CSCI 3400 Process Scheduling

In this assignment, you will write a program that simulates a simple version of the process scheduling system in the computer processor. Your program will read a set of process information from an input file (processList.txt) and schedule their execution order using a Queue data structure. Every process in the file has an ID and a required time of execution (in ms). A sample input file is shown below:

5396 15
7550 9
6148 13
4048 1
7018 11
4104 4
1402 12
8278 19
1130 10
1530 7

As an example of above file, the process with ID=5396 needs 15 ms execution time. Similarly, the process with ID=7550 needs 9 ms execution time, etc. When a process in the queue is executed, its remaining execution time is reduced by 1ms. So, every process is expected to be executed multiple times until their remaining execution time is zero.

Initially, you will create a class called "Process". This class will have two attributes and several member functions. Please see details of the class below:

Once your class is ready, you will create a queue of "Process". You will use C++ STL Queue library for this queue object. You do not have to design a new queue class. See the reference link below:

https://www.geeksforgeeks.org/queue-cpp-stl/

Please note that function names of the STL queue class are not matching with the names of queue we implemented in class. Please use the STL function names accordingly. After creating the process queue, you will load all processes in file to the queue. First, you will print all processes and their execution times. For example:

Process: 7846 Remaining Time:20 ms
Process: 5396 Remaining Time:15 ms
Process: 7550 Remaining Time:9 ms
Process: 6148 Remaining Time:13 ms
Process: 4048 Remaining Time:1 ms
Process: 7018 Remaining Time:11 ms
Process: 4104 Remaining Time:4 ms
Process: 1402 Remaining Time:12 ms
Process: 8278 Remaining Time:19 ms
Process: 1130 Remaining Time:10 ms

Then the execution starts. In a while loop (while the queue is not empty), you will dequeue() (or pop() in the STL version) a process from the queue and execute it using the process execute() function. This execution is a very simple simulation, where only the execution time of the process is reduced by 1ms. If the remaining execution time is still greater than zero, then the process is sent back of the queue using the enqueue() (or push() in the STL version) function. If the remaining time is zero, "the process complete" message is printed on the screen. This way, in every iteration of the while loop, the process at the beginning of the queue is removed, executed, and added back (if not completed). See the following pseudo-code for the while loop:

while(process queue is not empty){
Take the process at the head of the queue using front() and pop()
Execute the process
if(the process time equals zero)
Print “Process with ID=X is completed”
Else
Print “Process with ID=X needs Y more ms of execution.”
Send the Process to the back of the queue using push()
Print “Process ID=X is sent back of the queue”
}

A sample screen output of a few execution steps is given below.

- Process: 7846 sent back of the queue! Remaining Time: 19ms
- Process: 5396 sent back of the queue! Remaining Time: 14ms
- Process: 7550 sent back of the queue! Remaining Time: 8ms
- Process: 6148 sent back of the queue! Remaining Time: 12ms
+ Process: 4048 is completed!
- Process: 7018 sent back of the queue! Remaining Time: 10ms
- Process: 4104 sent back of the queue! Remaining Time: 3ms
- Process: 1402 sent back of the queue! Remaining Time: 11ms
- Process: 8278 sent back of the queue! Remaining Time: 18ms
- Process: 1130 sent back of the queue! Remaining Time: 9ms
- Process: 7846 sent back of the queue! Remaining Time: 18ms
- Process: 5396 sent back of the queue! Remaining Time: 13ms
...

This while loop will run until all processes are completely executed. Then your program will end.