Object resizing and reclamation through the use of hardware bit-maps

Abstract

The memory intensive nature of object-oriented languages such as C++ and Java has created the need of a high-performance dynamic memory management. Object-oriented applications often generate higher memory intensity in the heap region. Thus, high-performance memory manager is needed to cope with such applications. As today's VLSI technology advances, it becomes more and more attractive to map software algorithms such as malloc(), free(), realloc(), and garbage collection into hardware. This paper presents hardware designs of realloc function and sweeping function (for mark and sweep garbage collection) that fully utilize the advantages of combinational logic. In our scheme, the reallocation on the original block can be done in constant time. If the reallocation on the original block is not possible, the previously proposed malloc() and free() can be used to move the contents to a new location. For the sweeping function, the bit-sweeper can detect and sweep the garbage in constant time. Since the sweeping phase often consumes more time than the marking phase, the garbage collection time can be substantially improved. The hardware complexity of proposed scheme (i.e. X-Unit, RS-unit, ESG-unit, and bit-sweeper) is O( n), where n represents the size of bit-map.