ngx_http_upstream_upgraded_read_downstream   60 src/http/ngx_http_upstream.c static void ngx_http_upstream_upgraded_read_downstream(ngx_http_request_t *r);
ngx_http_upstream_upgraded_read_downstream 2981 src/http/ngx_http_upstream.c     r->read_event_handler = ngx_http_upstream_upgraded_read_downstream;