Round Robin scheduler with Gantt Chart in C++

Round Robin (RR) Scheduler

Round Robin (RR) is a preemptive cpu scheduler in which processes run for a constant time quantum in turns. It is implemented using a FIFO queue.

Round Robin Example :

C++ program to implement Round Robin with gantt chart

Input format :

[number of processes]
[pid] [arrival time] [priority] [share] C [burst] I/O [burst] C [burst] ........... -1
....
[pid] [arrival time] [priority] [share] C [burst] I/O [burst] C [burst] .......... -1

First line describes number of processes.

Then Each of the next N lines describe : -

[pid] : process id.

[arrival time] : time this process was put into ready queue.

[priority] : priority assigned to a process. A lower value means higher priority 

[share] : % of tickets assigned in lottery (proportional share) scheduling. 

This is followed by sequence of bursts. Before each burst interval, there is a character indicating type of burst.

C : stands for CPU

I : stands for Input

O : stands for output device

-1 : indicates end of trace file

For Round Robin scheduling, time quantum shall be one.

We are assuming one CPU, one Input device and one output device.

Input/output devices follow first come first serve policy i.e. if a process is assigned an input/output device, this device can not be assigned to any other process till its burst is over.

Input ( process.dat)

3
1   0   2   1   C   2   I     2   C   3   -1
2   2   0   2   C   4   O     2   C   4   -1
3   0   1   1   C   6   I     4   C   2   -1 

Output :

Use g++ rr.cpp to compile and ./a.out to run on linux 

 File description :

rr_codespeedy
├── Process.h      ( header file containing helper methods)
├── process.dat    ( input file )
└── rr.cpp           ( C++ rr scheduler program )

0 directories, 3 files

Requirements: 

C++ 11 or later