--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jvmci/jdk.vm.ci.services/src/jdk/vm/ci/services/Services.java	Wed Dec 30 17:55:07 2015 +0100
@@ -0,0 +1,135 @@
+/*
+ * 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.util.Arrays;
+import java.util.Collections;
+import java.util.Formatter;
+import java.util.List;
+
+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() {
+    }
+
+    private static final String SUPPRESS_PROPERTY_NAME = "jvmci.service.suppressNoClassDefFoundError";
+
+    /**
+     * Determines whether to suppress the {@link NoClassDefFoundError} raised if a service provider
+     * class specified in a {@code <jre>/jvmci/services/*} file is missing.
+     */
+    private static final boolean SuppressNoClassDefFoundError = Boolean.getBoolean(SUPPRESS_PROPERTY_NAME);
+
+    private static final ClassValue<List<?>> cache = new ClassValue<List<?>>() {
+        @Override
+        protected List<?> computeValue(Class<?> type) {
+            try {
+                return Arrays.asList(getServiceImpls(type));
+            } catch (NoClassDefFoundError e) {
+                if (SuppressNoClassDefFoundError) {
+                    return Collections.emptyList();
+                } else {
+                    NoClassDefFoundError newEx = new NoClassDefFoundError(e.getMessage() + "  (suppress with -D" + SUPPRESS_PROPERTY_NAME + "=true)");
+                    if (e.getCause() != null) {
+                        newEx.initCause(e.getCause());
+                    }
+                    throw newEx;
+                }
+            }
+        }
+    };
+
+    /**
+     * 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}("jvmciServices")</tt>
+     */
+    @SuppressWarnings("unchecked")
+    public static <S> Iterable<S> load(Class<S> service) {
+        SecurityManager sm = System.getSecurityManager();
+        if (sm != null) {
+            sm.checkPermission(new RuntimePermission("jvmciServices"));
+        }
+        try {
+            return (Iterable<S>) cache.get(service);
+        } catch (UnsatisfiedLinkError e) {
+            return Collections.emptyList();
+        }
+    }
+
+    /**
+     * 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}("jvmciServices")</tt>
+     */
+    @SuppressWarnings({"unchecked"})
+    public static <S> S loadSingle(Class<S> service, boolean required) {
+        SecurityManager sm = System.getSecurityManager();
+        if (sm != null) {
+            sm.checkPermission(new RuntimePermission("jvmciServices"));
+        }
+        Iterable<S> providers;
+        try {
+            providers = (Iterable<S>) cache.get(service);
+        } catch (UnsatisfiedLinkError e) {
+            providers = Collections.emptyList();
+        }
+
+        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, "getServiceImpls");
+        Reflection.registerFieldsToFilter(Services.class, "cache");
+    }
+
+    private static native <S> S[] getServiceImpls(Class<?> service);
+}