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comparison jvmci/jdk.vm.ci.services/src/jdk/vm/ci/services/JVMCIServiceLocator.java @ 23785:5cf445d2acf6 jvmci-0.22

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Exported elements referring to inaccessible types in jdk.vm.ci (JDK-8167180)
author Doug Simon <doug.simon@oracle.com>
date Tue, 11 Oct 2016 22:13:23 +0200
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23784:19222d463306 23785:5cf445d2acf6
1 /*
2 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23 package jdk.vm.ci.services;
24
25 import java.util.ArrayList;
26 import java.util.List;
27
28 /**
29 * Service-provider class for the runtime to locate providers of JVMCI services where the latter are
30 * not in packages exported by the JVMCI module. As part of instantiating
31 * {@link JVMCIServiceLocator}, all JVMCI packages will be {@linkplain Services#exportJVMCITo(Class)
32 * exported} to the module defining the class of the instantiated object.
33 *
34 * While the {@link #getProvider(Class)} method can be used directly, it's usually easier to use
35 * {@link #getProviders(Class)}.
36 */
37 public abstract class JVMCIServiceLocator {
38
39 private static Void checkPermission() {
40 SecurityManager sm = System.getSecurityManager();
41 if (sm != null) {
42 sm.checkPermission(new JVMCIPermission());
43 }
44 return null;
45 }
46
47 @SuppressWarnings("unused")
48 private JVMCIServiceLocator(Void ignore) {
49 }
50
51 /**
52 * Creates a capability for accessing JVMCI. Once successfully instantiated, JVMCI exports all
53 * its packages to the module defining the type of this object.
54 *
55 * @throws SecurityException if a security manager has been installed and it denies
56 * {@link JVMCIPermission}
57 */
58 protected JVMCIServiceLocator() {
59 this(checkPermission());
60 Services.exportJVMCITo(getClass());
61 }
62
63 /**
64 * Gets the provider of the service defined by {@code service} or {@code null} if this object
65 * does not have a provider for {@code service}.
66 */
67 public abstract <S> S getProvider(Class<S> service);
68
69 /**
70 * Gets the providers of the service defined by {@code service} by querying the
71 * {@link JVMCIServiceLocator} providers obtained by {@link Services#load(Class)}.
72 */
73 public static <S> List<S> getProviders(Class<S> service) {
74 List<S> providers = new ArrayList<>();
75 for (JVMCIServiceLocator access : Services.load(JVMCIServiceLocator.class)) {
76 S provider = access.getProvider(service);
77 if (provider != null) {
78 providers.add(provider);
79 }
80 }
81 return providers;
82 }
83 }