Method shutdown

src/posix/libevent/libevent_ssl_socket.cpp:160–218

Try<Nothing, SocketError> LibeventSSLSocketImpl::shutdown(int how)
{
  // Nothing to do if this socket was never initialized.
  synchronized (lock) {
    if (bev == nullptr) {
      // If it was not initialized, then there should also be no
      // requests.
      CHECK(connect_request.get() == nullptr);
      CHECK(recv_request.get() == nullptr);
      CHECK(send_request.get() == nullptr);

      // We expect this to fail and generate an 'ENOTCONN' failure as
      // no connection should exist at this point.
      if (::shutdown(s, how) < 0) {
        return SocketError();
      }

      return Nothing();
    }
  }

  // Extend the life-time of 'this' through the execution of the
  // lambda in the event loop. Note: The 'self' needs to be explicitly
  // captured because we're not using it in the body of the lambda. We
  // can use a 'shared_ptr' because run_in_event_loop is guaranteed to
  // execute.
  auto self = shared(this);

  run_in_event_loop(
      [self]() {
        CHECK(__in_event_loop__);
        CHECK(self);

        CHECK_NOTNULL(self->bev);

        synchronized (self->bev) {
          Owned<RecvRequest> request;

          // Swap the 'recv_request' under the object lock.
          synchronized (self->lock) {
            std::swap(request, self->recv_request);
          }

          // If there is still a pending receive request then close it.
          if (request.get() != nullptr) {
            request->promise
              .set(bufferevent_read(self->bev, request->data, request->size));
          }

          // Workaround for SSL shutdown, see http://www.wangafu.net/~nickm/libevent-book/Ref6a_advanced_bufferevents.html // NOLINT
          SSL* ssl = bufferevent_openssl_get_ssl(self->bev);
          SSL_set_shutdown(ssl, SSL_RECEIVED_SHUTDOWN);
          SSL_shutdown(ssl);
        }
      },
      DISALLOW_SHORT_CIRCUIT);

  return Nothing();