This PR is an attempt to reduce contention in concurrent dictionaries, replacing method calls using full locks with lock-free equivalents:
- dictionary.Count -> dictionary.Skip(0).Count()
- dictionary.Keys -> dictionary.Select(x => x.Key)
- dictionary.Values -> dictionary.Select(x => x.Value)
The most frequent usages of these methods are: CashBook, SecurityManager, UniverseManager and indirectly, SecurityPortfolioManager.
The reasons for this update are explained very clearly in this article:
https://arbel.net/2013/02/03/best-practices-for-using-concurrentdictionary/
Stefano Raggi