// Protects everything that follows, except mWriterThreadId and mRecursiveUpgrade
CRITICAL_SECTION mLock;
// Semaphore to wait on for a read lock
HANDLE mSemaReader;
// Semaphore to wait on for a write lock
HANDLE mSemaWriter;
// Number of threads waiting for a write lock.
int mWriterWaiting;
// Number of times the writer entered the write lock.
int mWriterActive;
// Number of threads inside a read lock. Note that this does not include
// recursive read locks.
int mReaderActiveThreads;
// Whether or not the current writer obtained the lock by a recursive 
// upgrade. Note that this member might be set outside the critical
// section, so it should only be read from by the writer during his
// unlock.
bool mRecursiveUpgrade;
// This member contains the current thread id once for each
// (recursive) read lock held by the current thread in addition to an 
// undefined number of other thread ids which may or may not hold a 
// read lock, even inside the critical section (!).
std::multiset<unsigned long> mReaderActive;
// If there is no writer this member contains 0.
// If the current thread is the writer this member contains his
// thread-id.
// Otherwise it can contain either of them, even inside the 
// critical section (!).
// Also note that it might be set outside the critical section.
unsigned long mWriterThreadId;

现在的基本想法是:

全天候的<代码>mWriterWaiting和mWriterActive由不间断的校正进行。

<代码>mWriterThreadId和mReaderActive是不可能做到的,因为等待读写者在释放时需要插入自己。

因此,这条规则是,你不得接触到这两名成员、<>除外>,以检查你是否持有24小时或现任作者,具体来说,这不得用来检查是否存在任何>读物/作者,因为你必须使用(有点多余但出于这一原因必须的)<编码>mReaderActiveThreads和mWriterActive。