tcp.bind and tcp.listen always failed if settimeout(0).

[jakitliang]

As known to all. int bind(...) is an immediately completion function.

int bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen);

bind is not an async function but luasocket stupidly make it async

But luasocket needs set timeout(n) n > 0 to finish a simple bind.

Why do a bind need so much seconds?

And also tcp.listen is also an immediately completion function:

int listen(int sockfd, int backlog);

You just:

if (listen(&fd, 100) == -1)

to check the result immediately.

What does luasocket timeout for?

I GUESS the reason why luasocket is always failed coz using a stupid Thread way to do a dead easy bind:

void socked_bind() {
  auto ret = std::thread([]{
     return bind(fd, ...);
  })

  return ret
}

So the Lua side set timeout(0) means not to wait this thread and use the ret as result. And not doing Thread.join(ret).

So the bind procedure is released and failed.