1 /*
   2  * Copyright (c) 1999, 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.  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 
  34 /**
  35  * Audio configuration class for exposing attributes specific to the platform or system.
  36  *
  37  * @author Kara Kytle
  38  * @author Florian Bomers
  39  */
  40 final class Platform {
  41 
  42 
  43     // STATIC FINAL CHARACTERISTICS
  44 
  45     // native library we need to load
  46     private static final String libNameMain     = "jsound";
  47     private static final String libNameALSA     = "jsoundalsa";
  48     private static final String libNameDSound   = "jsoundds";
  49 
  50     // extra libs handling: bit flags for each different library
  51     public static final int LIB_MAIN     = 1;
  52     public static final int LIB_ALSA     = 2;
  53     public static final int LIB_DSOUND   = 4;
  54 
  55     // bit field of the constants above. Willbe set in loadLibraries
  56     private static int loadedLibs = 0;
  57 
  58     // features: the main native library jsound reports which feature is
  59     // contained in which lib
  60     public static final int FEATURE_MIDIIO       = 1;
  61     public static final int FEATURE_PORTS        = 2;
  62     public static final int FEATURE_DIRECT_AUDIO = 3;
  63 
  64     // SYSTEM CHARACTERISTICS
  65     // vary according to hardware architecture
  66 
  67     // intel is little-endian.  sparc is big-endian.
  68     private static boolean bigEndian;
  69 
  70     static {
  71         if(Printer.trace)Printer.trace(">> Platform.java: static");
  72 
  73         loadLibraries();
  74         readProperties();
  75     }
  76 
  77 
  78     /**
  79      * Private constructor.
  80      */
  81     private Platform() {
  82     }
  83 
  84 
  85     // METHODS FOR INTERNAL IMPLEMENTATION USE
  86 
  87 
  88     /**
  89      * Dummy method for forcing initialization.
  90      */
  91     static void initialize() {
  92 
  93         if(Printer.trace)Printer.trace("Platform: initialize()");
  94     }
  95 
  96 
  97     /**
  98      * Determine whether the system is big-endian.
  99      */
 100     static boolean isBigEndian() {
 101 
 102         return bigEndian;
 103     }
 104 
 105 
 106     // PRIVATE METHODS
 107 
 108     /**
 109      * Load the native library or libraries.
 110      */
 111     private static void loadLibraries() {
 112         if(Printer.trace)Printer.trace(">>Platform.loadLibraries");
 113 
 114         // load the main library
 115         AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
 116             System.loadLibrary(libNameMain);
 117             return null;
 118         });
 119         // just for the heck of it...
 120         loadedLibs |= LIB_MAIN;
 121 
 122         // now try to load extra libs. They are defined at compile time in the Makefile
 123         // with the define EXTRA_SOUND_JNI_LIBS
 124         String extraLibs = nGetExtraLibraries();
 125         // the string is the libraries, separated by white space
 126         StringTokenizer st = new StringTokenizer(extraLibs);
 127         while (st.hasMoreTokens()) {
 128             final String lib = st.nextToken();
 129             try {
 130                 AccessController.doPrivileged((PrivilegedAction<Void>) () -> {
 131                     System.loadLibrary(lib);
 132                     return null;
 133                 });
 134 
 135                 if (lib.equals(libNameALSA)) {
 136                     loadedLibs |= LIB_ALSA;
 137                     if (Printer.debug) Printer.debug("Loaded ALSA lib successfully.");
 138                 } else if (lib.equals(libNameDSound)) {
 139                     loadedLibs |= LIB_DSOUND;
 140                     if (Printer.debug) Printer.debug("Loaded DirectSound lib successfully.");
 141                 } else {
 142                     if (Printer.err) Printer.err("Loaded unknown lib '"+lib+"' successfully.");
 143                 }
 144             } catch (Throwable t) {
 145                 if (Printer.err) Printer.err("Couldn't load library "+lib+": "+t.toString());
 146             }
 147         }
 148     }
 149 
 150 
 151     static boolean isMidiIOEnabled() {
 152         return isFeatureLibLoaded(FEATURE_MIDIIO);
 153     }
 154 
 155     static boolean isPortsEnabled() {
 156         return isFeatureLibLoaded(FEATURE_PORTS);
 157     }
 158 
 159     static boolean isDirectAudioEnabled() {
 160         return isFeatureLibLoaded(FEATURE_DIRECT_AUDIO);
 161     }
 162 
 163     private static boolean isFeatureLibLoaded(int feature) {
 164         if (Printer.debug) Printer.debug("Platform: Checking for feature "+feature+"...");
 165         int requiredLib = nGetLibraryForFeature(feature);
 166         boolean isLoaded = (requiredLib != 0) && ((loadedLibs & requiredLib) == requiredLib);
 167         if (Printer.debug) Printer.debug("          ...needs library "+requiredLib+". Result is loaded="+isLoaded);
 168         return isLoaded;
 169     }
 170 
 171     // the following native methods are implemented in Platform.c
 172     private native static boolean nIsBigEndian();
 173     private native static String nGetExtraLibraries();
 174     private native static int nGetLibraryForFeature(int feature);
 175 
 176     /**
 177      * Read the required system properties.
 178      */
 179     private static void readProperties() {
 180         // $$fb 2002-03-06: implement check for endianness in native. Facilitates porting !
 181         bigEndian = nIsBigEndian();
 182     }
 183 }