FastCGI is designed to multiplex requests over a single connection, so ideally the server can open only one connection per worker to the FastCGI application and that's that. Doing this kind of multiplexing makes the code harder to follow and easier to break/leak etc on the gmid side however. OpenBSD' httpd seems to open one connection per client, so why can't we too? One connection per request is still way better (lighter) than using CGI, and we can avoid all the pitfalls of the multiplexing (keeping track of "live ids", properly shut down etc...)

We ended up copying too much data from the fastcgi process.

This is a big change in how gmid handles I/O. Initially we used a hand-written loop over poll(2), that then was evolved into something powered by libevent basic API. This meant that there were a lot of small "asynchronous" function that did one step, eventually scheduling the re-execution, that called each others in a chain. The new implementation revolves completely around libevent' bufferevents. It's more clear, as everything is implemented around the client_read and client_write functions. There is still space for improvements, like adding timeouts for one, but it's solid enough to be committed as is and then further improved.

add the reported request id if there's a mismatch and both the gai error and the errno value if getnameinfo fails.

This changes the fastcgi implementation from a blocking I/O to an async implementation on top of libevent' bufferevents. Should improve the responsiveness of gmid especially when using remote fastcgi applications.

we need to delete the events associated with the backends, otherwise the server process won't ever quit. Here, we add a pending counter to every backend and shut down immediately if they aren't handling any client; otherwise we try to close them as soon as possible (i.e. when they close the connection to the last connected client.)

Not production-ready yet, but it's a start. This adds a third ``backend'' for gmid: until now there it served local files or CGI scripts, now FastCGI applications too. FastCGI is meant to be an improvement over CGI: instead of exec'ing a script for every request, it allows to open a single connection to an ``application'' and send the requests/receive the responses over that socket using a simple binary protocol. At the moment gmid supports three different methods of opening a fastcgi connection: - local unix sockets, with: fastcgi "/path/to/sock" - network sockets, with: fastcgi tcp "host" [port] port defaults to 9000 and can be either a string or a number - subprocess, with: fastcgi spawn "/path/to/program" the fastcgi protocol is done over the executed program stdin of these, the last is only for testing and may be removed in the future. P.S.: the fastcgi rule is per-location of course :)