A system and method of providing edit and continue support in a software program debugging environment. It receives from one or more programs requests that it allocate memory from a dynamically allocable memory heap. Some embodiments include mechanical compression units. Each hard magnetic film extends toward the free layer in a vicinity of the spin valve film, such that as each hard magnetic film extends toward the spin valve film, a cross-sectional area thereof in a plane perpendicular to the layer width direction becomes progressively smaller.