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

   1 /* Copyright (c) 2014-2022. 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 block (thus executed when the class is loaded)
  18  * containing a call to this.
  19  */
  20 public final class NativeLib {
  21         private static final boolean WINDOWS_OS = System.getProperty("os.name").toLowerCase().startsWith("win");
  22         private static boolean isNativeInited = false;
  23         private 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 (WINDOWS_OS)
  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().contains("libcgraph.so"))
  73                                 System.err.println("HINT: Try to install the libcgraph package (sudo apt-get install libcgraph).");
  74                         else if (cause.getMessage().contains("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 for "+name+".");
  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                         final String tempPrefix = "simgrid-java-";
  94
  95                         if (WINDOWS_OS) {
  96                                 // The cleanup at exit fails on Windows where it is impossible to delete files which are still in
  97                                 // use.  Try to remove stale temporary files from previous executions, and limit disk usage.
  98                                 Path tmpdir = (new File(System.getProperty("java.io.tmpdir"))).toPath();
  99                                 try (Stream<Path> paths = Files.find(tmpdir, 1,
 100                                         (Path p, java.nio.file.attribute.BasicFileAttributes a) ->
 101                                                 a.isDirectory() && !p.equals(tmpdir) &&
 102                                                 p.getFileName().toString().startsWith(tempPrefix))) {
 103                                         paths.map(Path::toFile)
 104                                              .map(FileCleaner::new)
 105                                              .forEach(FileCleaner::run);
 106
 107                                 }
 108                         }
 109
 110                         tempDir = Files.createTempDirectory(tempPrefix);
 111                         // don't leak the files on disk, but remove it on JVM shutdown
 112                         Runtime.getRuntime().addShutdownHook(new Thread(new FileCleaner(tempDir.toFile())));
 113                 }
 114
 115                 /* For each possible filename of the given library on all possible OSes, try it */
 116                 for (String filename : new String[]
 117                    { name,
 118                      "lib"+name+".so",               /* linux */
 119                      name+".dll", "lib"+name+".dll", /* windows (pure and mingw) */
 120                      "lib"+name+".dylib"             /* macOS */}) {
 121
 122                         File fileOut = new File(tempDir.toFile(), filename);
 123                         try ( // Try-with-resources. These stream will be autoclosed when needed.
 124                                 InputStream in = NativeLib.class.getClassLoader().getResourceAsStream(path+filename);
 125                         ) {
 126                                 if (in != null) {
 127                                         /* copy the library in position */
 128                                         Files.copy(in, fileOut.toPath());
 129
 130                                         /* load that library */
 131                                         System.load(fileOut.getAbsolutePath());
 132
 133                                         /* It loaded! we're good */
 134                                         return true;
 135                                 }
 136                         }
 137                 }
 138
 139                 /* No suitable name found */
 140                 return false;
 141         }
 142
 143         /** Find where to search for the library in the jar -- keep it aligned with where cmake puts it! */
 144         private static String getPath() {
 145                 // Inspiration: https://github.com/xerial/snappy-java/blob/develop/src/main/java/org/xerial/snappy/OSInfo.java
 146                 String prefix = "NATIVE";
 147                 String os = System.getProperty("os.name");
 148                 String arch = System.getProperty("os.arch");
 149
 150                 if (arch.matches("^i[3-6]86$"))
 151                         arch = "x86";
 152                 else if ("x86_64".equalsIgnoreCase(arch) || "AMD64".equalsIgnoreCase(arch))
 153                         arch = "amd64";
 154
 155                 if (os.toLowerCase().startsWith("win")) {
 156                         os = "Windows";
 157                 } else if (os.contains("OS X")) {
 158                         os = "Darwin";
 159                 }
 160                 os = os.replace(' ', '_');
 161                 arch = arch.replace(' ', '_');
 162
 163                 return prefix + "/" + os + "/" + arch + "/";
 164         }
 165
 166         /** A hackish mechanism used to remove the file containing our library when the JVM shuts down */
 167         private static class FileCleaner implements Runnable {
 168                 private File dir;
 169                 public FileCleaner(File dir) {
 170                         this.dir = dir;
 171                 }
 172                 @Override
 173                 public void run() {
 174                         try (Stream<Path> paths = Files.walk(dir.toPath())) {
 175                                 paths.sorted(java.util.Comparator.reverseOrder())
 176                                      .map(java.nio.file.Path::toFile)
 177                                      //.peek(System.err::println) // Prints what gets removed
 178                                      .forEach(java.io.File::delete);
 179                         } catch(Exception e) {
 180                                 System.err.println("Error while cleaning temporary file " + dir.getAbsolutePath() +
 181                                                    ": " + e.getCause());
 182                                 e.printStackTrace();
 183                         }
 184                 }
 185         }
 186 }