| 摘要 |
A computer system is described, having memory cells organized in a directed graph structure by means of pointers. Each cell has a reference count, and each pointer has a weight value. If a new pointer to a cell is created by copying an existing pointer, the new and existing pointers are given weights whose sum equals the old value of the existing pointer. In this way, the sum of the weights of the pointers to any cell are maintained equal to its reference count. If a pointer is destroyed, the reference count of the cell to which it points is reduced by the weight of the pointer. Thus, when the reference count of a cell reaches zero, it is safe to assume that there are no more existing pointers to it, and hence that cell my be reclaimed (garbage-collected) for re-use. |
