Policy-Based Memory Allocation
By Andrei Alexandrescu and Emery Berger, December 01, 2005
The way your application allocates memory can have a dramatic effect on its performance. Modern general-purpose memory allocators are pretty efficient, but there's always room for improvement.
December, 2005: Policy-Based Memory Allocation
Listing 3
template <class Super, size_t S1, size_t S2>
struct FLHeap {
~FLHeap() {
while (myFreeList) {
freeObject* next = myFreeList->next;
Super::free(myFreeList);
myFreeList = next;
}
}
void * malloc(const size_t s) {
if (s < S1 || s > S2)) {
return Super::malloc(s);
}
if (!myFreeList) {
return Super::malloc(S2);
}
void * ptr = myFreeList;
myFreeList = myFreeList->next;
return ptr;
}
void free(void * p) {
const size_t s = getSize(p);
if (s < S1 || s > S2) {
return Super::free(p);
}
freeObject p =
reinterpret_cast<freeObject *>(ptr);
p->next = myFreeList;
myFreeList = p;
}
private:
/// The linked list pointer we embed in the freed objects.
class freeObject {
public:
freeObject * next;
};
/// The head of the linked list of freed objects.
freeObject * myFreeList;
};
