shanhe72101

Restore reader_count in case of failure in rwlock_rdlock_impl

5

### What problem does this PR solve? Issue Number: Fix #3051 Problem Summary: ### What is changed and the side effects? Changed: Side effects: - Performance effects: - Breaking backward...

**Describe the bug** bthread::RWLock在写者持有锁期间，读者try_lock_for锁超时失败，符合预期，但写者释放锁之后，并且没有读者的情况下，新的写者无法获取锁 初步排查原因如下 apache_brpc/src/bthread/rwlock.cpp 函数rwlock_rdlock_impl 首先会给reader_count加1，超时失败并未恢复计数 因为没有替代方案，严重影响项目进度，跪求大佬们尽快响应，感激不尽！ **To Reproduce** **Expected behavior** **Versions** OS: Ubuntu 24.04.1 LTS Compiler: gcc 13.3 brpc:1.11.0 protobuf: **Additional context/screenshots** 为了能够使用std::unique_lock和std::shared_lock管理锁，封装了一个代理类，希望官方能够原生支持，或者推出自己的unique_lock和shared_lock，感谢 class SharedTimedMutex { public:...