Method RunInChild

cpp/src/arrow/util/atfork_test.cc:88–101

#ifndef _WIN32
  void RunInChild(std::function<void()> func) {
    auto child_pid = fork();
    if (child_pid == -1) {
      ASSERT_OK(IOErrorFromErrno(errno, "Error calling fork(): "));
    }
    if (child_pid == 0) {
      // Child
      ASSERT_NO_FATAL_FAILURE(func()) << "Failure in child process";
      std::exit(0);
    } else {
      // Parent
      AssertChildExit(child_pid);
    }
  }
#endif

  std::mutex mutex_;