1 /*
   2  * Copyright (c) 2014, 2016, 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.lang.reflect.Method;
  26 import java.util.Map;
  27 
  28 /**
  29  * Provides utilities needed by JVMCI clients.
  30  *
  31  * This class must be compilable on JDK 8 and so use of API added in JDK 9 is made via reflection.
  32  */
  33 public final class Services {
  34 
  35     private Services() {
  36     }
  37 
  38     /**
  39      * Gets an unmodifiable copy of the system properties saved when {@link System} is initialized.
  40      */
  41     @SuppressWarnings("unchecked")
  42     public static Map<String, String> getSavedProperties() {
  43         SecurityManager sm = System.getSecurityManager();
  44         if (sm != null) {
  45             sm.checkPermission(new JVMCIPermission());
  46         }
  47         try {
  48             Class<?> vmClass = Class.forName("jdk.internal.misc.VM");
  49             Method m = vmClass.getMethod("getSavedProperties");
  50             return (Map<String, String>) m.invoke(null);
  51         } catch (Exception e) {
  52             throw new InternalError(e);
  53         }
  54     }
  55 
  56     /**
  57      * Causes the JVMCI subsystem to be initialized if it isn't already initialized.
  58      */
  59     public static void initializeJVMCI() {
  60         try {
  61             Class.forName("jdk.vm.ci.runtime.JVMCI");
  62         } catch (ClassNotFoundException e) {
  63             throw new InternalError(e);
  64         }
  65     }
  66 }