Mercurial > hg > graal-jvmci-8
view jvmci/jdk.vm.ci.services/src/jdk/vm/ci/services/Services.java @ 24234:ea6f94ab283b default tip
Added tag jvmci-0.36 for changeset 8128b98d4736
author | Gilles Duboscq <gilles.m.duboscq@oracle.com> |
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date | Mon, 18 Sep 2017 18:49:45 +0200 |
parents | 3f81f36d2c99 |
children |
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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 jdk.vm.ci.services; import java.lang.reflect.Field; import java.util.Collections; import java.util.Formatter; import java.util.HashMap; import java.util.Map; import java.util.Properties; import java.util.ServiceLoader; import sun.misc.VM; import sun.reflect.Reflection; /** * An mechanism for accessing service providers via JVMCI. These providers are loaded via a JVMCI * class loader that is hidden from application code. Hence the {@link SecurityManager} checks in * {@link #load(Class)} and {@link #loadSingle(Class, boolean)}. */ public final class Services { private Services() { } /** * Gets the system properties saved when {@link System} is initialized. The caller must not * modify the returned value. */ public static Map<String, String> getSavedProperties() { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new JVMCIPermission()); } try { Field savedPropsField = VM.class.getDeclaredField("savedProps"); savedPropsField.setAccessible(true); Properties props = (Properties) savedPropsField.get(null); Map<String, String> res = new HashMap<>(props.size()); for (Map.Entry<Object, Object> e : props.entrySet()) { res.put((String) e.getKey(), (String) e.getValue()); } return res; } catch (Exception e) { throw new InternalError(e); } } /** * Causes the JVMCI subsystem to be initialized if it isn't already initialized. */ public static void initializeJVMCI() { try { Class.forName("jdk.vm.ci.runtime.JVMCI", true, Services.getJVMCIClassLoader()); } catch (ClassNotFoundException e) { throw new InternalError(e); } } private static boolean jvmciEnabled = true; private static <S> Iterable<S> load0(Class<S> service) { if (jvmciEnabled) { ClassLoader cl = null; try { cl = getJVMCIClassLoader(); return ServiceLoader.load(service, cl); } catch (UnsatisfiedLinkError e) { jvmciEnabled = false; } catch (InternalError e) { if (e.getMessage().equals("JVMCI is not enabled")) { jvmciEnabled = false; } else { throw e; } } } return Collections.emptyList(); } /** * Performs any required security checks and dynamic reconfiguration to allow the module of a * given class to access the classes in the JVMCI module. * * Note: This API exists to provide backwards compatibility for JVMCI clients compiled against a * JDK release earlier than 9. * * @param requestor a class requesting access to the JVMCI module for its module * @throws SecurityException if a security manager is present and it denies * {@link JVMCIPermission} */ public static void exportJVMCITo(Class<?> requestor) { // There are no modules in JVMCI-8. } /** * Gets an {@link Iterable} of the JVMCI providers available for a given service. * * @throws SecurityException if a security manager is present and it denies <tt> * {@link RuntimePermission}("jvmci")</tt> */ public static <S> Iterable<S> load(Class<S> service) { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new JVMCIPermission()); } return load0(service); } /** * Gets the JVMCI 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 * @throws SecurityException if a security manager is present and it denies <tt> * {@link RuntimePermission}("jvmci")</tt> */ public static <S> S loadSingle(Class<S> service, boolean required) { SecurityManager sm = System.getSecurityManager(); if (sm != null) { sm.checkPermission(new JVMCIPermission()); } Iterable<S> providers = load0(service); S singleProvider = null; for (S provider : providers) { if (singleProvider != null) { throw new InternalError(String.format("Multiple %s providers found: %s, %s", service.getName(), singleProvider.getClass().getName(), provider.getClass().getName())); } singleProvider = provider; } if (singleProvider == 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 singleProvider; } static { Reflection.registerMethodsToFilter(Services.class, "getJVMCIClassLoader"); } /** * Gets the JVMCI class loader. * * @throws InternalError with the {@linkplain Throwable#getMessage() message} * {@code "JVMCI is not enabled"} iff JVMCI is not enabled */ private static native ClassLoader getJVMCIClassLoader(); }