Demonstrates that FileChannelImpl and FileChannel leak memory in j2objc, see https://github.com/google/j2objc/issues/603

NIOLeaks.java

import com.google.j2objc.annotations.AutoreleasePool;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.nio.channels.FileChannel;
import java.nio.channels.FileLock;

public class NIOLeaks {
  public static void main(String args[]) {
    for (int i = 0; ; i++) {
      foo(i);
      try {
        Thread.sleep(1000);
      } catch (Exception e) {
      }
    }
  }

  @AutoreleasePool
  public static void foo(int i) {
    try {
      File f = File.createTempFile("test", "tmp");
      System.out.println("Using temp: " + f);
      FileOutputStream fos = new FileOutputStream(f);
      FileChannel channel = fos.getChannel();
      FileLock lock = channel.lock();
      lock.close();
      channel.close();
      fos.close();
      f.delete();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }
}