public static int readPid(final File pidFile) {
    notNull(pidFile, "Invalid pidFile '" + pidFile + "' specified");
    isTrue(pidFile.exists(), "Nonexistent pidFile '" + pidFile + "' specified");

    try (BufferedReader reader = new BufferedReader(new FileReader(pidFile))) {
      return Integer.parseInt(reader.readLine());
    } catch (IOException e) {
      throw new UncheckedIOException(e);
    }
  }
Returns true if a process identified by the process id was running on this host machine and has
been terminated by this operation.

@param pid process id
@return true if the process was terminated by this operation
geode-core/src/main/java/org/apache/geode/internal/process/ProcessUtils.java