Transitions as Transactions

As newly developed transactional memory technology has received significant attention as a way to dramatically simplify sharedmemory concurrent programming, user-level transactional concurrent programming models have become a very interesting topic in the programming community. However, the fact is that, in existing transactional concurrent programming models, user-level mechanisms have not been well developed. The dilemma is how to make a balance between the performance and correctness of a program. Explicit concurrency among cooperative transactions can undoubtedly decrease the rate of conflicts and improve the performance, but it is harmful to the correctness. In this paper, a transactional concurrent programming approach, based on Petri nets, is presented, which can easily specify concurrency among transactions and do not aggravate programmers remarkably in writing correct transactional concurrent programs. In this approach, a special Petri net system with transition markings is developed. Although such a Petri net system is not defined conventionally, it is shown that its behavior can be simulated through a conventional net, so existing analysis and verification approaches for usual Petri nets can be applied indirectly.