Garbage collector

A garbage collector (GC) is a form of automatic memory management. The primary purpose is to find and reclaim memory that is no longer in use by the program, thus preventing memory leaks and optimizing memory usage. In essence, the garbage collector monitors objects in a program, determines which objects are no longer reachable (meaning they cannot be accessed or used by the program anymore), and then frees the memory allocated to those objects for future use.

Purposes

• Prevents Memory Leaks: By automatically cleaning up unused memory, it helps prevent your program from using more and more memory over time, which could slow it down or cause crashes.
• Improves Developer Productivity: Developers can focus on writing code without worrying about memory management.

Approaches

• The most common approach is Mark and Sweep. It marks all reachable objects and then frees the memory of those that aren't marked.

• Some garbage collectors use Reference Counting, where each object has a count of the number of references to it. When an object's reference count drops to zero, it can be safely deallocated. However, this approach has limitations, particularly with cyclic references (where two or more objects reference each other but are otherwise unreachable).