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

   1 /* Copyright (c) 2014-2019. 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 import java.util.stream.Stream;
  16
  17 /** Helper class loading the native functions of SimGrid that we use for downcalls
  18  *
  19  * Almost all org.simgrid.msg.* classes contain a static bloc (thus executed when the class is loaded)
  20  * containing a call to this.
  21  */
  22 public final class NativeLib {
  23         private static boolean isNativeInited = false;
  24         private static Path tempDir = null; // where the embeeded libraries are unpacked before loading them
  25
  26         /** A static-only "class" don't need no constructor */
  27         private NativeLib() {
  28                 throw new IllegalAccessError("Utility class");
  29         }
  30
  31         /** Hidden debug main() function
  32          *
  33          * It is not the Main-Class defined in src/bindings/java/MANIFEST.in (org.simgrid.msg.Msg is),
  34          * so it won't get executed by default. But that's helpful to debug linkage errors, if you
  35          * know that it exists. It's used by cmake during the configure, to inform the user.
  36          */
  37         public static void main(String[] args) {
  38                 System.out.println("This jarfile searches the native code under: " +getPath());
  39         }
  40
  41         /** Main function loading all the native classes that we need */
  42         public static void nativeInit() {
  43                 if (isNativeInited)
  44                         return;
  45
  46                 if (System.getProperty("os.name").toLowerCase().startsWith("win"))
  47                         NativeLib.nativeInit("winpthread-1");
  48
  49                 NativeLib.nativeInit("simgrid");
  50                 NativeLib.nativeInit("simgrid-java");
  51                 isNativeInited = true;
  52         }
  53
  54         /** Helper function trying to load one requested library */
  55         public static void nativeInit(String name) {
  56                 Throwable cause = null;
  57                 try {
  58                         /* Prefer the version of the library bundled into the jar file and use it */
  59                         if (loadLibAsStream(name))
  60                                 return;
  61                 } catch (UnsatisfiedLinkError|SecurityException|IOException e) {
  62                         cause = e;
  63                 }
  64
  65                 /* If not found, try to see if we can find a version on disk */
  66                 try {
  67                         System.loadLibrary(name);
  68                         return;
  69                 } catch (UnsatisfiedLinkError systemException) { /* don't care */ }
  70
  71                 System.err.println("\nCannot load the bindings to the "+name+" library in path "+getPath()+" and no usable SimGrid installation found on disk.");
  72                 if (cause != null) {
  73                         if (cause.getMessage().contains("libcgraph.so"))
  74                                 System.err.println("HINT: Try to install the libcgraph package (sudo apt-get install libcgraph).");
  75                         else if (cause.getMessage().contains("libboost_context.so"))
  76                                 System.err.println("HINT: Try to install the boost-context package (sudo apt-get install libboost-context-dev).");
  77                         else
  78                                 System.err.println("Try to install the missing dependencies, if any. Read carefully the following error message.");
  79
  80                         System.err.println();
  81                         cause.printStackTrace();
  82                 } else {
  83                         System.err.println("This jar file does not seem to fit your system, and no usable SimGrid installation found on disk for "+name+".");
  84                 }
  85                 System.exit(1);
  86         }
  87
  88         /** Try to extract the library from the jarfile before loading it */
  89         private static boolean loadLibAsStream (String name) throws IOException, UnsatisfiedLinkError {
  90                 String path = NativeLib.getPath();
  91
  92                 // We must write the lib onto the disk before loading it -- stupid operating systems
  93                 if (tempDir == null) {
  94                         tempDir = Files.createTempDirectory("simgrid-java-");
  95                         // don't leak the files on disk, but remove it on JVM shutdown
  96                         Runtime.getRuntime().addShutdownHook(new Thread(new FileCleaner(tempDir.toFile())));
  97                 }
  98
  99                 /* For each possible filename of the given library on all possible OSes, try it */
 100                 for (String filename : new String[]
 101                    { name,
 102                      "lib"+name+".so",               /* linux */
 103                      name+".dll", "lib"+name+".dll", /* windows (pure and mingw) */
 104                      "lib"+name+".dylib"             /* macOS */}) {
 105
 106                         File fileOut = new File(tempDir.toFile().getAbsolutePath() + File.separator + filename);
 107                         boolean done = false;
 108                         try ( // Try-with-resources. These stream will be autoclosed when needed.
 109                                 InputStream in = NativeLib.class.getClassLoader().getResourceAsStream(path+filename);
 110                                 OutputStream out = new FileOutputStream(fileOut);
 111                         ) {
 112                                 if (in != null) {
 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                                         done = true;
 119                                 }
 120                         }
 121                         if (done) {
 122                                 /* load that library */
 123                                 System.load(fileOut.getAbsolutePath());
 124
 125                                 /* It loaded! we're good */
 126                                 return true;
 127                         }
 128                 }
 129
 130                 /* No suitable name found */
 131                 return false;
 132         }
 133
 134         /** Find where to search for the library in the jar -- keep it aligned with where cmake puts it! */
 135         private static String getPath() {
 136                 // Inspiration: https://github.com/xerial/snappy-java/blob/develop/src/main/java/org/xerial/snappy/OSInfo.java
 137                 String prefix = "NATIVE";
 138                 String os = System.getProperty("os.name");
 139                 String arch = System.getProperty("os.arch");
 140
 141                 if (arch.matches("^i[3-6]86$"))
 142                         arch = "x86";
 143                 else if ("x86_64".equalsIgnoreCase(arch) || "AMD64".equalsIgnoreCase(arch))
 144                         arch = "amd64";
 145
 146                 if (os.toLowerCase().startsWith("win")) {
 147                         os = "Windows";
 148                 } else if (os.contains("OS X")) {
 149                         os = "Darwin";
 150                 }
 151                 os = os.replace(' ', '_');
 152                 arch = arch.replace(' ', '_');
 153
 154                 return prefix + "/" + os + "/" + arch + "/";
 155         }
 156
 157         /** A hackish mechanism used to remove the file containing our library when the JVM shuts down */
 158         private static class FileCleaner implements Runnable {
 159                 private File dir;
 160                 public FileCleaner(File dir) {
 161                         this.dir = dir;
 162                 }
 163                 @Override
 164                 public void run() {
 165                         try (Stream<Path> paths = Files.walk(dir.toPath())) {
 166                                 paths.sorted(java.util.Comparator.reverseOrder())
 167                                      .map(java.nio.file.Path::toFile)
 168                                      //.peek(System.out::println) // Prints what gets removed
 169                                      .forEach(java.io.File::delete);
 170                         } catch(Exception e) {
 171                                 System.out.println("Error while cleaning temporary file "+dir.getAbsolutePath()+" during shutdown: "+e.getCause());
 172                                 e.printStackTrace();
 173                         }
 174                 }
 175         }
 176 }