Mercurial > hg > graal-compiler
view graal/com.oracle.jvmci.service/src/com/oracle/jvmci/service/Services.java @ 21680:902a6399353b
Merge.
author | Thomas Wuerthinger <thomas.wuerthinger@oracle.com> |
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date | Wed, 03 Jun 2015 01:11:56 +0200 |
parents | 2e8c01def9a5 |
children | 55058b8000ea |
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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 * or visit www.oracle.com if you need additional information or have any * questions. */ package com.oracle.jvmci.service; import java.util.*; import sun.reflect.*; /** * A mechanism on top of the standard {@link ServiceLoader} that enables JVMCI enabled runtime to * efficiently load services marked by {@link Service}. This is important to avoid the performance * overhead of the standard service loader mechanism for services loaded in the runtime * initialization process. */ public class Services { /** * Determines whether to suppress the {@link NoClassDefFoundError} raised if a service * implementation class specified in a {@code <jre>/jvmci/services/*} file is missing. */ private static final boolean SuppressNoClassDefFoundError = Boolean.getBoolean("jvmci.service.suppressNoClassDefFoundError"); private static final ClassValue<List<Service>> cache = new ClassValue<List<Service>>() { @Override protected List<Service> computeValue(Class<?> type) { try { return Arrays.asList(getServiceImpls(type)); } catch (NoClassDefFoundError e) { if (SuppressNoClassDefFoundError) { return Collections.emptyList(); } throw e; } } }; /** * Gets an {@link Iterable} of the implementations available for a given service. * * @throws SecurityException if a security manager is present and it denies * <tt>{@link RuntimePermission}("jvmciServices")</tt> */ @SuppressWarnings("unchecked") @CallerSensitive public static <S> Iterable<S> load(Class<S> service) { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new RuntimePermission("jvmciServices")); } if (Service.class.isAssignableFrom(service)) { try { return (Iterable<S>) cache.get(service); } catch (UnsatisfiedLinkError e) { // Fall back to standard ServiceLoader } } // Need to use the ClassLoader of the caller ClassLoader cl = Reflection.getCallerClass().getClassLoader(); return ServiceLoader.load(service, cl); } /** * Gets the implementation for a given service for which at most one implementation must be * available. * * @param service the service whose implementation is being requested * @param required specifies if an {@link InternalError} should be thrown if no implementation * of {@code service} is available * @throws SecurityException if a security manager is present and it denies * <tt>{@link RuntimePermission}("jvmciServices")</tt> */ @SuppressWarnings("unchecked") @CallerSensitive public static <S> S loadSingle(Class<S> service, boolean required) { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new RuntimePermission("jvmciServices")); } Iterable<S> impls; if (Service.class.isAssignableFrom(service)) { try { impls = (Iterable<S>) cache.get(service); } catch (UnsatisfiedLinkError e) { // Fall back to standard ServiceLoader impls = null; } } else { impls = null; } if (impls == null) { // Need to use the ClassLoader of the caller ClassLoader cl = Reflection.getCallerClass().getClassLoader(); impls = ServiceLoader.load(service, cl); } S singleImpl = null; for (S impl : impls) { if (singleImpl != null) { throw new InternalError(String.format("Multiple %s implementations found: %s, %s", service.getName(), singleImpl.getClass().getName(), impl.getClass().getName())); } singleImpl = impl; } if (singleImpl == null && required) { String javaHome = System.getProperty("java.home"); String vmName = System.getProperty("java.vm.name"); Formatter errorMessage = new Formatter(); errorMessage.format("The VM does not expose required service %s.%n", service.getName()); errorMessage.format("Currently used Java home directory is %s.%n", javaHome); errorMessage.format("Currently used VM configuration is: %s", vmName); throw new UnsupportedOperationException(errorMessage.toString()); } return singleImpl; } static { Reflection.registerMethodsToFilter(Services.class, "getServiceImpls"); Reflection.registerFieldsToFilter(Services.class, "cache"); } private static native <S> S[] getServiceImpls(Class<?> service); }