fre 2008-01-18 klockan 16:17 -0500 skrev Akins, Brian:

In the end you need a bit of mixture between the models to work out. threads or even processes for complex processing or libraries outside your control, and async for the basic core to keep it lightweight in resources/request/connection.

There is quite a bit of research in programming models supporting mixed async/threaded/tasklet scheduling without forcing the programmer to know all details. Quite interesting reading if you haven't read those papers yet.

For example the tame approach (C++ preprocessor using libasync) used by OKWS and it's related cousin tamer (more lightweight library) is quite fun to work with, at least in theory.

Regarding CPU performance then you need a more complex workload than pure sendfile() shuffling of data to see much of a difference between threaded or async models. Especially if you look at smaller requests where the two almost diverge to the same model.. (N threads doing fast successive batch processing one request at a time with no wait time, or a event loop doing pretty much the same batching..).

Regards Henrik