Node.js, V8, and Memory Management.

C++ in Node.js?

Something interesting for people to know who just started with Node.js is that Node.js is built on C++ through the V8 JavaScript engine, that creates a powerful runtime environment. So C++ provides the low level performance and system level interactions that JavaScript alone cannot achieve. Now you might ask what does C++ actually help with? :-

• Implementing core Node.js modules

• Managing memory allocation and garbage collection

• Handling system level operations

• Creating native modules that extend JavaScript capabilities

V8: The JavaScript Engine

V8 is an open source engine, created by Google, and it’s job is:

• Compiling JavaScript to machine code

• Executing JavaScript at high speed

• Managing memory allocation and garbage collection

• Providing a runtime environment for JavaScript

Memory Management in Node.js

Memory Architecture

Node.js memory is structured into distinct segments:

1. Stack Memory:

   • Stores temporary data

   • Manages function calls and local variables

   • Fixed size and very fast access

   • Used for primitive data types and reference pointers

   • Automatically managed by the runtime

2. Heap Memory:

   • Dynamic memory allocation

   • Stores complex objects, closures, and dynamically created data

   • Managed by garbage collection

   • Flexible but slower compared to stack

   • Supports larger and more complex data structures

Generational Garbage Collection

V8 uses a generational method to make memory management more efficient.

Young Generation:

• Deals with new, short-lived objects.

• Runs garbage collection often and quickly.

• Most objects don’t last long and get removed fast.

• Designed for fast memory recycling.

Old Generation:

• Stores objects that last longer.

• Garbage collection happens less often but takes more time.

• If an object survives multiple young generation cleanups, it moves here.

• Needs deeper memory analysis to manage properly.