Universal constructions for large objects

We present lock-free and wait-free universal constructions for implementing large shared objects. Most previous universal constructions require proces ses to copy the entire object state. which is impractical for large objects . Previous attempts to address this problem require programmers to explicit ly fragment large objects into smaller, more manageable pieces, paying part icular attention to how such pieces are copied. in contrast, our constructi ons are designed to largely shield programmers from this fragmentation. Fur thermore, for many objects, our constructions result in lower copying overh ead than previous ones. Fragmentation is achieved in our constructions thro ugh the use of load-linked, store-conditional, and validate operations on a "large" multiword shared variable. Before presenting our constructions, we show how these operations can be efficiently implemented from similar one- word primitives.