Re: pipe-filter self-tests

[Paolo Bonzini]

> Btw, what's the difference between pipe-filter-gi and pipe-filter-ii?
> Maybe the description field should clarify this?

One uses callbacks for both writes and reads.  The interface is very
symmetric, and it is basically a wrapper for a select(2) loop (or the
equivalent under Windows).

The other uses callbacks only for reads, and a regular write(2)-like
interface for writes, and it is useful for example if you have a complex
control flow to produce the input to the filter, but:

1) what you do with the output is easy (e.g. you may simply want to
write it to the console);

2) on the other hand, you do not know when the output will come, so you
need to be careful in order to avoid deadlocks.

Again, both Windows and POSIX systems are supported.