[Fwd: Refcounted allocator]

Assuming that this went to /dev/null...

-----Forwarded Message-----

> From: Robert Collins <robertc@squid-cache.org>
> To: Squid Dev <squid-dev@squid-cache.org>
> Subject: Refcounted allocator
> Date: 06 Nov 2002 18:18:04 +1100
>
> I've just commited a Reference counted template (with pointer semantics)
> to the refcount branch on devel's squid3 module.
>
> I haven't written the programmers guide doc's for this yet, so I'll note
> them here:
>
> To 'refcountise' a class, make it inherit from the Refcountable template
> class ie:
> ===
> class SomeClass :public RefCountable<SomeClass> {
> public:
> void deleteSelf() {delete this;}
> };
> ===
>
> You must define deleteSelf() as listed, because operator delete is
> static, and thus MemPools don't work nicely with delete unless we use a
> virtual method (which deleteSelf() is).
>
> Then, create a user typedef to act as the pointer:
> ===
> typedef RefCount<SomeClass> SomeClassPointer;
> ===
> Now, in user code, you simply pass around
> SomeClassPointer foo.
> To initialise a new heap/mempool allocated object:
> ===
> SomeClassPointer aPointer (new SomeClass);
> ===
> When aPointer goes out of scope, the references will be decremented, and
> when nothing references the object, it's deleteSelf() method will be
> called.
>
> Finally, we can only use this in classes that call the destructor at
> some point, to be sure that SomeClassPointer objects go out of scope.
> It's trival to make a cbdata class call the destructor, and I'll
> document that in an email to this list before commiting the refcount
> code to HEAD.. We can also convert cbdata classes to refcounted where
> appropriate (which may be everywhere, but that is a different
> discussion). It's also possible (as a transition strategy) to have
> CBDATA's SomeClassPointers, but that may not be needed so I won't code
> it up until it is :}).
>
> I'd like to bring this into HEAD very soon, so:
>
> Eugene, can you see if the test (in the test-suite) program passes for
> the refcounted template? I want to be sure it will work on your
> platform. Likewise, Guido, can you do the same?
>
> I'm going to try the sunos compiler on sourceforge now.... this worked fine.
>
> Rob
>
>
>