I've wanted to look into this for quite awhile but never seem to have the time to do it...
Wouldn't it be cool if the interface between the server and mod_cgi (or any other content generator) could be configured to be full duplex (rather than stuck at half duplex as it is today)? With any version of Apache, it is not possible to support an HTTP transaction that consists of a continuous stream of chunked encoded bytes from the client and a concurrent stream of chunk encoded bytes back to the server because the interface between the server and the application (a cgi script for example) is half-duplex. The server will not attempt to read any bytes from the application until it has received ALL of the request. The cgi must read and buffer ALL of the request before sending any of the response else the application risks deadlocking with the server. This is an interesting exercise in that we will need manipulate the blocking behaviour of the network layer from the top of the filter stack. Bill