Re: [boost] lightweight_once (Was: Boost threadsafe singleton? - Inclusion in Boost)

From: Andrey Semashev (andysem_at_[hidden])
Date: 2007-08-27 13:53:05

Hello Gottlob,

>> > In this particular case the tool will be reviewed during the Boost.FSM
>> > review (if it will, since it's not for public use anyway), so
>> > including it in X-Files won't reduce the amount of reviews. On the
>> > other hand, if Boost.FSM is rejected but there is interest to this
>> > tool, I would gladly extract it to the X-Files project.
>>
>> If your library gets accepted, LWCO is accepted as an implementation
>> detail. AFAIK you need at least a fast-track review to make it a public
>> thing (not sure that's what you want, though).
>>

> I don't like the idea of important and *exposed* items being 'accepted
> as an implementation detail'.

> An init_once isn't an easy thing to write.  When people review
> Boost.FSM are they going to take a close look at the 'once'
> implementation.  Probably not.  They are going to focus on the central
> items related to the stated purpose of the library.

This lightweight_once is not a public component and is not a part of
Boost.FSM interface. No users will ever see it unless they dig into
the library implementation. And I had no intent to make it public
anyway - there is Boost.Thread implementation for that purpose. The
only reason why I implemented it is that I want my library to be
header-only. Therefore I don't see much sense in asking a separate
review for something that is an implementation detail of some another
library. The fact that I tried to make this detail general enough to
be able to be reused somewhere else (e.g. in another library) doesn't
mean that it is public.

>> However, I'd at least very much welcome a test suite for LWCO.

> Unless carefully reviewed, all threading code has bugs.  Even if
> tested.  It is the nature of threaded code.  It is *extremely* hard to
> test in such a way that all possible cases are tried.

Agreed.

-- 
Best regards,
 Andrey                            mailto:andysem_at_[hidden]