POSIX- Operating Systems: 2nd Project Solved

Goal: In both projects you will implement a system of pizza order and delivery with the use of POSIX threads package (pthreads). In this second assignment there have been added deliverers who deliver the orders to the clients. The way the cooks perform is also changed. Your code must work properly on the virtual machine that was shown in the labs (link can be found in eclass). Both of these projects are designed for groups of three (3) people, but they can be completed in smaller groups too. The grade of this 2nd task represents 10% of the final grade (i.e. 1 points out of 10).

Objective: The pizzeria has 𝑁cook cooks, 𝑁oven ovens and 𝑁deliverer deliverers. The first orderis made at the time 0, and every next order is made after a random period of time and it rangesin the interval [Torderlow, Torderhigh]. Every order includes a random integer number of pizzas in the interval [Norderlow, Norderhigh]. The order has to wait until a cook is available. When a cook is available, a Tprep amount of time is required for each pizza to be prepared for the oven. Then, the cook waits until an oven is available. When an oven is available, all pizzas of the particular order go into the same oven and bake for Tbake amount of time. Note that the cook is available for a next order right after placing the pizzas in the oven (he does not wait for the pizzas to be baked). When the pizzas are baked, the oven turns automatically off and waits for a deliverer. When a deliverer is available, he/she takes all pizzas of the particular order out of the oven (which is then available for another order). He/she then packs the order and delivers it to the client. The delivery lasts a random (integer) period of time in the interval [Tlow, Thigh]. After the delivery, the deliverer needs the same amount of time to return to the pizzeria and to take on the next order. Every cook deals with only one order each time from the moment the order is handed to him/her until it is placed inside the oven. Every deliverer delivers only one order each time he/she goes out of the pizzeria.

Input and data: The following constants will be defined in a header file.

𝑁cook = 2 cooks (1/3 in comparison to the 1st assignment)
𝑁oven = 5 ovens
𝑁deliverer = 10 deliverers
Torderlow = 1 minute
Torderhigh = 5 minutes
𝑁orderlow = 1 pizza
𝑁orderhigh = 5 pizzas
Tprep = 1 minute
Tbake = 10 minutes
Tlow = 5 minutes
Thigh = 15 minutes
Your program will take two (exactly) parameters, which will represent the number of clients (𝑁cust) and random seed for random number generator.

Project Output: For each order, when it is received by the client, the following message must be printed:

Order with number <oid> has been delivered in <X> minutes and was cold for <Y> minutes.
The order of each order’s output message will be random, but they should not be mixed. The time <X> represents the period from the entry of the order until its delivery to the client, while time <Y>represents the period from completion of baking until its delivery to the client.

At the end of the program execution, the system will print the following:

Average and maximum delivery time Average and maximum time of orders being cold.
Code Structure: The initial thread of your program will create one thread per order (total of Ncust threads) to which you will pass a thread number (from 1 to Ncust) so that each thread is uniquely identified. Each thread will then perform the steps mentioned above until the order is delivered and will print the appropriate output. The initial thread will print the final output. You will need at least the following:

An integer variable and a mutex to count the number of available cooks and a condition variable to synchronize orders with cooks so that when no cooks are available, the orders are blocked. You will handle the ovens and distributors in a similar way.
Double variables and related mutexes for delivery and cold 
A mutex to lock the screen when you print the output.
Pay attention to the correct termination of the threads, to wait for them when needed and (mainly!) to properly free memory that was dynamically allocated.

Hints: 

All hints of the 1st assignment should also be followed in this 2nd It is recommended to start with the code of the previous assignment and extend it.
Be aware that cooks are released as soon as an oven is available and that the ovens are released as soon as at least 1 deliverer is available.
Also pay attention to the fact that the deliverers are busy even after the order has been delivered to the client, as they must return to the pizzeria.
Additional Notes: Your code must consist of a header file (including constants) and a .c code file for the program. These files must be named pizza2.h and pizza2.c. You should also write a report that describes the structure of your code and indicates any restrictions or additional features that you have implemented. The report must be named project2-report.pdf. Finally, you must include a test-res2.sh file which will compile and execute your program with 2 parameters, 100 (for the clients) and 1000 (for the initial seed).