001/*
002 * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
003 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004 *
005 * This code is free software; you can redistribute it and/or modify it
006 * under the terms of the GNU General Public License version 2 only, as
007 * published by the Free Software Foundation.
008 *
009 * This code is distributed in the hope that it will be useful, but WITHOUT
010 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
011 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
012 * version 2 for more details (a copy is included in the LICENSE file that
013 * accompanied this code).
014 *
015 * You should have received a copy of the GNU General Public License version
016 * 2 along with this work; if not, write to the Free Software Foundation,
017 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
018 *
019 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
020 * or visit www.oracle.com if you need additional information or have any
021 * questions.
022 */
023package jdk.internal.jvmci.runtime;
024
025import java.util.*;
026
027public class JVMCI {
028
029    private static final JVMCIRuntime runtime;
030
031    private static native JVMCIRuntime initializeRuntime();
032
033    /**
034     * Gets the singleton {@link JVMCIRuntime} instance available to the application.
035     *
036     * @throws UnsupportedOperationException if JVMCI is not supported
037     */
038    public static JVMCIRuntime getRuntime() {
039        if (runtime == null) {
040            String javaHome = System.getProperty("java.home");
041            String vmName = System.getProperty("java.vm.name");
042            Formatter errorMessage = new Formatter();
043            errorMessage.format("The VM does not support the JVMCI API.%n");
044            errorMessage.format("Currently used Java home directory is %s.%n", javaHome);
045            errorMessage.format("Currently used VM configuration is: %s", vmName);
046            throw new UnsupportedOperationException(errorMessage.toString());
047        }
048        return runtime;
049    }
050
051    static {
052        JVMCIRuntime rt = null;
053        try {
054            rt = initializeRuntime();
055        } catch (UnsatisfiedLinkError e) {
056        }
057        runtime = rt;
058    }
059}