Re: [boost] Threadsafe singleton - questions

From: Robert Ramey (ramey_at_[hidden])
Date: 2007-08-24 17:56:16

Robert Ramey wrote:
> I'm going through the documentation and now have some questions.
> I would hope that the documentation could be expanded to
> include answers to these questions.
>
> a) reference is made to a "lease" which sounds like a mutex
> to me.  But its not obvious to me how this should be used.
> How does the compare with the pattern that I am more
> familiar with
>
> class s : singlton
>      mutex m_mutex
> ...
>
> my_function(...){
>    scoped_lock(m_mutex);
>   ...
> }
>
> OK - I've looked again and I think its clear to me how this
> is to be used.
>
> We need a tutorial here !!!!
>
> b) reference is made to boost::restricted which I couldn't
> find anywhere.

c) the synopsis specifies

static unspecified instance;

But the Expression Symatics specifies D::instance->m which seems
inconsistent to me.  I Rather expect the synopsis to say

D:instance.m

or

D::get_instance().m

d) what about access to object which don't require thread locking - for 
example
const members.  Do they need locking/leasing also? I would guess not but?

e) What does D::instance return ? a reference or pointer to the single 
instance of D
or something else. I would expect the former, but the synopsis contains

static "unspecified" instance

rather than

static T instance as I would expect.

f) can "const" static objects be created?

g) what happens if same interface used by different DLLS.  Is one instance
still created?

Robert Ramey

Robert Ramey