Garbage Collection

 Certainly! Garbage collection is a crucial aspect of the Java Virtual Machine (JVM) architecture. Let me break it down for you:

1. Memory Management:

   • The JVM divides memory into different regions, including the heap and the stack.
   • The heap is where objects are allocated, and it’s further divided into the Young Generation and the Old Generation.

2. Young Generation:

   • New objects are created in the Young Generation.
   • The Young Generation consists of three areas: Eden Space and two Survivor Spaces (S0 and S1).
   • Objects initially reside in Eden Space.
   • When Eden Space fills up, a minor garbage collection occurs.

3. Minor Garbage Collection:

   • During minor GC, live objects are moved from Eden Space to one of the Survivor Spaces.
   • Objects that survive multiple minor GC cycles are eventually promoted to the Old Generation.

4. Old Generation:

   • Long-lived objects reside in the Old Generation.
   • When the Old Generation fills up, a major garbage collection (also known as a full GC) occurs.

5. Major Garbage Collection:

   • Full GC scans the entire heap (both Young and Old Generations).
   • It reclaims memory by identifying and collecting unreachable objects.
   • This process can be expensive in terms of time and resources.

6. Garbage Collection Algorithms:

   • The JVM uses different algorithms for garbage collection, such as:
     • Serial GC: Single-threaded, suitable for small applications.
     • Parallel GC: Multithreaded, good for throughput.
     • Concurrent Mark-Sweep (CMS) GC: Minimizes pause times.
     • G1 (Garbage-First) GC: Balances throughput and latency.

Remember that garbage collection aims to free up memory by reclaiming objects that are no longer reachable. It’s an essential part of maintaining a healthy JVM environment!