rev 55657 : 8227587: Add internal privileged System.loadLibrary
Reviewed-by: rriggs

   1 /*
   2  * Copyright (c) 1999, 2019, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.media.sound;
  27 
  28 import java.security.AccessController;
  29 import java.security.PrivilegedAction;
  30 import java.util.StringTokenizer;
  31 
  32 /**
  33  * Audio configuration class for exposing attributes specific to the platform or system.
  34  *
  35  * @author Kara Kytle
  36  * @author Florian Bomers
  37  */
  38 final class Platform {
  39 
  40     // native library we need to load
  41     private static final String libName = "jsound";
  42 
  43     private static boolean isNativeLibLoaded;
  44 
  45     // SYSTEM CHARACTERISTICS
  46     // vary according to hardware architecture
  47 
  48     // intel is little-endian.  sparc is big-endian.
  49     private static boolean bigEndian;
  50 
  51     static {
  52         loadLibraries();
  53     }
  54 
  55     /**
  56      * Private constructor.
  57      */
  58     private Platform() {
  59     }
  60 
  61     /**
  62      * Dummy method for forcing initialization.
  63      */
  64     static void initialize() {
  65     }
  66 
  67     /**
  68      * Determine whether the system is big-endian.
  69      */
  70     static boolean isBigEndian() {
  71         return bigEndian;
  72     }
  73 
  74     /**
  75      * Load the native library or libraries.
  76      */
  77     private static void loadLibraries() {
  78         // load the native library
  79         isNativeLibLoaded = true;
  80         try {
  81             AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
  82                 System.loadLibrary(libName);
  83                 return null;
  84             });
  85         } catch (Throwable t) {
  86             if (Printer.err) Printer.err("Couldn't load library "+libName+": "+t.toString());
  87             isNativeLibLoaded = false;
  88         }
  89         if (isNativeLibLoaded) {
  90             bigEndian = nIsBigEndian();
  91         }
  92     }
  93 
  94     static boolean isMidiIOEnabled() {
  95         return isNativeLibLoaded;
  96     }
  97 
  98     static boolean isPortsEnabled() {
  99         return isNativeLibLoaded;
 100     }
 101 
 102     static boolean isDirectAudioEnabled() {
 103         return isNativeLibLoaded;
 104     }
 105 
 106     // the following native method is implemented in Platform.c
 107     private static native boolean nIsBigEndian();
 108 }
--- EOF ---