code: package io.ray.runtime.util;
  
  import com.google.common.base.Preconditions;
  import java.io.File;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.RandomAccessFile;
  import java.nio.channels.FileLock;
  import java.nio.file.Files;
  import java.nio.file.Paths;
  import java.nio.file.StandardCopyOption;
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.lang3.SystemUtils;
  
  public class BinaryFileUtil {
  
    public static final String CORE_WORKER_JAVA_LIBRARY = "core_worker_library_java";
  
    /**
     * Extract a platform-native resource file to <code>destDir</code>. Note that this a process-safe
     * operation. If multi processes extract the file to same directory concurrently, this operation
     * will be protected by a file lock.
     *
     * @param destDir a directory to extract resource file to
     * @param fileName resource file name
     * @return extracted resource file
     */
    public static File getNativeFile(String destDir, String fileName) {
      final File dir = new File(destDir);
      if (!dir.exists()) {
        try {
          FileUtils.forceMkdir(dir);
        } catch (IOException e) {
          throw new RuntimeException("Couldn't make directory: " + dir.getAbsolutePath(), e);
        }
      }
      String lockFilePath = destDir + File.separator + "file_lock";
      try (FileLock ignored = new RandomAccessFile(lockFilePath, "rw").getChannel().lock()) {
        String resourceDir;
        if (SystemUtils.IS_OS_MAC) {
          resourceDir = "native/darwin/";
        } else if (SystemUtils.IS_OS_LINUX) {
          resourceDir = "native/linux/";
        } else {
          throw new UnsupportedOperationException("Unsupported os " + SystemUtils.OS_NAME);
        }
        /// File doesn't exist. Create a temp file and then rename it.
        final String tempFilePath = String.format("%s/%s.tmp", destDir, fileName);
        // Adding a temporary file here is used to fix the issue that when
        // a java worker crashes during extracting dynamic library file, next
        // java worker will use an incomplete file. The issue link is:
        //
        // https://github.com/ray-project/ray/issues/19341
        File tempFile = new File(tempFilePath);
  
        String resourcePath = resourceDir + fileName;
        File destFile = new File(String.format("%s/%s", destDir, fileName));
        if (destFile.exists()) {
          return destFile;
        }
  
        // File does not exist.
        try (InputStream is = BinaryFileUtil.class.getResourceAsStream("/" + resourcePath)) {
          Preconditions.checkNotNull(is, "{} doesn't exist.", resourcePath);
          Files.copy(is, Paths.get(tempFile.getCanonicalPath()), StandardCopyOption.REPLACE_EXISTING);
          if (!tempFile.renameTo(destFile)) {
            throw new RuntimeException(
                String.format(
                    "Couldn't rename temp file(%s) to %s",
                    tempFile.getAbsolutePath(), destFile.getAbsolutePath()));
          }
          return destFile;
        } catch (IOException e) {
          throw new RuntimeException("Couldn't get temp file from resource " + resourcePath, e);
        }
      } catch (IOException e) {
        throw new RuntimeException(e);
      }
    }
  }
  