17. The medium of claim 16 , wherein the begin instruction is an xbegin instruction, the assignment is associated with a mov instruction, and the end instructions is an xend instruction.
16. The medium of claim 15 , wherein the functions comprise a first function an invocation of which is inserted following a begin instruction of the transaction block, a second function an invocation of which is inserted proximate to the assignment, and a third function an invocation of which is inserted following an end instruction of the transaction block and outside of the transaction block.