It's not hard to see why synchronization can have a significant effect on program performance; flushing the cache frequently can be expensive.
不难看出为什么同步会对程序的性能影响这么大；频繁地刷新缓存代价会很大。
2
The cost difference between an uncontended synchronization and a contended one is huge; a simple test program suggested that a contended synchronization is 50 times slower than an uncontended one.
All updates to recoverable resources or requests to other transactional systems are now part of this unit-of-work, until a synchronization point (syncpoint) is reached within the CICS program.