[jvm-packages] JVM library loader extensions (#6630)

* [java] extending the library loader to use both OS and CPU architecture.

* Simplifying create_jni.py's architecture detection.

* Tidying up the architecture detection in create_jni.py

jvm-packages/create_jni.py

@@ -3,6 +3,7 @@ import errno
 import argparse
 import glob
 import os
+import platform
 import shutil
 import subprocess
 import sys
@@ -124,13 +125,23 @@ if __name__ == "__main__":
     xgboost4j_spark = 'xgboost4j-spark-gpu' if cli_args.use_cuda == 'ON' else 'xgboost4j-spark'
 
     print("copying native library")
-    library_name = {
+    library_name, os_folder = {
-        "win32": "xgboost4j.dll",
+        "Windows": ("xgboost4j.dll", "windows"),
-        "darwin": "libxgboost4j.dylib",
+        "Darwin": ("libxgboost4j.dylib", "macos"),
-        "linux": "libxgboost4j.so"
+        "Linux": ("libxgboost4j.so", "linux"),
-    }[sys.platform]
+        "SunOS": ("libxgboost4j.so", "solaris"),
-    maybe_makedirs("{}/src/main/resources/lib".format(xgboost4j))
+    }[platform.system()]
-    cp("../lib/" + library_name, "{}/src/main/resources/lib".format(xgboost4j))
+    arch_folder = {
+        "x86_64": "x86_64",  # on Linux & macOS x86_64
+        "amd64": "x86_64",  # on Windows x86_64
+        "i86pc": "x86_64",  # on Solaris x86_64
+        "sun4v": "sparc",  # on Solaris sparc
+        "arm64": "aarch64",  # on macOS & Windows ARM 64-bit
+        "aarch64": "aarch64"
+    }[platform.machine().lower()]
+    output_folder = "{}/src/main/resources/lib/{}/{}".format(xgboost4j, os_folder, arch_folder)
+    maybe_makedirs(output_folder)
+    cp("../lib/" + library_name, output_folder)
 
     print("copying pure-Python tracker")
     cp("../dmlc-core/tracker/dmlc_tracker/tracker.py",

jvm-packages/xgboost4j/src/main/java/ml/dmlc/xgboost4j/java/NativeLibLoader.java

@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2014 by Contributors
+ Copyright (c) 2014, 2021 by Contributors
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -15,8 +15,13 @@
  */
 package ml.dmlc.xgboost4j.java;
 
-import java.io.*;
+import java.io.File;
-import java.lang.reflect.Field;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.Locale;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -30,17 +35,19 @@ class NativeLibLoader {
   private static final Log logger = LogFactory.getLog(NativeLibLoader.class);
 
   private static boolean initialized = false;
-  private static final String nativeResourcePath = "/lib/";
+  private static final String nativeResourcePath = "/lib";
   private static final String[] libNames = new String[]{"xgboost4j"};
 
   static synchronized void initXGBoost() throws IOException {
     if (!initialized) {
+      String platform = computePlatformArchitecture();
       for (String libName : libNames) {
         try {
-          String libraryFromJar = nativeResourcePath + System.mapLibraryName(libName);
+          String libraryPathInJar = nativeResourcePath + "/" +
-          loadLibraryFromJar(libraryFromJar);
+              platform + "/" + System.mapLibraryName(libName);
+          loadLibraryFromJar(libraryPathInJar);
         } catch (IOException ioe) {
-          logger.error("failed to load " + libName + " library from jar");
+          logger.error("failed to load " + libName + " library from jar for platform " + platform);
           throw ioe;
         }
       }
@@ -48,6 +55,44 @@ class NativeLibLoader {
     }
   }
 
+  /**
+   * Computes a String representing the path to look for.
+   * Assumes the libraries are stored in the jar in os/architecture folders.
+   * <p>
+   * Throws IllegalStateException if the architecture or OS is unsupported.
+   * Supported OS: macOS, Windows, Linux, Solaris.
+   * Supported Architectures: x86_64, aarch64, sparc.
+   * @return The platform & architecture path.
+   */
+  private static String computePlatformArchitecture() {
+    String detectedOS;
+    String os = System.getProperty("os.name", "generic").toLowerCase(Locale.ENGLISH);
+    if (os.contains("mac") || os.contains("darwin")) {
+      detectedOS = "macos";
+    } else if (os.contains("win")) {
+      detectedOS = "windows";
+    } else if (os.contains("nux")) {
+      detectedOS = "linux";
+    } else if (os.contains("sunos")) {
+      detectedOS = "solaris";
+    } else {
+      throw new IllegalStateException("Unsupported os:" + os);
+    }
+    String detectedArch;
+    String arch = System.getProperty("os.arch", "generic").toLowerCase(Locale.ENGLISH);
+    if (arch.startsWith("amd64") || arch.startsWith("x86_64")) {
+      detectedArch = "x86_64";
+    } else if (arch.startsWith("aarch64") || arch.startsWith("arm64")) {
+      detectedArch = "aarch64";
+    } else if (arch.startsWith("sparc")) {
+      detectedArch = "sparc";
+    } else {
+      throw new IllegalStateException("Unsupported architecture:" + arch);
+    }
+
+    return detectedOS + "/" + detectedArch;
+  }
+
   /**
    * Loads library from current JAR archive
    * <p/>
@@ -65,9 +110,8 @@ class NativeLibLoader {
    * @throws IllegalArgumentException If the path is not absolute or if the filename is shorter than
    * three characters
    */
-  private static void loadLibraryFromJar(String path) throws IOException, IllegalArgumentException{
+  private static void loadLibraryFromJar(String path) throws IOException, IllegalArgumentException {
     String temp = createTempFileFromResource(path);
-    // Finally, load the library
     System.load(temp);
   }
 
@@ -82,8 +126,8 @@ class NativeLibLoader {
    * {@code path}.
    * @param path Path to the resources in the jar
    * @return The created temp file.
-   * @throws IOException
+   * @throws IOException If it failed to read the file.
-   * @throws IllegalArgumentException
+   * @throws IllegalArgumentException If the filename is invalid.
    */
   static String createTempFileFromResource(String path) throws
           IOException, IllegalArgumentException {
@@ -95,7 +139,7 @@ class NativeLibLoader {
     String[] parts = path.split("/");
     String filename = (parts.length > 1) ? parts[parts.length - 1] : null;
 
-    // Split filename to prexif and suffix (extension)
+    // Split filename to prefix and suffix (extension)
     String prefix = "";
     String suffix = null;
     if (filename != null) {
@@ -121,22 +165,18 @@ class NativeLibLoader {
     int readBytes;
 
     // Open and check input stream
-    InputStream is = NativeLibLoader.class.getResourceAsStream(path);
+    try (InputStream is = NativeLibLoader.class.getResourceAsStream(path);
-    if (is == null) {
+         OutputStream os = new FileOutputStream(temp)) {
-      throw new FileNotFoundException("File " + path + " was not found inside JAR.");
+      if (is == null) {
-    }
+        throw new FileNotFoundException("File " + path + " was not found inside JAR.");
+      }
 
-    // Open output stream and copy data between source file in JAR and the temporary file
+      // Open output stream and copy data between source file in JAR and the temporary file
-    OutputStream os = new FileOutputStream(temp);
-    try {
       while ((readBytes = is.read(buffer)) != -1) {
         os.write(buffer, 0, readBytes);
       }
-    } finally {
-      // If read/write fails, close streams safely before throwing an exception
-      os.close();
-      is.close();
     }
+
     return temp.getAbsolutePath();
   }