A better place to ask this kind of question is golang-nuts. See https://golang.org/wiki/Questions.

@julieqiu I think you are missing my point. I'm not asking about the answer. I have the answer already, and even in the [stackoverflow]https://stackoverflow.com/questions/57246852 it's also answered.

But the things it the answer is not documented in any golang doc. This might cause some confusion.

The net/http server checks for closed connections by reading the connection. No reads are started until the application starts reading the request body (if any).

What I mean is above statement. I think it's need to be documented.

On GET client request, when the request is cancelled from the client side then immediately r.Context().Done() channel receives a value. But on POST request, it does not.

On POST client request, the r.Context().Done() never receive any value, unless in the handler there is a read process from r.Body and during that reading process the request is cancelled by the client. Then only that the the channel will receive a value.

@novalgung sorry for the confusion. It seems like this is the correct behavior,
but perhaps someone with net/http expertise should decide if this needs to be
documented.

/cc @dmitshur @bradfitz