15 January 2007
Lampson: Lazy and Speculative Execution
9
Correctness: Actions Must Commute
nL; A = A; L     or     A; S = S; A
oA special case of A; B = A || B
n
nEnsured if
oL/S is purely functional
oL/S has no side effects and reads nothing A writes
oTransactions
▬Detect conflict, abort, and retry in the proper order
▬Often used for speculation, just aborting S
n