write lock-out

Pattern# 5: The cheap read-write lock trick

模式5：开销较低的读-写锁策略

A strategy locking constraint resources using write lock and read lock is presented to consider the time delay of data transmission and improve the efficiency of concurrent operation. The realization of main algorithms for constraint network solving is given.

提出了写锁和读锁2种加锁状态的约束资源的锁定策略，来考虑网络传输的延时性和提高并行操作的效率，并给出了主要算法的实现说明。

The S lock allows concurrent applications that use read-only queries to access the target table, but applications attempting to write data to the table are prevented from doing so.

S锁允许使用只读查询的并发应用程序访问目标表，但是防止应用程序写数据到表中。

Based on this new method, it gives new algorithms and implementation on read/ write lock, queue lock and record lock.

为了演示这种新思路的特点和优点，笔者对几个常见问题（读写锁、排队锁和记录锁）给出了新的算法设计以及实现。

The distributed lock system is used to synchronize GOS steps when accessing data. The consistency of the distributed cache is guaranteed by updating strategies of write-through and write-invalidate.

分布式锁管理机制实现了GOS之间数据访问的同步协调，写通和写&无效的数据更新策略保证了GOS的缓存一致性。