Pthread scheduling

Firstly, trains must enter to the check point. In this train station, there is one check point serving trains. As a result, only one train can enter to the check point at a time even if several trains arrived at the same time to the station. At the check point, the station's workers determine the priority of the entered train. Moreover, they estimate the time that the train will take it in the common line. Usually the priority of the train is given depending on their types [passenger train, train of goods (full), and train of goods (empty)]. Obviously, if there are trains with same type, the one with earlier arrival time is assigned a higher priority. And in the case of tie, the higher priority is given to one train in random. Similarly, the time a train takes it in the common line is decided based on the train's type. For instance, a passenger train is given a time ranging from 20-30 minutes, a train of goods (full) from 40-50 minutes, and a train of goods (empty) from 30-40 minutes. Design a system for the train station which automates the operation of admitting the trains to the station and scheduling them to the common line. At the end, calculate the average waiting time and average turnaround time for all trains coming to the train station. Assume the time is given in minutes. Use pthread library in the Linus OS to implement your system.