bthread::RWLock在写者持有锁期间，读者try_lock_for锁超时失败，会导致读者计数错误

[shanhe72101]

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: void lock() { rwlock.wrlock(); } bool try_lock() { return rwlock.try_wrlock(); } template<typename _Rep, typename _Period> bool try_lock_for(const std::chrono::duration<_Rep, _Period>& delay_time) { struct timespec ts; get_timespec_after_ms(&ts, delay_time); return rwlock.timed_wrlock(&ts); } void unlock() { rwlock.unlock(); } void lock_shared() { rwlock.rdlock(); } bool try_lock_shared() { return rwlock.try_rdlock(); } template<typename _Rep, typename _Period> bool try_lock_shared_for(const std::chrono::duration<_Rep, _Period>& delay_time) { struct timespec ts; get_timespec_after_ms(&ts, delay_time); return rwlock.timed_rdlock(&ts); } void unlock_shared() { rwlock.unlock(); } private: template<typename _Rep, typename _Period> void get_timespec_after_ms(struct timespec* ts, const std::chrono::duration<_Rep, _Period>& delay_time) { const auto delay_ns = std::chrono::duration_caststd::chrono::nanoseconds(delay_time).count(); clock_gettime(CLOCK_REALTIME, ts); ts->tv_sec += delay_ns / std::nano::den; ts->tv_nsec += delay_ns % std::nano::den; if (ts->tv_nsec >= std::nano::den) { ts->tv_sec += 1; ts->tv_nsec %= std::nano::den; } } bthread::RWLock rwlock; };