Can you explain the working mechanism of the generation system during garbage collection?

The generational garbage collection system is based on the observation that most objects in memory have a short lifespan. It divides the heap into several generations (usually 3):

• Young Generation: where new objects are allocated. Garbage collection here occurs frequently and quickly, cleaning up objects that quickly become unnecessary.
• Tenured or Old Generation: objects that survive several collections in the young generation are moved here. Collection occurs less frequently, as objects are considered more stable.
• Permanent Generation (or Metaspace in Android): stores class metadata and other administrative information.

Working mechanism:

1. When an object is created, it is placed in the young generation.
2. If the object survives several collection cycles in the young generation, it is "promoted" to the older generation.
3. Garbage collection is first triggered in the young generation (Minor GC), which quickly frees memory.
4. If the old generation fills up, a full garbage collection (Full GC) is triggered, which is more time-consuming.

This approach increases garbage collection efficiency, reducing delays and system load.