These are some of the benefits of the Singleton pattern:
- Globally accessible: We can use the Singleton pattern to create a global access point to resources or services.
- Control concurrency: The pattern can be used to limit concurrent access to shared resources.
These are some of the drawbacks of the Singleton pattern:
- Unit testing: If overly used, the Singleton can make unit testing very difficult. We might end up with Singleton objects being dependent on other Singletons. If one is missing at any moment, the chain of dependency gets broken. This issue often happens when combining Facade and Singleton to set up front-facing interfaces to core systems. We end up with an array of manager classes, each managing a specific core component of the game, all dependent on each other to function. Therefore, it becomes impossible to test and debug in isolation.
- Laziness: Because of its ease of use, the Singleton is a pattern that can quickly instill faulty programming...
