小记图灵奖得主Tony Hoare博士的演讲

Dr. Tony Hoare

Quick Sort的发明人，领导设计了 Algol 60语言
1977年开始，任职于牛津大学
1980年被ACM授予“图灵奖”
2000年由英女王授予爵士爵位
现任微软剑桥研究院的高级研究员

系里的教授都很给牛人面子，几乎悉数到场。讲演是关于

Compensable Transactions

内容提要：

A compensable transaction is a program that performs an action accompanied by a program that performs a compensation for that action. After completion of the action, a later call of the compensation will undo its effects, as far as possible. Long sequences of compensable transactions can be composed into a single long-running transaction, which is still compensable. A long-running transaction is more general than the typical database transaction. It does not have to observe the criterion of independence, so it can communicate with its external environment, or even with the real world.

However, long-running transactions still observe the principle of atomicity: each transaction either succeeds as a whole, or fails as a whole, leaving the world in (nearly, but not exactly) the same state as it started in. I will present a semantics for long-running transactions in the form of structured flowcharts satisfying certain natural healthiness conditions. I will show how they can be composed and even nested by normal programming constructions.

理 论性很强的关于进程优化的，如何更好的架构编程体系。虽然看得出Tony Hoare博士力图使演讲变得生动有趣，无奈很枯燥的话题还是让很多外行人昏昏欲睡，我就是其一。老婆更是在一旁折纸花。大致知道他在讲如何让一个失败了 的进程回到最近的，还没发生错误的地方，将损失降至最小。演讲快结束时，系里两个大牛人（也是大忙人）终于扛不住先离开了，一个是Euro Graph的主席，一个是ACM的Fellow.