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Re: Dynamically growable/shrinkable block of RAM?

On Nov 2, 2003, at 4:43 AM, Theodore H. Smith wrote:

In essence, my question is: "Whats the most efficient way to dynamically shrink and grow a block of allocated RAM, using the least copy actions possible, while also allowing the area of RAM in shrunk blocks to be reused by other code".


The answer, on Mac OS X is vm_allocate/vm_deallocate.

So, right now, I'm using malloc/realloc, which in turn on OSX, is a wrapper to NewPtr and BlockMoveData. This wrapping is done by CodeWarrior's libraries (which of course the source to is included!)

So, thats MW ANSI malloc -> Carbon NewPtr -> Mach malloc -> Mach vm_allocate.

I would not recommend writing your own malloc replacement on top of vm_allocate; the Mach malloc is performs quite well. But if you have a special need for a super-high-performance page allocator, vm_allocate might be the way to go.

http://web.mit.edu/darwin/src/modules/xnu/osfmk/man/vm_allocate.html

--smz
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 >Dynamically growable/shrinkable block of RAM? (From: "Theodore H. Smith" <email@hidden>)



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