Why Programs Use Stack, Heap, and Other Memory Segments

The virtual memory of a process is divided into several regions, each serving a specific purpose: code, data and BSS, heap, stack, the operating system’s kernel space, and potentially other segments. In this video, I go over why this segmentation is so important and what does each segment actually does.

SUMMARY
The main segments of a program's virtual space are:
• Text/Code: The executable instructions of the program. Loaded from the binary (compiled) file, found on the disk.
• Data & BSS: Global and static variables. The data segment stores initialized variables, while the BSS segment stores uninitialized variables.
• Heap: Memory area used for dynamic memory allocation during program runtime. Uses a memory allocator to track free and occupied memory addresses. Memory release is fast, but allocation could be slow (compared to the stack).
• Stack: Memory area used for storing function parameters, local variables, and the callers return address, among other things. It uses a data structure called a Stack Frame to encapsulate all information of an active function. It uses a simple pointer (Stack Pointer) to track the top of the stack. Memory allocation and release are very fast.
• OS Kernel: Reserved for the operating system’s pages. Helps the program to execute privileged (operating system) code such as reading and writing to a storage device or sending data over the network.

LINKS
📚 Computer Memory and Architecture E-Book Collection: https://buymeacoffee.com/bitlemonsoft...
📚 Inside the Core: How the CPU Works (E-Book): https://buymeacoffee.com/bitlemonsoft...
📚 Interrupts in Modern Computer Systems (E-Book): https://buymeacoffee.com/bitlemonsoft...
📚 The Anatomy of Virtual Memory (E-Book): https://buymeacoffee.com/bitlemonsoft...
📚 Beginner's Guide to CPU Caches (E-Book): https://buymeacoffee.com/bitlemonsoft...
❤ Support my work: https://buymeacoffee.com/bitlemonsoft...

SOURCES
The information in this video is mainly based on the book: Operating System Concepts (10th Edition) by Abraham Silberschatz, Peter B. Galvin, and Greg Gagne.

TABLE OF CONTENTS
00:00 Introduction to Processes
00:38 Virtual Memory Segments
01:53 Text/Code Segment
02:14 Data & BSS Segments
03:14 Heap Segment
04:07 Stack Segment
05:38 OS Kernel Segment

ATTRIBUTION
Some of the elements in the video were designed by vectorpocket / macrovector / rawpixel.com / Freepik at freepik.com.

#computerscience #memorymanagement #computermemory #operatingsystem #stack #heap