BloombergLP::bslmt::ReadLockGuard::ReadLockGuard

Create a scoped guard that conditionally manages the specified lock (if non‐null) and invokes lock‐>lockRead() if the specified alreadyLockedFlag is false. Supplying a null lock has no effect. The behavior is undefined unless the state of lock (if non‐null) is consistent with alreadyLockedFlag. Note that alreadyLockedFlag is used to indicate whether lock is in an already‐locked state when passed, so if alreadyLockedFlag is true the lock method will not be called on the supplied lock. Also note that lock must remain valid throughout the lifetime of this guard, or until release is called.