)}
     */
    @SuppressWarnings("try")
    HotSpotGraalRuntime(String nameQualifier, HotSpotJVMCIRuntime jvmciRuntime, CompilerConfigurationFactory compilerConfigurationFactory, OptionValues initialOptions) {
        this.runtimeName = getClass().getSimpleName() + ":" + nameQualifier;
        HotSpotVMConfigStore store = jvmciRuntime.getConfigStore();
        config = GeneratePIC.getValue(initialOptions) ? new AOTGraalHotSpotVMConfig(store) : new GraalHotSpotVMConfig(store);

        // Only set HotSpotPrintInlining if it still has its default value (false).
        if (GraalOptions.HotSpotPrintInlining.getValue(initialOptions) == false && config.printInlining) {
            optionsRef.set(new OptionValues(initialOptions, HotSpotPrintInlining, true));
        } else {
            optionsRef.set(initialOptions);
        }
        OptionValues options = optionsRef.get();

        garbageCollector = getSelectedGC();

        outputDirectory = new DiagnosticsOutputDirectory(options);
        compilationProblemsPerAction = new EnumMap<>(ExceptionAction.class);
        snippetCounterGroups = GraalOptions.SnippetCounters.getValue(options) ? new ArrayList<>() : null;
        CompilerConfiguration compilerConfiguration = compilerConfigurationFactory.createCompilerConfiguration();
        compilerConfigurationName = compilerConfigurationFactory.getName();

        this.instrumentation = compilerConfigurationFactory.createInstrumentation(options);

        if (IS_AOT) {
            management = AOT_INJECTED_MANAGEMENT == null ? null : AOT_INJECTED_MANAGEMENT.get();
        } else {
            management = GraalServices.loadSingle(HotSpotGraalManagementRegistration.class, false);
        }
        if (management != null) {
            try {
                management.initialize(this, config);
            } catch (ThreadDeath td) {
                throw td;
            } catch (Throwable error) {
                TTY.println("Cannot install GraalVM MBean due to " + error.getMessage());
                management = null;
            }
        }

        BackendMap backendMap = compilerConfigurationFactory.createBackendMap();

        JVMCIBackend hostJvmciBackend = jvmciRuntime.getHostJVMCIBackend();
        Architecture hostArchitecture = hostJvmciBackend.getTarget().arch;
        try (InitTimer t = timer("create backend:", hostArchitecture)) {
            HotSpotBackendFactory factory = backendMap.getBackendFactory(hostArchitecture);
            if (factory == null) {
                throw new GraalError("No backend available for host architecture \"%s\"", hostArchitecture);
            }
            hostBackend = registerBackend(factory.createBackend(this, compilerConfiguration, jvmciRuntime, null));
        }

        for (JVMCIBackend jvmciBackend : jvmciRuntime.getJVMCIBackends().values()) {
            if (jvmciBackend == hostJvmciBackend) {
                continue;
            }

            Architecture gpuArchitecture = jvmciBackend.getTarget().arch;
            HotSpotBackendFactory factory = backendMap.getBackendFactory(gpuArchitecture);
            if (factory == null) {
                throw new GraalError("No backend available for specified GPU architecture \"%s\"", gpuArchitecture);
            }
            try (InitTimer t = timer("create backend:", gpuArchitecture)) {
                registerBackend(factory.createBackend(this, compilerConfiguration, null, hostBackend));
            }
        }

        // Complete initialization of backends
        try (InitTimer st = timer(hostBackend.getTarget().arch.getName(), ".completeInitialization")) {
            hostBackend.completeInitialization(jvmciRuntime, options);
        }
        for (HotSpotBackend backend : backends.getValues()) {
            if (backend != hostBackend) {
                try (InitTimer st = timer(backend.getTarget().arch.getName(), ".completeInitialization")) {
                    backend.completeInitialization(jvmciRuntime, options);
                }
            }
        }

        BenchmarkCounters.initialize(jvmciRuntime, options);

        assert checkArrayIndexScaleInvariants(hostJvmciBackend.getMetaAccess());

        runtimeStartTime = System.nanoTime();
        bootstrapJVMCI = config.getFlag("BootstrapJVMCI", Boolean.class);

        this.compilerProfiler = GraalServices.loadSingle(CompilerProfiler.class, false);
    }

    
Constants denoting the GC algorithms available in HotSpot. The names of the constants match the constants in the CollectedHeap::Name C++ enum. /**
     * Constants denoting the GC algorithms available in HotSpot. The names of the constants match
     * the constants in the {@code CollectedHeap::Name} C++ enum.
     */
    public enum HotSpotGC {
        // Supported GCs
        Serial(true, JDK >= 11, "UseSerialGC", true),
        Parallel(true, JDK >= 11, "UseParallelGC", true, "UseParallelOldGC", JDK < 15, "UseParNewGC", JDK < 10),
        CMS(true, JDK >= 11 && JDK <= 14, "UseConcMarkSweepGC", JDK < 14),
        G1(true, JDK >= 11, "UseG1GC", true),

        // Unsupported GCs
        Epsilon(false, JDK >= 11, "UseEpsilonGC", JDK >= 11),
        Z(false, JDK >= 11, "UseZGC", JDK >= 11),
        Shenandoah(false, JDK >= 12, "UseShenandoahGC", JDK >= 12);

        HotSpotGC(boolean supported, boolean expectNamePresent,
                        String flag1, boolean expectFlagPresent1,
                        String flag2, boolean expectFlagPresent2,
                        String flag3, boolean expectFlagPresent3) {
            this.supported = supported;
            this.expectNamePresent = expectNamePresent;
            this.expectFlagsPresent = new boolean[]{expectFlagPresent1, expectFlagPresent2, expectFlagPresent3};
            this.flags = new String[]{flag1, flag2, flag3};
        }

        HotSpotGC(boolean supported, boolean expectNamePresent, String flag, boolean expectFlagPresent) {
            this.supported = supported;
            this.expectNamePresent = expectNamePresent;
            this.expectFlagsPresent = new boolean[]{expectFlagPresent};
            this.flags = new String[]{flag};
        }

        
Specifies if this GC supported by Graal.
/**
         * Specifies if this GC supported by Graal.
         */
        final boolean supported;

        
Specifies if Enum<HotSpotGC>.name() is expected to be present in the CollectedHeap::Name C++ enum. /**
         * Specifies if {@link #name()} is expected to be present in the {@code CollectedHeap::Name}
         * C++ enum.
         */
        final boolean expectNamePresent;

        
The VM flags that will select this GC.
/**
         * The VM flags that will select this GC.
         */
        private final String[] flags;

        
Specifies which flags are expected to be present in the VM. /**
         * Specifies which {@link #flags} are expected to be present in the VM.
         */
        final boolean[] expectFlagsPresent;

        public boolean isSelected(GraalHotSpotVMConfig config) {
            boolean selected = false;
            for (int i = 0; i < flags.length; i++) {
                final boolean notPresent = false;
                if (config.getFlag(flags[i], Boolean.class, notPresent, expectFlagsPresent[i])) {
                    selected = true;
                    if (!Assertions.assertionsEnabled()) {
                        // When asserting, check that isSelected works for all flag names
                        break;
                    }
                }
            }
            return selected;
        }

        
Gets the GC matching name. 
Params:
name – the ordinal of a CollectedHeap::Name value/**
         * Gets the GC matching {@code name}.
         *
         * @param name the ordinal of a {@code CollectedHeap::Name} value
         */
        static HotSpotGC forName(int name, GraalHotSpotVMConfig config) {
            for (HotSpotGC gc : HotSpotGC.values()) {
                if (config.getConstant("CollectedHeap::" + gc.name(), Integer.class, -1, gc.expectNamePresent) == name) {
                    return gc;
                }
            }
            return null;
        }
    }

    private HotSpotGC getSelectedGC() throws GraalError {
        HotSpotGC selected = null;
        for (HotSpotGC gc : HotSpotGC.values()) {
            if (gc.isSelected(config)) {
                if (!gc.supported) {
                    throw new GraalError(gc.name() + " garbage collector is not supported by Graal");
                }
                selected = gc;
                if (!Assertions.assertionsEnabled()) {
                    // When asserting, check that isSelected works for all HotSpotGC values
                    break;
                }
            }
        }
        if (selected == null) {
            // As of JDK 9, exactly one GC flag is guaranteed to be selected.
            // On JDK 8, the default GC is Serial when no GC flag is true.
            selected = HotSpotGC.Serial;
        }
        return selected;
    }

    private HotSpotBackend registerBackend(HotSpotBackend backend) {
        Class<? extends Architecture> arch = backend.getTarget().arch.getClass();
        HotSpotBackend oldValue = backends.put(arch, backend);
        assert oldValue == null : "cannot overwrite existing backend for architecture " + arch.getSimpleName();
        return backend;
    }

    @Override
    public HotSpotProviders getHostProviders() {
        return getHostBackend().getProviders();
    }

    @Override
    public GraalHotSpotVMConfig getVMConfig() {
        return config;
    }

    @Override
    public DebugContext openDebugContext(OptionValues compilationOptions, CompilationIdentifier compilationId, Object compilable, Iterable<DebugHandlersFactory> factories, PrintStream logStream) {
        if (management != null && management.poll(false) != null) {
            if (compilable instanceof HotSpotResolvedJavaMethod) {
                HotSpotResolvedObjectType type = ((HotSpotResolvedJavaMethod) compilable).getDeclaringClass();
                if (type instanceof HotSpotResolvedJavaType) {
                    Class<?> clazz = runtime().getMirror(type);
                    if (clazz != null) {
                        try {
                            ClassLoader cl = clazz.getClassLoader();
                            if (cl != null) {
                                loaders.add(cl);
                            }
                        } catch (SecurityException e) {
                            // This loader can obviously not be used for resolving class names
                        }
                    }
                }
            }
        }

        Description description = new Description(compilable, compilationId.toString(CompilationIdentifier.Verbosity.ID));
        Builder builder = new Builder(compilationOptions, factories).//
                        globalMetrics(metricValues).//
                        description(description).//
                        logStream(logStream);
        if (compilerProfiler != null) {
            int compileId = ((HotSpotCompilationIdentifier) compilationId).getRequest().getId();
            builder.compilationListener(new CompilationListenerProfiler(compilerProfiler, compileId));
        }
        return builder.build();

    }

    @Override
    public OptionValues getOptions() {
        return optionsRef.get();
    }

    @Override
    public Group createSnippetCounterGroup(String groupName) {
        if (snippetCounterGroups != null) {
            Group group = new Group(groupName);
            snippetCounterGroups.add(group);
            return group;
        }
        return null;
    }

    @Override
    public String getName() {
        return runtimeName;
    }

    @SuppressWarnings("unchecked")
    @Override
    public <T> T getCapability(Class<T> clazz) {
        if (clazz == RuntimeProvider.class) {
            return (T) this;
        } else if (clazz == OptionValues.class) {
            return (T) optionsRef.get();
        } else if (clazz == StackIntrospection.class) {
            return (T) this;
        } else if (clazz == SnippetReflectionProvider.class) {
            return (T) getHostProviders().getSnippetReflection();
        } else if (clazz == GraalHotSpotVMConfig.class) {
            return (T) getVMConfig();
        } else if (clazz == StampProvider.class) {
            return (T) getHostProviders().getStampProvider();
        } else if (ForeignCallsProvider.class.isAssignableFrom(clazz)) {
            return (T) getHostProviders().getForeignCalls();
        }
        return null;
    }

    @Override
    public HotSpotGC getGarbageCollector() {
        return garbageCollector;
    }

    @Override
    public HotSpotBackend getHostBackend() {
        return hostBackend;
    }

    @Override
    public <T extends Architecture> Backend getBackend(Class<T> arch) {
        assert arch != Architecture.class;
        return backends.get(arch);
    }

    @Override
    public String getCompilerConfigurationName() {
        return compilerConfigurationName;
    }

    @Override
    public Instrumentation getInstrumentation() {
        return instrumentation;
    }

    private long runtimeStartTime;

    
Called from compiler threads to check whether to bail out of a compilation.
/**
     * Called from compiler threads to check whether to bail out of a compilation.
     */
    private volatile boolean shutdown;

    
Shutdown hooks that should be run on the same thread doing the shutdown.
/**
     * Shutdown hooks that should be run on the same thread doing the shutdown.
     */
    private List<Runnable> shutdownHooks = new ArrayList<>();

    
Take action related to entering a new execution phase.
Params:
phase – the execution phase being entered/**
     * Take action related to entering a new execution phase.
     *
     * @param phase the execution phase being entered
     */
    void phaseTransition(String phase) {
        if (Options.UseCompilationStatistics.getValue(optionsRef.get())) {
            CompilationStatistics.clear(phase);
        }
    }

    
Adds a Runnable that will be run when this runtime is shutdown(). The runnable will be run on the same thread doing the shutdown. All the advice for regular shutdown hooks also applies here but even more so since the hook runs on the shutdown thread. /**
     * Adds a {@link Runnable} that will be run when this runtime is {@link #shutdown()}. The
     * runnable will be run on the same thread doing the shutdown. All the advice for regular
     * {@linkplain Runtime#addShutdownHook(Thread) shutdown hooks} also applies here but even more
     * so since the hook runs on the shutdown thread.
     */
    public synchronized void addShutdownHook(Runnable hook) {
        if (!shutdown) {
            shutdownHooks.add(hook);
        }
    }

    synchronized void shutdown() {
        shutdown = true;

        for (Runnable r : shutdownHooks) {
            try {
                r.run();
            } catch (Throwable e) {
                e.printStackTrace(TTY.out);
            }
        }

        metricValues.print(optionsRef.get());

        phaseTransition("final");

        if (snippetCounterGroups != null) {
            for (Group group : snippetCounterGroups) {
                TTY.out().out().println(group);
            }
        }
        BenchmarkCounters.shutdown(runtime(), optionsRef.get(), runtimeStartTime);

        outputDirectory.close();

        shutdownLibGraal();
    }

    
Substituted by com.oracle.svm.graal.hotspot.libgraal.Target_org_graalvm_compiler_hotspot_HotSpotGraalRuntime to call jdk.internal.vm.compiler.nativeimage.VMRuntime.shutdown(). /**
     * Substituted by
     * {@code com.oracle.svm.graal.hotspot.libgraal.Target_org_graalvm_compiler_hotspot_HotSpotGraalRuntime}
     * to call {@code jdk.internal.vm.compiler.nativeimage.VMRuntime.shutdown()}.
     */
    private static void shutdownLibGraal() {
    }

    void clearMetrics() {
        metricValues.clear();
    }

    private final boolean bootstrapJVMCI;
    private boolean bootstrapFinished;

    public void notifyBootstrapFinished() {
        bootstrapFinished = true;
    }

    @Override
    public boolean isBootstrapping() {
        return bootstrapJVMCI && !bootstrapFinished;
    }

    @Override
    public boolean isShutdown() {
        return shutdown;
    }

    @Override
    public DiagnosticsOutputDirectory getOutputDirectory() {
        return outputDirectory;
    }

    @Override
    public Map<ExceptionAction, Integer> getCompilationProblemsPerAction() {
        return compilationProblemsPerAction;
    }

    // ------- Management interface ---------

    private HotSpotGraalManagementRegistration management;

    
@returns
the management object for this runtime or null/**
     * @returns the management object for this runtime or {@code null}
     */
    public HotSpotGraalManagementRegistration getManagement() {
        return management;
    }

    
Set of weak references to ClassLoaders available for resolving class names present in management action arguments. /**
     * Set of weak references to {@link ClassLoader}s available for resolving class names present in
     * management {@linkplain #invokeManagementAction(String, Object[]) action} arguments.
     */
    private final WeakClassLoaderSet loaders = new WeakClassLoaderSet(ClassLoader.getSystemClassLoader());

    
Sets or updates this object's options from names and values. 
Params:
values – the values to set. The empty string represents null which resets an option to its default value. For string type options, a non-empty value must be enclosed in double quotes.
Returns:
an array of Strings where the element at index i is names[i] if setting the denoted option succeeded, null if the option is unknown otherwise an error message describing the failure to set the option/**
     * Sets or updates this object's {@linkplain #getOptions() options} from {@code names} and
     * {@code values}.
     *
     * @param values the values to set. The empty string represents {@code null} which resets an
     *            option to its default value. For string type options, a non-empty value must be
     *            enclosed in double quotes.
     * @return an array of Strings where the element at index i is {@code names[i]} if setting the
     *         denoted option succeeded, {@code null} if the option is unknown otherwise an error
     *         message describing the failure to set the option
     */
    public String[] setOptionValues(String[] names, String[] values) {
        EconomicMap<String, OptionDescriptor> optionDescriptors = getOptionDescriptors();
        EconomicMap<OptionKey<?>, Object> newValues = EconomicMap.create(names.length);
        EconomicSet<OptionKey<?>> resetValues = EconomicSet.create(names.length);
        String[] result = new String[names.length];
        for (int i = 0; i < names.length; i++) {
            String name = names[i];
            OptionDescriptor option = optionDescriptors.get(name);
            if (option != null) {
                String svalue = values[i];
                Class<?> optionValueType = option.getOptionValueType();
                OptionKey<?> optionKey = option.getOptionKey();
                if (svalue == null || svalue.isEmpty() && !(optionKey instanceof EnumOptionKey)) {
                    resetValues.add(optionKey);
                    result[i] = name;
                } else {
                    String valueToParse;
                    if (optionValueType == String.class) {
                        if (svalue.length() < 2 || svalue.charAt(0) != '"' || svalue.charAt(svalue.length() - 1) != '"') {
                            result[i] = "Invalid value for String option '" + name + "': must be the empty string or be enclosed in double quotes: " + svalue;
                            continue;
                        } else {
                            valueToParse = svalue.substring(1, svalue.length() - 1);
                        }
                    } else {
                        valueToParse = svalue;
                    }
                    try {
                        OptionsParser.parseOption(name, valueToParse, newValues, OptionsParser.getOptionsLoader());
                        result[i] = name;
                    } catch (IllegalArgumentException e) {
                        result[i] = e.getMessage();
                        continue;
                    }
                }
            } else {
                result[i] = null;
            }
        }

        OptionValues currentOptions;
        OptionValues newOptions;
        do {
            currentOptions = optionsRef.get();
            UnmodifiableMapCursor<OptionKey<?>, Object> cursor = currentOptions.getMap().getEntries();
            while (cursor.advance()) {
                OptionKey<?> key = cursor.getKey();
                if (!resetValues.contains(key) && !newValues.containsKey(key)) {
                    newValues.put(key, OptionValues.decodeNull(cursor.getValue()));
                }
            }
            newOptions = new OptionValues(newValues);
        } while (!optionsRef.compareAndSet(currentOptions, newOptions));

        return result;
    }

    
Gets the values for the options corresponding to names encoded as strings. The empty string represents null. For string type options, non-null values will be enclosed in double quotes. 
Params:
names – a list of option names
Returns:
the values for each named option. If an element in names does not denote an existing option, the corresponding element in the returned array will be null/**
     * Gets the values for the options corresponding to {@code names} encoded as strings. The empty
     * string represents {@code null}. For string type options, non-{@code null} values will be
     * enclosed in double quotes.
     *
     * @param names a list of option names
     * @return the values for each named option. If an element in {@code names} does not denote an
     *         existing option, the corresponding element in the returned array will be {@code null}
     */
    public String[] getOptionValues(String... names) {
        String[] values = new String[names.length];
        EconomicMap<String, OptionDescriptor> optionDescriptors = getOptionDescriptors();
        for (int i = 0; i < names.length; i++) {
            OptionDescriptor option = optionDescriptors.get(names[i]);
            if (option != null) {
                OptionKey<?> optionKey = option.getOptionKey();
                Object value = optionKey.getValue(getOptions());
                String svalue;
                if (option.getOptionValueType() == String.class && value != null) {
                    svalue = "\"" + value + "\"";
                } else if (value == null) {
                    svalue = "";
                } else {
                    svalue = String.valueOf(value);
                }
                values[i] = svalue;
            } else {
                // null denotes the option does not exist
                values[i] = null;
            }
        }
        return values;
    }

    private static EconomicMap<String, OptionDescriptor> getOptionDescriptors() {
        EconomicMap<String, OptionDescriptor> result = EconomicMap.create();
        for (OptionDescriptors set : OptionsParser.getOptionsLoader()) {
            for (OptionDescriptor option : set) {
                result.put(option.getName(), option);
            }
        }
        return result;
    }

    private void dumpMethod(String className, String methodName, String filter, String host, int port) throws Exception {
        EconomicSet<ClassNotFoundException> failures = EconomicSet.create();
        EconomicSet<Class<?>> found = loaders.resolve(className, failures);
        if (found.isEmpty()) {
            ClassNotFoundException cause = failures.isEmpty() ? new ClassNotFoundException(className) : failures.iterator().next();
            throw new Exception("Cannot find class " + className + " to schedule recompilation", cause);
        }
        for (Class<?> clazz : found) {
            ResolvedJavaType type = JVMCI.getRuntime().getHostJVMCIBackend().getMetaAccess().lookupJavaType(clazz);
            for (ResolvedJavaMethod method : type.getDeclaredMethods()) {
                if (methodName.equals(method.getName()) && method instanceof HotSpotResolvedJavaMethod) {
                    HotSpotResolvedJavaMethod hotSpotMethod = (HotSpotResolvedJavaMethod) method;
                    dumpMethod(hotSpotMethod, filter, host, port);
                }
            }
        }
    }

    private void dumpMethod(HotSpotResolvedJavaMethod hotSpotMethod, String filter, String host, int port) throws Exception {
        EconomicMap<OptionKey<?>, Object> extra = EconomicMap.create();
        extra.put(DebugOptions.Dump, filter);
        extra.put(DebugOptions.PrintGraphHost, host);
        extra.put(DebugOptions.PrintGraphPort, port);
        OptionValues compileOptions = new OptionValues(getOptions(), extra);
        HotSpotGraalCompiler compiler = (HotSpotGraalCompiler) runtime().getCompiler();
        compiler.compileMethod(new HotSpotCompilationRequest(hotSpotMethod, -1, 0L), false, compileOptions);
    }

    public Object invokeManagementAction(String actionName, Object[] params) throws Exception {
        if ("dumpMethod".equals(actionName)) {
            if (params.length != 0 && params[0] instanceof HotSpotResolvedJavaMethod) {
                HotSpotResolvedJavaMethod method = param(params, 0, "method", HotSpotResolvedJavaMethod.class, null);
                String filter = param(params, 1, "filter", String.class, ":3");
                String host = param(params, 2, "host", String.class, "localhost");
                Number port = param(params, 3, "port", Number.class, 4445);
                dumpMethod(method, filter, host, port.intValue());
            } else {
                String className = param(params, 0, "className", String.class, null);
                String methodName = param(params, 1, "methodName", String.class, null);
                String filter = param(params, 2, "filter", String.class, ":3");
                String host = param(params, 3, "host", String.class, "localhost");
                Number port = param(params, 4, "port", Number.class, 4445);
                dumpMethod(className, methodName, filter, host, port.intValue());
            }
        }
        return null;
    }

    private static <T> T param(Object[] arr, int index, String name, Class<T> type, T defaultValue) {
        Object value = arr.length > index ? arr[index] : null;
        if (value == null || (value instanceof String && ((String) value).isEmpty())) {
            if (defaultValue == null) {
                throw new IllegalArgumentException(name + " must be specified");
            }
            value = defaultValue;
        }
        if (type.isInstance(value)) {
            return type.cast(value);
        }
        throw new IllegalArgumentException("Expecting " + type.getName() + " for " + name + " but was " + value);
    }
}