| 摘要 |
One embodiment of the present invention provides a system that facilitates marking of objects defined within an object-oriented programming system to keep track of accesses to fields within the objects. The system operates by receiving a reference to a field within an object, and identifying a marking bit within the object that is associated with the field. Note that each marking bit within the object is associated with a different subset of fields within the object. Next, the system sets the marking bit to indicate that at least one field within the associated subset of fields has been referenced. Finally, the system performs the reference to the field. In one embodiment of the present invention, the object includes N marking bits numbered 0, 1, 2, . . . , N-1 and M fields numbered 0, 1, 2, . . . , M-1. In this embodiment, the system identifies the marking bit associated with the field by starting with a field number for the field, and applying a modulo N operation to the field number to produce a number for the associated marking bit. In a variation on this embodiment, N is a power of two.
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