Method ChildAfterFork

cpp/src/arrow/util/cancel.cc:273–283

  void ParentAfterFork() { mutex_.unlock(); }

  void ChildAfterFork() {
    new (&mutex_) std::mutex;
    // Leak previous thread, as it has become invalid.
    // We can't spawn a new one here as it would have unfortunate side effects;
    // especially in the frequent context of a fork+exec.
    // (for example the Python subprocess module closes all fds before calling exec)
    ARROW_UNUSED(signal_receiving_thread_.release());
    // Make internal state consistent: with no listening thread, we shouldn't
    // feed the self-pipe from the signal handler.
    UnregisterHandlers();
  }

  std::mutex mutex_;
  std::vector<SavedSignalHandler> saved_handlers_;