src/bindings/java/org/simgrid/NativeLib.java

   1 /* Copyright (c) 2014-2016. The SimGrid Team. All rights reserved.          */
   2
   3 /* This program is free software; you can redistribute it and/or modify it
   4  * under the terms of the license (GNU LGPL) which comes with this package. */
   5
   6 package org.simgrid;
   7
   8 import java.io.FileOutputStream;
   9 import java.io.InputStream;
  10 import java.io.IOException;
  11 import java.io.OutputStream;
  12 import java.io.File;
  13 import java.nio.file.Files;
  14 import java.nio.file.Path;
  15
  16 /** Helper class loading the native functions of SimGrid that we use for downcalls
  17  *
  18  * Almost all org.simgrid.msg.* classes contain a static bloc (thus executed when the class is loaded)
  19  * containing a call to this.
  20  */
  21 public final class NativeLib {
  22         private static boolean isNativeInited = false;
  23         static Path tempDir = null; // where the embeeded libraries are unpacked before loading them
  24
  25         /** A static-only "class" don't need no constructor */
  26         private NativeLib() {
  27                 throw new IllegalAccessError("Utility class");
  28         }
  29
  30         /** Hidden debug main() function
  31          *
  32          * It is not the Main-Class defined in src/bindings/java/MANIFEST.in (org.simgrid.msg.Msg is),
  33          * so it won't get executed by default. But that's helpful to debug linkage errors, if you
  34          * know that it exists. It's used by cmake during the configure, to inform the user.
  35          */
  36         public static void main(String[] args) {
  37                 System.out.println("This jarfile searches the native code under: " +getPath());
  38         }
  39
  40         /** Main function loading all the native classes that we need */
  41         public static void nativeInit() {
  42                 if (isNativeInited)
  43                         return;
  44
  45                 if (System.getProperty("os.name").toLowerCase().startsWith("win"))
  46                         NativeLib.nativeInit("winpthread-1");
  47
  48                 NativeLib.nativeInit("simgrid");
  49                 NativeLib.nativeInit("simgrid-java");
  50                 isNativeInited = true;
  51         }
  52
  53         /** Helper function trying to load one requested library */
  54         public static void nativeInit(String name) {
  55                 Throwable cause = null;
  56                 try {
  57                         /* Prefer the version of the library bundled into the jar file and use it */
  58                         if (loadLibAsStream(name))
  59                                 return;
  60                 } catch (UnsatisfiedLinkError|SecurityException|IOException e) {
  61                         cause = e;
  62                 }
  63
  64                 /* If not found, try to see if we can find a version on disk */
  65                 try {
  66                         System.loadLibrary(name);
  67                         return;
  68                 } catch (UnsatisfiedLinkError systemException) { /* don't care */ }
  69
  70                 System.err.println("\nCannot load the bindings to the "+name+" library in path "+getPath()+" and no usable SimGrid installation found on disk.");
  71                 if (cause != null) {
  72                         if (cause.getMessage().matches(".*libcgraph.so.*"))
  73                                 System.err.println("HINT: Try to install the libcgraph package (sudo apt-get install libcgraph).");
  74                         else if (cause.getMessage().matches(".*libboost_context.so.*"))
  75                                 System.err.println("HINT: Try to install the boost-context package (sudo apt-get install libboost-context-dev).");
  76                         else
  77                                 System.err.println("Try to install the missing dependencies, if any. Read carefully the following error message.");
  78
  79                         System.err.println();
  80                         cause.printStackTrace();
  81                 } else {
  82                         System.err.println("This jar file does not seem to fit your system, and no usable SimGrid installation found on disk.");
  83                 }
  84                 System.exit(1);
  85         }
  86
  87         /** Try to extract the library from the jarfile before loading it */
  88         private static boolean loadLibAsStream (String name) throws IOException, UnsatisfiedLinkError {
  89                 String path = NativeLib.getPath();
  90
  91                 // We must write the lib onto the disk before loading it -- stupid operating systems
  92                 if (tempDir == null) {
  93                         tempDir = Files.createTempDirectory("simgrid-java-");
  94                         // don't leak the files on disk, but remove it on JVM shutdown
  95                         Runtime.getRuntime().addShutdownHook(new Thread(new FileCleaner(tempDir.toFile())));
  96                 }
  97
  98                 /* For each possible filename of the given library on all possible OSes, try it */
  99                 for (String filename : new String[]
 100                    { name,
 101                      "lib"+name+".so",               /* linux */
 102                      name+".dll", "lib"+name+".dll", /* windows (pure and mingw) */
 103                      "lib"+name+".dylib"             /* mac osx */}) {
 104
 105                         File fileOut = new File(tempDir.toFile().getAbsolutePath() + File.separator + filename);
 106                         try ( // Try-with-resources. These stream will be autoclosed when needed.
 107                                 InputStream in = NativeLib.class.getClassLoader().getResourceAsStream(path+filename);
 108                                 OutputStream out = new FileOutputStream(fileOut);
 109                         ) {
 110                                 if (in == null)
 111                                         continue; // Try the next name: no such file found
 112
 113                                 /* copy the library in position */
 114                                 byte[] buffer = new byte[4096];
 115                                 int bytesRead;
 116                                 while ((bytesRead = in.read(buffer)) != -1)     // Read until EOF
 117                                         out.write(buffer, 0, bytesRead);
 118
 119                                 /* load that shit */
 120                                 System.load(fileOut.getAbsolutePath());
 121
 122                                 /* It loaded! we're good */
 123                                 return true;
 124
 125                         }
 126                 }
 127
 128                 /* No suitable name found */
 129                 return false;
 130         }
 131
 132         /** Find where to search for the library in the jar -- keep it aligned with where cmake puts it! */
 133         private static String getPath() {
 134                 // Inspiration: https://github.com/xerial/snappy-java/blob/develop/src/main/java/org/xerial/snappy/OSInfo.java
 135                 String prefix = "NATIVE";
 136                 String os = System.getProperty("os.name");
 137                 String arch = System.getProperty("os.arch");
 138
 139                 if (arch.matches("^i[3-6]86$"))
 140                         arch = "x86";
 141                 else if ("x86_64".equalsIgnoreCase(arch) || "AMD64".equalsIgnoreCase(arch))
 142                         arch = "amd64";
 143
 144                 if (os.toLowerCase().startsWith("win")){
 145                         os = "Windows";
 146                 } else if (os.contains("OS X"))
 147                         os = "Darwin";
 148
 149                 os = os.replace(' ', '_');
 150                 arch = arch.replace(' ', '_');
 151
 152                 return prefix + "/" + os + "/" + arch + "/";
 153         }
 154
 155         /** A hackish mechanism used to remove the file containing our library when the JVM shuts down */
 156         private static class FileCleaner implements Runnable {
 157                 private File dir;
 158                 public FileCleaner(File dir) {
 159                         this.dir = dir;
 160                 }
 161                 @Override
 162                 public void run() {
 163                         try {
 164                                 for (File f : dir.listFiles())
 165                                         if (! f.delete() )
 166                                                 System.err.println("Unable to clean temporary file "+f.getAbsolutePath()+" during shutdown.");
 167                                 if (! dir.delete() )
 168                                         System.err.println("Unable to clean temporary file "+dir.getAbsolutePath()+" during shutdown.");
 169                         } catch(Exception e) {
 170                                 System.err.println("Unable to clean temporary file "+dir.getAbsolutePath()+" during shutdown: "+e.getCause());
 171                                 e.printStackTrace();
 172                         }
 173                 }
 174         }
 175 }