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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

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 * under the terms of the GNU General Public License version 2 only, as

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 *

 * 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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/**

 * @test

 * @summary Verifies the JVMTI GetAllModules API

 * @library /test/lib

 * @run main/othervm -agentlib:JvmtiGetAllModulesTest JvmtiGetAllModulesTest

 *

 */

import java.lang.reflect.Layer;

import java.lang.reflect.Module;

import java.lang.module.ModuleReference;

import java.lang.module.ModuleFinder;

import java.lang.module.ModuleReader;

import java.lang.module.ModuleDescriptor;

import java.lang.module.Configuration;

import java.util.Arrays;

import java.util.Set;

import java.util.Map;

import java.util.function.Supplier;

import java.util.Objects;

import java.util.Optional;

import java.net.URI;

import java.util.HashSet;

import java.util.HashMap;

import java.util.stream.Collectors;

import jdk.test.lib.Asserts;

public class JvmtiGetAllModulesTest {

    static class MyModuleReference extends ModuleReference {

        public MyModuleReference(ModuleDescriptor descriptor, URI uri) {

            super(descriptor, uri);

        }

        // Trivial implementation to make the class non-abstract

        public ModuleReader open() {

            return null;

        }

    }

    private static native Module[] getModulesNative();

    private static Set<Module> getModulesJVMTI() {

        Set<Module> modules = Arrays.stream(getModulesNative()).collect(Collectors.toSet());

        // JVMTI reports unnamed modules, Java API does not

        // remove the unnamed modules here, so the resulting report can be expected

        // to be equal to what Java reports

        modules.removeIf(mod -> !mod.isNamed());

        return modules;

    }

    public static void main(String[] args) throws Exception {

        final String MY_MODULE_NAME = "myModule";

        // Verify that JVMTI reports exactly the same info as Java regarding the named modules

        Asserts.assertEquals(Layer.boot().modules(), getModulesJVMTI());

        // Load a new named module

        ModuleDescriptor descriptor

                = ModuleDescriptor.module(MY_MODULE_NAME).build();

        ModuleFinder finder = finderOf(descriptor);

        ClassLoader loader = new ClassLoader() {};

        Configuration parent = Layer.boot().configuration();

        Configuration cf = parent.resolveRequires(finder, ModuleFinder.of(), Set.of(MY_MODULE_NAME));

        Layer my = Layer.boot().defineModules(cf, m -> loader);

        // Verify that the loaded module is indeed reported by JVMTI

        Set<Module> jvmtiModules = getModulesJVMTI();

        for (Module mod : my.modules()) {

            if (!jvmtiModules.contains(mod)) {

                throw new RuntimeException("JVMTI did not report the loaded named module: " + mod.getName());

            }

        }

    }

    /**

     * Returns a ModuleFinder that finds modules with the given module

     * descriptors.

     */

    static ModuleFinder finderOf(ModuleDescriptor... descriptors) {

        // Create a ModuleReference for each module

        Map<String, ModuleReference> namesToReference = new HashMap<>();

        for (ModuleDescriptor descriptor : descriptors) {

            String name = descriptor.name();

            URI uri = URI.create("module:/" + name);

            ModuleReference mref = new MyModuleReference(descriptor, uri);

            namesToReference.put(name, mref);

        }

        return new ModuleFinder() {

            @Override

            public Optional<ModuleReference> find(String name) {

                Objects.requireNonNull(name);

                return Optional.ofNullable(namesToReference.get(name));

            }

            @Override

            public Set<ModuleReference> findAll() {

                return new HashSet<>(namesToReference.values());

            }

        };

    }

}