| /* |
| * Copyright (c) 2016, 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.serviceprovider; |
| |
| import java.util.Iterator; |
| import java.util.ServiceConfigurationError; |
| import java.util.ServiceLoader; |
| |
| import jdk.vm.ci.services.JVMCIPermission; |
| import jdk.vm.ci.services.Services; |
| |
| /** |
| * A mechanism for accessing service providers that abstracts over whether Graal is running on |
| * JVMCI-8 or JVMCI-9. In JVMCI-8, a JVMCI specific mechanism is used to lookup services via the |
| * hidden JVMCI class loader. in JVMCI-9, the standard {@link ServiceLoader} mechanism is used. |
| */ |
| public final class GraalServices { |
| |
| private GraalServices() { |
| } |
| |
| public static final boolean Java8OrEarlier = System.getProperty("java.specification.version").compareTo("1.9") < 0; |
| |
| /** |
| * Gets an {@link Iterable} of the providers available for a given service. |
| * |
| * @throws SecurityException if on JDK8 and a security manager is present and it denies |
| * {@link JVMCIPermission} |
| */ |
| public static <S> Iterable<S> load(Class<S> service) { |
| assert !service.getName().startsWith("jdk.vm.ci") : "JVMCI services must be loaded via " + Services.class.getName(); |
| if (Java8OrEarlier) { |
| return Services.load(service); |
| } |
| ServiceLoader<S> iterable = ServiceLoader.load(service); |
| return new Iterable<S>() { |
| @Override |
| public Iterator<S> iterator() { |
| Iterator<S> iterator = iterable.iterator(); |
| return new Iterator<S>() { |
| @Override |
| public boolean hasNext() { |
| return iterator.hasNext(); |
| } |
| |
| @Override |
| public S next() { |
| S provider = iterator.next(); |
| // Allow Graal extensions to access JVMCI assuming they have JVMCIPermission |
| Services.exportJVMCITo(provider.getClass()); |
| return provider; |
| } |
| |
| @Override |
| public void remove() { |
| iterator.remove(); |
| } |
| }; |
| } |
| }; |
| } |
| |
| /** |
| * Gets the provider for a given service for which at most one provider must be available. |
| * |
| * @param service the service whose provider is being requested |
| * @param required specifies if an {@link InternalError} should be thrown if no provider of |
| * {@code service} is available |
| * @return the requested provider if available else {@code null} |
| * @throws SecurityException if on JDK8 and a security manager is present and it denies |
| * {@link JVMCIPermission} |
| */ |
| public static <S> S loadSingle(Class<S> service, boolean required) { |
| assert !service.getName().startsWith("jdk.vm.ci") : "JVMCI services must be loaded via " + Services.class.getName(); |
| if (Java8OrEarlier) { |
| return Services.loadSingle(service, required); |
| } |
| Iterable<S> providers = ServiceLoader.load(service); |
| S singleProvider = null; |
| try { |
| for (Iterator<S> it = providers.iterator(); it.hasNext();) { |
| singleProvider = it.next(); |
| if (it.hasNext()) { |
| throw new InternalError(String.format("Multiple %s providers found", service.getName())); |
| } |
| } |
| } catch (ServiceConfigurationError e) { |
| // If the service is required we will bail out below. |
| } |
| if (singleProvider == null) { |
| if (required) { |
| throw new InternalError(String.format("No provider for %s found", service.getName())); |
| } |
| } else { |
| // Allow Graal extensions to access JVMCI assuming they have JVMCIPermission |
| Services.exportJVMCITo(singleProvider.getClass()); |
| } |
| return singleProvider; |
| } |
| } |