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What is the main drawbacks of using Singleton design pattern?
One of the main disadvantages of singletons is that they make unit testing very hard. They introduce global state to the application. The problem is that you cannot completely isolate classes dependent on singletons. When you are trying to test such a class, you inevitably test the Singleton as well.
Are there any problems if we implement singleton in multi threading environment?
If you use the singleton before you set up the threads, there will be no problem. If this is a concern, you may consider initialising the singleton first. You can also solve this by using the synchronized keyword in the method declaration.
What are the two problems that the Singleton pattern solves?
The pattern solves two problems at the time. The Singleton pattern can mask bad design, for instance, when the components of the program know too much about each other. The pattern requires special treatment in a multithreaded environment so that multiple threads won’t create a singleton object several times.
Is the singleton pattern thread safe in C #?
Performing lock is heavy. So to avoid the lock first we need to check the null value. This is also thread safe and it is the best way to achieve the best performance. Please have a look at the following code. Another version of Singleton where the following line of code creates the Singleton instance at the time of application startup.
Why is a singleton considered an anti pattern?
Singleton is mostly considered an anti-Pattern, because it brings inherent complexity to the system in terms of testing. Only DI frameworks (Spring, Dagger, etc) should be allowed to create Singletons for you rather than you writing the singletons.
Why do we need a singleton in C #?
Its purpose is to avoid the expensive lock operation which is only going to be needed once (when the singleton is first accessed). The implementation is such because it also has to ensure that when the singleton is initialized there will be no bugs resulting from thread race conditions.
What is eager loading in singleton design pattern?
“The Eager loading in singleton design pattern is nothing a process in which we need to initialize the singleton object at the time of application start-up rather than on demand and keep it ready in memory to be used in future.”