1 /* Copyright (c) 2014-2019. The SimGrid Team. All rights reserved. */
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. */
8 import java.io.FileOutputStream;
9 import java.io.InputStream;
10 import java.io.IOException;
11 import java.io.OutputStream;
13 import java.nio.file.Files;
14 import java.nio.file.Path;
15 import java.util.stream.Stream;
17 /** Helper class loading the native functions of SimGrid that we use for downcalls
19 * Almost all org.simgrid.msg.* classes contain a static bloc (thus executed when the class is loaded)
20 * containing a call to this.
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
26 /** A static-only "class" don't need no constructor */
28 throw new IllegalAccessError("Utility class");
31 /** Hidden debug main() function
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.
37 public static void main(String[] args) {
38 System.out.println("This jarfile searches the native code under: " +getPath());
41 /** Main function loading all the native classes that we need */
42 public static void nativeInit() {
46 if (System.getProperty("os.name").toLowerCase().startsWith("win"))
47 NativeLib.nativeInit("winpthread-1");
49 NativeLib.nativeInit("simgrid");
50 NativeLib.nativeInit("simgrid-java");
51 isNativeInited = true;
54 /** Helper function trying to load one requested library */
55 public static void nativeInit(String name) {
56 Throwable cause = null;
58 /* Prefer the version of the library bundled into the jar file and use it */
59 if (loadLibAsStream(name))
61 } catch (UnsatisfiedLinkError|SecurityException|IOException e) {
65 /* If not found, try to see if we can find a version on disk */
67 System.loadLibrary(name);
69 } catch (UnsatisfiedLinkError systemException) { /* don't care */ }
71 System.err.println("\nCannot load the bindings to the "+name+" library in path "+getPath()+" and no usable SimGrid installation found on disk.");
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).");
78 System.err.println("Try to install the missing dependencies, if any. Read carefully the following error message.");
81 cause.printStackTrace();
83 System.err.println("This jar file does not seem to fit your system, and no usable SimGrid installation found on disk for "+name+".");
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();
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())));
99 /* For each possible filename of the given library on all possible OSes, try it */
100 for (String filename : new String[]
102 "lib"+name+".so", /* linux */
103 name+".dll", "lib"+name+".dll", /* windows (pure and mingw) */
104 "lib"+name+".dylib" /* macOS */}) {
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);
113 /* copy the library in position */
114 byte[] buffer = new byte[4096];
116 while ((bytesRead = in.read(buffer)) != -1) // Read until EOF
117 out.write(buffer, 0, bytesRead);
122 /* load that library */
123 System.load(fileOut.getAbsolutePath());
125 /* It loaded! we're good */
130 /* No suitable name found */
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");
141 if (arch.matches("^i[3-6]86$"))
143 else if ("x86_64".equalsIgnoreCase(arch) || "AMD64".equalsIgnoreCase(arch))
146 if (os.toLowerCase().startsWith("win")) {
148 } else if (os.contains("OS X")) {
151 os = os.replace(' ', '_');
152 arch = arch.replace(' ', '_');
154 return prefix + "/" + os + "/" + arch + "/";
157 /** A hackish mechanism used to remove the file containing our library when the JVM shuts down */
158 private static class FileCleaner implements Runnable {
160 public FileCleaner(File dir) {
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());