accept_nonblock

        # OpenSSL::SSL::SSLSocket.accept_nonblock

(from ruby core)
### Implementation from SSLSocket
---
    ssl.accept_nonblock([options]) => self

---

Initiates the SSL/TLS handshake as a server in non-blocking manner.

    # emulates blocking accept
    begin
      ssl.accept_nonblock
    rescue IO::WaitReadable
      IO.select([s2])
      retry
    rescue IO::WaitWritable
      IO.select(nil, [s2])
      retry
    end

By specifying a keyword argument *exception* to `false`, you can
indicate that accept_nonblock should not raise an IO::WaitReadable or
IO::WaitWritable exception, but return the symbol `:wait_readable` or
`:wait_writable` instead.