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From: Jeffrey Carter <jeffrey.carter@boeing.com>
Subject: Re: Complexity of protected objects
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Nick Roberts wrote:
> 
> On Mon, 25 Feb 2002 17:35:45 GMT, Jim Rogers
> <jimmaureenrogers@worldnet.att.net> strongly typed:
> 
> >Using a protected object to read and write files is a clear
> >violation of the intention and recommendations for proctected
> >objects. Protected objects should be non-blocking. I/O is
> >always potentially blocking.
> 
> It's perhaps a little sweeping to say "I/O is always potentially blocking".
> There may be certain rare cases where this is not so. But it will certainly
> always be so for reading or writing files, in practice.

ARM 9.5.1 says

Certain language-defined subprograms are potentially blocking. In
particular, the subprograms of the language-defined input-output
packages that manipulate files (implicitly or explicitly) are
potentially blocking.

Thus, I/O as always potentially blocking because the language defines it
as such.

-- 
Jeffrey Carter