On 27 Jun 2012, at 02:19, Robert Dailey wrote:
On Mon, Jun 25, 2012 at 6:48 PM, Klaim - Joël Lamotte <mjklaim@gmail.com>wrote:
Hi,
don't look at the object_pool, look at pool. It provide only allocation and destruction methods, given a size at runtime. That way you can wrap it with a template function that give the size of the object you want to create to the pool for it to allocate memory for you.
Thanks for the response. I am reviewing the boost.pool reference here: http://www.boost.org/doc/libs/1_49_0/libs/pool/doc/html/boost/pool.html
Based on that, I do not see a way to allocate blocks of varying sizes. The documentation makes it sound like I have to set size_type to the largest object that will be allocated, which I have no reasonable way of knowing (I have hundreds of objects in my inheritance hierarchy, each with varying size, and no way to calculate the largest in a maintainable way).
The malloc() method does not take any parameters.
Am I misunderstanding you? Could you please point me in the right direction? Thanks again for your help.
Sorry for the late response, I've created a couple of code snippets that seem to do something like what I understand you're after. My first reaction on hearing your question was to create a distinct boost::object_pool instance for each class type. Whenever you construct an object of a given type, just use the pool for that object's construct method: https://gist.github.com/3004098 This strategy is straightforward, scalable, and can be integrated fairly readily with varying amounts of intrusiveness into the class hierarchy - but will require at least some level of coordination from the class authors or an exhaustive list of classes at some other point. Adding them to a namespace can be quite simple, and done in each class' .hpp file such that whenever you can construct an Example, you can call MyPools::Example.construct(); -- Secondly, and more directly along these lines of discussion; the pool_allocator (i.e. std::allocator) implementation provides: static pointer allocate(size_type n); … which could be used with placement new to wrap your construction however you liked without being intrusive into the constructed class. https://gist.github.com/3004102 -- Of course, I'm not handling the cleanup stage of this; which I expect is a very important consideration. I hope this helps :-) Regards, Rowan James