README.en.md

Pizza Order Management System with POSIX Threads

This project implements a pizza order management system using POSIX threads (pthreads) and synchronization mechanisms (mutexes, condition variables) on Linux/Lubuntu. The code simulates the concurrent operation of customers, cooks, ovens, packers, and delivery personnel.

Functionality Overview

1. Order Process

• Each customer is represented as a separate thread.
• Customers connect at random intervals and place orders:
  • Random number of pizzas (1-5).
  • 60% probability for a plain pizza (Cplain = €10) and 40% for a special pizza (Cspecial = €12).
  • 10% chance for the order to fail.

2. Resource Management

• Resource tracking using mutexes and condition variables:
  • Cooks: Ncook = 2 (prepares pizzas in Tprep = 1 minute/pizza).
  • Ovens: Noven = 15 (bakes pizzas in Tbake = 10 minutes).
  • Packers: Npacker = 2 (packs pizzas in Tpack = 1 minute/pizza).
  • Delivery Personnel: Ndeliverer = 10 (delivers orders in random time 5-15 minutes).

3. Statistics

At the end of execution, the system displays:

• Total income, failed/successful orders.
• Sales count per pizza type.
• Average and maximum delivery time.
• Waiting times for baking and packing.

Code Structure

• Main File: pizzeria.c
  Contains thread creation logic, resource synchronization, and statistics.
• Header File: pizzeria.h
  Defines constants (e.g., number of cooks, timers).
• Test Script: test-res.sh
  Compiles and runs the code:

  gcc pizzeria.c -o main -pthread
  ./main 100 1000  # 100 orders, seed=1000```
  

Notes

• The code is written for Linux/Lubuntu.
• Parallelism is used to simulate concurrent processes (e.g., multiple customers ordering simultaneously).

Example Execution

$ ./test-res.sh
Order #1 has been registered.
Cook #1 is handling order #1
...
Total income: €1500
Failed orders: 5
Successful orders: 95
Total special pizzas sold: 38
Total normal pizzas sold: 57