// will wait to see the Request's Body.Write result after getting a
// response from the server. See comments in (*persistConn).wroteRequest.
//
// In tests, we set this to a large value to avoid flakiness from inconsistent
// recycling of connections.
var maxWriteWaitBeforeConnReuse = 50 * time.Millisecond

// wroteRequest is a check before recycling a connection that the previous write
// (from writeLoop above) happened and was successful.

func (r *Request) write(w io.Writer, usingProxy bool, extraHeaders Header, waitForContinue func() bool) (err error) {
	trace := httptrace.ContextClientTrace(r.Context())
	if trace != nil && trace.WroteRequest != nil {
		defer func() {
			trace.WroteRequest(httptrace.WroteRequestInfo{
				Err: err,
			})
		}()
	}
	closed := false
	defer func() {
		if closed {
			return
		}