Gets the non-blocking mode of the descriptor.
bool non_blocking() const;
true
if the descriptor's synchronous operations will fail
with asio::error::would_block
if they are unable to perform
the requested operation immediately. If false
, synchronous
operations will block until complete.
The non-blocking mode has no effect on the behaviour of asynchronous
operations. Asynchronous operations will never fail with the error asio::error::would_block
.