Memory allocation techniques may provide improved security and performance. A method may comprise mapping a block of memory, dividing the block of memory into a plurality of heaps, dividing each heap into a plurality of sub-heaps, wherein each sub-heap is associated with one thread of software executing in the computer system, dividing each sub-heap into a plurality of bags, wherein each bag is associated with one size class of objects, creating an allocation buffer and a deallocation buffer for each bag, storing a plurality of objects in at least some of the bags, wherein each object is stored in a bag having size class corresponding to a size of the object, storing in the allocation buffer of each bag information relating to available objects stored in that bag, and storing in the deallocation buffer of each bag information relating to freed objects that were stored in that bag.