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                 /* Don't leak the files on disk */
  53                 if (tempDir != null) {
  54                   FileCleaner fclean = new FileCleaner(tempDir.toFile());
  55                   fclean.run();
  56                 }
  57         }
  58
  59         /** Helper function trying to load one requested library */
  60         public static void nativeInit(String name) {
  61                 Throwable cause = null;
  62                 try {
  63                         /* Prefer the version of the library bundled into the jar file and use it */
  64                         if (loadLibAsStream(name))
  65                                 return;
  66                 } catch (UnsatisfiedLinkError|SecurityException|IOException e) {
  67                         cause = e;
  68                 }
  69
  70                 /* If not found, try to see if we can find a version on disk */
  71                 try {
  72                         System.loadLibrary(name);
  73                         return;
  74                 } catch (UnsatisfiedLinkError systemException) { /* don't care */ }
  75
  76                 System.err.println("\nCannot load the bindings to the "+name+" library in path "+getPath()+" and no usable SimGrid installation found on disk.");
  77                 if (cause != null) {
  78                         if (cause.getMessage().contains("libcgraph.so"))
  79                                 System.err.println("HINT: Try to install the libcgraph package (sudo apt-get install libcgraph).");
  80                         else if (cause.getMessage().contains("libboost_context.so"))
  81                                 System.err.println("HINT: Try to install the boost-context package (sudo apt-get install libboost-context-dev).");
  82                         else
  83                                 System.err.println("Try to install the missing dependencies, if any. Read carefully the following error message.");
  84
  85                         System.err.println();
  86                         cause.printStackTrace();
  87                 } else {
  88                         System.err.println("This jar file does not seem to fit your system, and no usable SimGrid installation found on disk for "+name+".");
  89                 }
  90                 System.exit(1);
  91         }
  92
  93         /** Try to extract the library from the jarfile before loading it */
  94         private static boolean loadLibAsStream (String name) throws IOException, UnsatisfiedLinkError {
  95                 String path = NativeLib.getPath();
  96
  97                 // We must write the lib onto the disk before loading it -- stupid operating systems
  98                 if (tempDir == null) {
  99                         final String tempPrefix = "simgrid-java-";
 100
 101                         if (WINDOWS_OS) {
 102                                 // The cleanup at exit fails on Windows where it is impossible to delete files which are still in
 103                                 // use.  Try to remove stale temporary files from previous executions, and limit disk usage.
 104                                 Path tmpdir = (new File(System.getProperty("java.io.tmpdir"))).toPath();
 105                                 try (Stream<Path> paths = Files.find(tmpdir, 1,
 106                                         (Path p, java.nio.file.attribute.BasicFileAttributes a) ->
 107                                                 a.isDirectory() && !p.equals(tmpdir) &&
 108                                                 p.getFileName().toString().startsWith(tempPrefix))) {
 109                                         paths.map(Path::toFile)
 110                                              .map(FileCleaner::new)
 111                                              .forEach(FileCleaner::run);
 112
 113                                 }
 114                         }
 115
 116                         tempDir = Files.createTempDirectory(tempPrefix);
 117                 }
 118
 119                 /* For each possible filename of the given library on all possible OSes, try it */
 120                 for (String filename : new String[]
 121                    { name,
 122                      "lib"+name+".so",               /* linux */
 123                      name+".dll", "lib"+name+".dll", /* windows (pure and mingw) */
 124                      "lib"+name+".dylib"             /* macOS */}) {
 125
 126                         File fileOut = new File(tempDir.toFile(), filename);
 127                         try ( // Try-with-resources. These stream will be autoclosed when needed.
 128                                 InputStream in = NativeLib.class.getClassLoader().getResourceAsStream(path+filename);
 129                         ) {
 130                                 if (in != null) {
 131                                         /* copy the library in position */
 132                                         Files.copy(in, fileOut.toPath());
 133
 134                                         /* load that library */
 135                                         System.load(fileOut.getAbsolutePath());
 136
 137                                         /* It loaded! we're good */
 138                                         return true;
 139                                 }
 140                         }
 141                 }
 142
 143                 /* No suitable name found */
 144                 return false;
 145         }
 146
 147         /** Find where to search for the library in the jar -- keep it aligned with where cmake puts it! */
 148         private static String getPath() {
 149                 // Inspiration: https://github.com/xerial/snappy-java/blob/develop/src/main/java/org/xerial/snappy/OSInfo.java
 150                 String prefix = "NATIVE";
 151                 String os = System.getProperty("os.name");
 152                 String arch = System.getProperty("os.arch");
 153
 154                 if (arch.matches("^i[3-6]86$"))
 155                         arch = "x86";
 156                 else if ("x86_64".equalsIgnoreCase(arch) || "AMD64".equalsIgnoreCase(arch))
 157                         arch = "amd64";
 158
 159                 if (os.toLowerCase().startsWith("win")) {
 160                         os = "Windows";
 161                 } else if (os.contains("OS X")) {
 162                         os = "Darwin";
 163                 }
 164                 os = os.replace(' ', '_');
 165                 arch = arch.replace(' ', '_');
 166
 167                 return prefix + "/" + os + "/" + arch + "/";
 168         }
 169
 170         /** A hackish mechanism used to remove the file containing our library when the JVM shuts down */
 171         private static class FileCleaner implements Runnable {
 172                 private File dir;
 173                 public FileCleaner(File dir) {
 174                         this.dir = dir;
 175                 }
 176                 @Override
 177                 public void run() {
 178                         try (Stream<Path> paths = Files.walk(dir.toPath())) {
 179                                 paths.sorted(java.util.Comparator.reverseOrder())
 180                                      .map(java.nio.file.Path::toFile)
 181                                      //.peek(System.err::println) // Prints what gets removed
 182                                      .forEach(java.io.File::delete);
 183                         } catch(Exception e) {
 184                                 System.err.println("Error while cleaning temporary file " + dir.getAbsolutePath() +
 185                                                    ": " + e.getCause());
 186                                 e.printStackTrace();
 187                         }
 188                 }
 189         }
 190 }