Mercurial > hg > truffle
diff graal/com.oracle.jvmci.service/src/com/oracle/jvmci/service/Services.java @ 21604:93f282187d90
moved JVMCI service API into separate com.oracle.jvmci.service module (JBS:GRAAL-53)
author | Doug Simon <doug.simon@oracle.com> |
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date | Fri, 29 May 2015 17:01:57 +0200 |
parents | graal/com.oracle.jvmci.runtime/src/com/oracle/jvmci/runtime/Services.java@d563baeca9df |
children | 71b338926f2e |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graal/com.oracle.jvmci.service/src/com/oracle/jvmci/service/Services.java Fri May 29 17:01:57 2015 +0200 @@ -0,0 +1,65 @@ +/* + * 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 static java.lang.String.*; + +import java.util.*; + +/** + * A mechanism on top of the standard {@link ServiceLoader} that enables a runtime to efficiently + * load services marked by {@link Service}. This may be important for services loaded early in the + * runtime initialization process. + */ +public class Services { + + private static final ClassValue<List<Service>> cache = new ClassValue<List<Service>>() { + @Override + protected List<Service> computeValue(Class<?> type) { + Service[] names = getServiceImpls(type); + if (names == null || names.length == 0) { + throw new InternalError( + format("No implementations for %s found (ensure %s extends %s and that in suite.py the \"annotationProcessors\" attribute for the project enclosing %s includes \"com.oracle.jvmci.service.processor\")", + type.getSimpleName(), type.getSimpleName(), Service.class, type.getSimpleName())); + } + return Arrays.asList(names); + } + }; + + /** + * Gets an {@link Iterable} of the implementations available for a given service. + */ + @SuppressWarnings("unchecked") + public static <S> Iterable<S> load(Class<S> service) { + if (Service.class.isAssignableFrom(service)) { + try { + return (Iterable<S>) cache.get(service); + } catch (UnsatisfiedLinkError e) { + // Fall back to standard SerivceLoader + } + } + return ServiceLoader.load(service, Services.class.getClassLoader()); + } + + private static native <S> S[] getServiceImpls(Class<?> service); +}