Abortable and query-abortable objects and their efficient implementation
Marcos K. Aguilera, Svend Frølund, Vassos Hadzilacos, Stephanie Lorraine Horn, Sam Toueg · 2007
We introduce abortable and query-abortable objects, intended for asynchronous shared-memory systems with low contention. These objects behave like ordinary objects when accessed sequentially, but may abort operations when accessed concurrently. An aborted operation may or may not take effect, i.e., cause a state transition, and it returns no indication of which possibility occurred. Since this uncertainty is problematic, a query-abortable object supports a QUERY operation that each process can use to determine its last non-QUERY operation on the object that caused a state transition, and the response associated with this state transition. Query-abortable objects can easily implement obstruction-free objects (introduced by Herlihy, Luchangco and Moir) and pausable objects (introduced by Attiya, Guerraoui and Kouznetsov).