static Lock appendToFile_lock = lock();
sbool appendToFile_keepOpen;
static new HashMap<S, Writer> appendToFile_writers;

static void appendToFile(S path, S s) ctex {
  lock appendToFile_lock; // Let's just generally synchronize this to be safe.
  mkdirsForFile(new File(path));
  path = getCanonicalPath(path);
  Writer writer = appendToFile_writers.get(path);
  if (writer == null) {
    //print("[Logging to " + path + "]");
    writer = new BufferedWriter(new OutputStreamWriter(
      newFileOutputStream(path, true), "UTF-8"));
    if (appendToFile_keepOpen)
      appendToFile_writers.put(path, writer);
  }
  writer.write(s);
  if (!appendToFile_keepOpen)
    writer.close();
}
  
static void appendToFile(File path, String s) {
  if (path != null)
    appendToFile(path.getPath(), s);
}

svoid cleanMeUp_appendToFile {
  temp tempCleaningUp();
  lock appendToFile_lock;
  closeAllWriters(values(appendToFile_writers));
  appendToFile_writers.clear();
}