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.InputStream;
   9 import java.io.IOException;
  10 import java.io.File;
  11 import java.nio.file.Files;
  12 import java.nio.file.Path;
  13 import java.util.stream.Stream;
  14
  15 /** Helper class loading the native functions of SimGrid that we use for downcalls
  16  *
  17  * Almost all org.simgrid.msg.* classes contain a static bloc (thus executed when the class is loaded)
  18  * containing a call to this.
  19  */
  20 public final class NativeLib {
  21         private static boolean isNativeInited = false;
  22         private static Path tempDir = null; // where the embeeded libraries are unpacked before loading them
  23
  24         /** A static-only "class" don't need no constructor */
  25         private NativeLib() {
  26                 throw new IllegalAccessError("Utility class");
  27         }
  28
  29         /** Hidden debug main() function
  30          *
  31          * It is not the Main-Class defined in src/bindings/java/MANIFEST.in (org.simgrid.msg.Msg is),
  32          * so it won't get executed by default. But that's helpful to debug linkage errors, if you
  33          * know that it exists. It's used by cmake during the configure, to inform the user.
  34          */
  35         public static void main(String[] args) {
  36                 System.out.println("This jarfile searches the native code under: " +getPath());
  37         }
  38
  39         /** Main function loading all the native classes that we need */
  40         public static void nativeInit() {
  41                 if (isNativeInited)
  42                         return;
  43
  44                 if (System.getProperty("os.name").toLowerCase().startsWith("win"))
  45                         NativeLib.nativeInit("winpthread-1");
  46
  47                 NativeLib.nativeInit("simgrid");
  48                 NativeLib.nativeInit("simgrid-java");
  49                 isNativeInited = true;
  50         }
  51
  52         /** Helper function trying to load one requested library */
  53         public static void nativeInit(String name) {
  54                 Throwable cause = null;
  55                 try {
  56                         /* Prefer the version of the library bundled into the jar file and use it */
  57                         if (loadLibAsStream(name))
  58                                 return;
  59                 } catch (UnsatisfiedLinkError|SecurityException|IOException e) {
  60                         cause = e;
  61                 }
  62
  63                 /* If not found, try to see if we can find a version on disk */
  64                 try {
  65                         System.loadLibrary(name);
  66                         return;
  67                 } catch (UnsatisfiedLinkError systemException) { /* don't care */ }
  68
  69                 System.err.println("\nCannot load the bindings to the "+name+" library in path "+getPath()+" and no usable SimGrid installation found on disk.");
  70                 if (cause != null) {
  71                         if (cause.getMessage().contains("libcgraph.so"))
  72                                 System.err.println("HINT: Try to install the libcgraph package (sudo apt-get install libcgraph).");
  73                         else if (cause.getMessage().contains("libboost_context.so"))
  74                                 System.err.println("HINT: Try to install the boost-context package (sudo apt-get install libboost-context-dev).");
  75                         else
  76                                 System.err.println("Try to install the missing dependencies, if any. Read carefully the following error message.");
  77
  78                         System.err.println();
  79                         cause.printStackTrace();
  80                 } else {
  81                         System.err.println("This jar file does not seem to fit your system, and no usable SimGrid installation found on disk for "+name+".");
  82                 }
  83                 System.exit(1);
  84         }
  85
  86         /** Try to extract the library from the jarfile before loading it */
  87         private static boolean loadLibAsStream (String name) throws IOException, UnsatisfiedLinkError {
  88                 String path = NativeLib.getPath();
  89
  90                 // We must write the lib onto the disk before loading it -- stupid operating systems
  91                 if (tempDir == null) {
  92
  93                         if (System.getProperty("os.name").toLowerCase().startsWith("win")) {
  94                                 // The cleanup at exit fails on Windows where it is impossible to delete files which are still in
  95                                 // use.  Try to remove stale temporary files from previous executions, and limit disk usage.
  96                                 Path tmpdir = (new File(System.getProperty("java.io.tmpdir"))).toPath();
  97                                 try (Stream<Path> paths = Files.find(tmpdir, 1,
  98                                         (Path p, java.nio.file.attribute.BasicFileAttributes a) ->
  99                                                 a.isDirectory() && !p.equals(tmpdir) &&
 100                                                 p.getFileName().toString().startsWith("simgrid-java-"))) {
 101                                         paths.map(Path::toFile)
 102                                              .map(FileCleaner::new)
 103                                              .forEach(FileCleaner::run);
 104
 105                                 }
 106                         }
 107
 108                         tempDir = Files.createTempDirectory("simgrid-java-");
 109                         // don't leak the files on disk, but remove it on JVM shutdown
 110                         Runtime.getRuntime().addShutdownHook(new Thread(new FileCleaner(tempDir.toFile())));
 111                 }
 112
 113                 /* For each possible filename of the given library on all possible OSes, try it */
 114                 for (String filename : new String[]
 115                    { name,
 116                      "lib"+name+".so",               /* linux */
 117                      name+".dll", "lib"+name+".dll", /* windows (pure and mingw) */
 118                      "lib"+name+".dylib"             /* macOS */}) {
 119
 120                         File fileOut = new File(tempDir.toFile(), filename);
 121                         try ( // Try-with-resources. These stream will be autoclosed when needed.
 122                                 InputStream in = NativeLib.class.getClassLoader().getResourceAsStream(path+filename);
 123                         ) {
 124                                 if (in != null) {
 125                                         /* copy the library in position */
 126                                         Files.copy(in, fileOut.toPath());
 127
 128                                         /* load that library */
 129                                         System.load(fileOut.getAbsolutePath());
 130
 131                                         /* It loaded! we're good */
 132                                         return true;
 133                                 }
 134                         }
 135                 }
 136
 137                 /* No suitable name found */
 138                 return false;
 139         }
 140
 141         /** Find where to search for the library in the jar -- keep it aligned with where cmake puts it! */
 142         private static String getPath() {
 143                 // Inspiration: https://github.com/xerial/snappy-java/blob/develop/src/main/java/org/xerial/snappy/OSInfo.java
 144                 String prefix = "NATIVE";
 145                 String os = System.getProperty("os.name");
 146                 String arch = System.getProperty("os.arch");
 147
 148                 if (arch.matches("^i[3-6]86$"))
 149                         arch = "x86";
 150                 else if ("x86_64".equalsIgnoreCase(arch) || "AMD64".equalsIgnoreCase(arch))
 151                         arch = "amd64";
 152
 153                 if (os.toLowerCase().startsWith("win")) {
 154                         os = "Windows";
 155                 } else if (os.contains("OS X")) {
 156                         os = "Darwin";
 157                 }
 158                 os = os.replace(' ', '_');
 159                 arch = arch.replace(' ', '_');
 160
 161                 return prefix + "/" + os + "/" + arch + "/";
 162         }
 163
 164         /** A hackish mechanism used to remove the file containing our library when the JVM shuts down */
 165         private static class FileCleaner implements Runnable {
 166                 private File dir;
 167                 public FileCleaner(File dir) {
 168                         this.dir = dir;
 169                 }
 170                 @Override
 171                 public void run() {
 172                         try (Stream<Path> paths = Files.walk(dir.toPath())) {
 173                                 paths.sorted(java.util.Comparator.reverseOrder())
 174                                      .map(java.nio.file.Path::toFile)
 175                                      //.peek(System.err::println) // Prints what gets removed
 176                                      .forEach(java.io.File::delete);
 177                         } catch(Exception e) {
 178                                 System.err.println("Error while cleaning temporary file " + dir.getAbsolutePath() +
 179                                                    ": " + e.getCause());
 180                                 e.printStackTrace();
 181                         }
 182                 }
 183         }
 184 }