Merge "macOS build fix: no SOCK_CLOEXEC on darwin." am: 8fbb0d8d

    return nullptr;

  }

#if defined(__APPLE__)

  ctx->control_socket_.reset(socket(AF_UNIX, SOCK_SEQPACKET, 0));

  // TODO: find a better home for all these copies of the mac CLOEXEC workaround.

  if (int fd = ctx->control_socket_.get(), flags = fcntl(fd, F_GETFD);

      flags != -1 && (flags & FD_CLOEXEC) == 0) {

    fcntl(fd, F_SETFD, flags | FD_CLOEXEC);

  }

#else

  ctx->control_socket_.reset(socket(AF_UNIX, SOCK_SEQPACKET | SOCK_CLOEXEC, 0));

#endif

  if (ctx->control_socket_ < 0) {

    PLOG(ERROR) << "failed to create Unix domain socket";

    return nullptr;