Garbage Collector

Garbage Collector is the program running in the background that looks into all the objects in the memory and find out objects that are not referenced by any part of the program. All these unreferenced objects are deleted and space is reclaimed for allocation to other objects.

One of the basic ways of garbage collection involves three steps:

1.     Marking: This is the first step where garbage collector identifies which objects are in use and which ones are not in use.

2.     Normal Deletion: Garbage Collector removes the unused objects and reclaim the free space to be allocated to other objects.

3.     Deletion with Compacting: For better performance, after deleting unused objects, all the survived objects can be moved to be together. This will increase the performance of allocation of memory to newer objects.

There are five types of garbage collection types that we can use in our applications. We just need to use JVM switch to enable the garbage collection strategy for the application. Let’s look at each of them one by one.