Semaphore and Shared Memory Project

This project provides an implementation of semaphore and shared memory operations in C using System V IPC mechanisms. It includes utility functions for creating, initializing, attaching, detaching, and destroying semaphores and shared memory segments. The code is structured to facilitate inter-process communication (IPC).

Table of Contents

• Introduction
• Features
• Directory Structure
• Dependencies
• Compilation
• Usage
  • Semaphore Functions
  • Shared Memory Functions
• Example
• License

Introduction

This project demonstrates the usage of System V semaphores and shared memory for implementing basic IPC functionalities. It is ideal for learning and experimenting with low-level synchronization and memory sharing between processes.

Features

• Create and initialize semaphores
• Perform P (wait) and V (signal) operations on semaphores
• Delete semaphores
• Create, attach, and destroy shared memory segments
• Utility functions for printing semaphore and shared memory details
• Template main.c file to guide implementation of a complete IPC workflow

Directory Structure

project/
├── semaphore.c         # Implementation of semaphore-related functions
├── semaphore.h         # Header file for semaphore
├── shared_memory.c     # Implementation of shared memory-related functions
├── shared_memory.h     # Header file for shared memory
├── main.c              # Template for implementing a full IPC workflow
├── Makefile            # Build instructions (optional)
└── README.md           # Project documentation

Dependencies

• GCC compiler
• System V IPC headers (e.g., <sys/types.h>, <sys/ipc.h>, <sys/sem.h>, <sys/shm.h>)

Compilation

To compile the project, use the following command:

gcc -o ipc semaphore.c shared_memory.c main.c -std=c99

This will generate an executable named ipc.

Usage

Semaphore Functions

• get_semaphore: Create or retrieve a semaphore using a file path and project ID.
• init_semaphore: Initialize the semaphore with a specified value.
• p: Perform the wait (decrement) operation.
• v: Perform the signal (increment) operation.
• delete_semaphore: Remove a semaphore.
• sem_printer: Print details of a semaphore.

Shared Memory Functions

• get_shared_memory: Create or retrieve a shared memory segment.
• attach_shared_memory: Attach the shared memory segment to the process's address space.
• detach_shared_memory: Detach the shared memory segment from the process's address space.
• destroy_shared_memory: Remove a shared memory segment.
• shm_printer: Print details of a shared memory segment.

Main Program Template (main.c)

The main.c file provides a template for implementing a complete workflow combining semaphores and shared memory. The sections include:

• Creation of semaphores and shared memory
• Initialization of resources
• Inter-process synchronization and memory sharing logic
• Cleanup and resource deallocation

The template allows users to implement custom logic for IPC use cases.

Example

Semaphore Example

semaphore sem;
get_semaphore(&sem, "file_path", 'A');
init_semaphore(sem, 1);
p(sem); // Wait operation
v(sem); // Signal operation
delete_semaphore(sem);

Shared Memory Example

sharedmem shm;
void *shm_addr;
get_shared_memory(&shm, "file_path", 'B', 1024);
attach_shared_memory(&shm_addr, shm);
// Use shared memory (e.g., read/write)
detach_shared_memory(shm_addr);
destroy_shared_memory(shm);

License

This project is open-source and available under the MIT License. Feel free to use, modify, and distribute it as needed.