source: branches/ithildin-1.1/doc/heaps.txt @ 490

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# heaps.txt: documentation of the blockheap allocator.
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# Copyright 2002 the Ithildin Project.
# See the COPYING file for more information on licensing and use.
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# $Id$
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A simple description of the heap-allocation system:

The heap allocator is a simple mechanism to prevent the cycle of malloc/free
which often occurs when allocating items of the same size.  With a heap
allocator, several items are allocated at once, and instead of returning the
memory to the system, the memory is instead simply kept to be re-allocated
later.  The system assumes that a lot of allocation and de-allocation will
occur at once.

The system uses a small/simple singly linked list within each heap to
specify free memory.  The list takes up no additional memory, because the
pointers are simply placed at the beginning of a free block in the heap,
using the memory already allocated.  The list head does, of course, takes
memory.  For more gory details, check out the actual code.