Understanding the Singleton design pattern
Singleton provides you with a mechanism to have one, and only one, object of a given type and provides a global point of access. Hence, Singletons are typically used in cases such as logging or database operations, printer spoolers, and many others, where there is a need to have only one instance that is available across the application to avoid conflicting requests on the same resource. For example, we may want to use one database object to perform operations on the DB to maintain data consistency or one object of the logging class across multiple services to dump log messages in a particular log file sequentially.
In brief, the intentions of the Singleton design pattern are as follows:
- Ensuring that one and only one object of the class gets created
- Providing an access point for an object that is global to the program
- Controlling concurrent access to resources that are shared
The following is the UML diagram for Singleton:
A simple way of implementing...
