中文摘要：

针对基于替代/补偿的实时事务模型中的优先级分派问题,提出基于价值密度的替代与事务优先级分派策略PBAC.在PBAC中,替代优先级基于替代的价值密度,并与替代的执行时间和紧迫性相关,事务优先级继承自替代的优先级,并受事务执行度的影响.仿真实验结果证明,该策略使系统可以更好地对基于替代/补偿的事务模型进行调度.

英文摘要：

Aiming at real-time transaction model based on alternative/compensate, this paper studies the alternative and transaction priority assignment issue and proposes an alternative and transaction priority assignment strategy based on the value density named Priority Based on Alternative and Compensation（PBAC）. In PBAC, the alternative priority based on the value density relates to the execution time and urgency of alternative. Transaction priority inherits from alternative, and it is affected by the implementation degree of transaction. Simulation experimental result proves that PBAC enables the system favors to scheduling the transaction model based on alternative/compensate better.