From: Tanaka Akira <akr@...>
Date: 2008-03-25T19:13:02+09:00
Subject: Re: Thread#raise, Thread#kill, and timeout.rb are unsafe

In article <b52213a47751467b7fcc5c5e245fdba4@localhost>,
  MenTaLguY <mental@rydia.net> writes:

> Now, the question with IO and asynchronous exceptions in Ruby is
> whether there is a good way to report a partial result?

I think defining the partial results causes, ultimately,
event driven architecture.

The partial result is similar to a continuation.

For syswrite, it is number of bytes wrote.  It can be used
to resume syswrite.

If IO#gets returns a partial result on an interrupt, it
should be usable to resume IO#gets.  It may contain the
bytes read.  If the IO converts character code, it may
contain characters converted, a state of character code
conversion engine and the bytes not converted yet.

If http request reading procedure returns partial result on
an interrupt, it should be usable to resume the procedure.
It contains a state of http request parser.  If the parser
is recursive decent, it contains the stack.  It is the
continuation.

So defining the partial result of a complex I/O operation
such as http request reading is translating continuation to
some data structure.  It is done by an event driven
architecture.

If a program is not event driven, I think that defining the
partial results for complex I/O operations is too tedious.
-- 
Tanaka Akira