Development related to Operating Sytems algorithms and techniques:
- Threads
- Barriers
- Parallel programming synchronization
- Process Scheduling
- Memory Management
This app consists of two parts:
An implementation of a shell (ep1sh.c), using the fork() syscall and a loop structure. It has the commands date and chown : built-in (using exactly the structure provided before). It also executes any command using the execvp() syscall.
And also, a multithreaded implementation of three process scheduling algorithms for CPU's, namely the Shortest Job First, Round Robin and Priority Scheduler. The program will simulate a list of processes providaded in a trace file via command line arguments. It also supports a debug flag 'd', to print the events as they occur.
This is an implementation of a velodrome bike racing simulator, fully concurrent (each biker is a thread), and all the threads are synchronized using barriers, in our case, using the pthread_barrier from the pthread library. The race is simulated with strict rules for the scores of each biker, for details of the rules, please refer to the assigment.pdf file (or e-mail me :p). Each biker has some possible moves, and each one of them behave like an automata, and we synchronize the movements of the bikers using mutexes, namely pthread_mutexes.
The simulator constructs a dependency graph each step, and calculates the Strongly Connected Components to detect cycles in the graph using Tarjan's Algorithm, to prevent deadlocks in the simulation.
Simulator of virtual and physical memory allocation, using a trace file for the processes list (each process has a default size and make some memory access in a given time). The memory-simulator implements the following algorithms:
Virtual memory allocation:
- Best Fit
- Worst Fit
- Quick Fit
Pages substitution(for page faults):
- Optimal
- FIFO
- LRU (bit matrix implementation)
- LRU (bit counter implementation)
