2 de abril de 2024 05:32:36 ART
Welcome to ProgrammingHomeworkHelp.com, your trusted source for
online operating system assignment help. Operating systems lie at the heart of computing, serving as the bridge between hardware and software, making them a fundamental subject for any aspiring computer scientist or engineer. In this post, we'll delve into two challenging operating system questions, providing expert solutions and insights to help you grasp these concepts with clarity.
Question 1: Deadlock Detection and Recovery
#include
#include
#include
using namespace std;
// Function to detect deadlock
bool isDeadlock(int allocation[][3], int request[][3], int available[], int processes) {
vector work(3, 0);
vector finish(processes, false);
// Initializing work with available resources
for (int i = 0; i < 3; ++i)
work = available;
int count = 0;
// Iterate until all processes are finished or deadlock is detected
while (count < processes) {
bool found = false;
for (int i = 0; i < processes; ++i) {
if (!finish) {
int j;
for (j = 0; j < 3; ++j)
if (request[j] > work[j])
break;
if (j == 3) {
// Process can be executed
finish = true;
found = true;
++count;
for (int k = 0; k < 3; ++k)
work[k] += allocation[k];
}
}
}
// If no process can be executed, deadlock detected
if (!found)
return true;
}
// No deadlock detected
return false;
}
int main() {
int processes = 5;
int allocation[][3] = {{0, 1, 0},
{2, 0, 0},
{3, 0, 2},
{2, 1, 1},
{0, 0, 2}};
int request[][3] = {{0, 0, 0},
{2, 0, 2},
{0, 0, 0},
{1, 0, 0},
{0, 0, 2}};
int available[] = {0, 0, 0};
if (isDeadlock(allocation, request, available, processes))
cout << "Deadlock detected!";
else
cout << "No deadlock detected.";
return 0;
}
Solution:
Deadlock occurs when processes indefinitely wait for resources held by other processes, resulting in a stalemate. The above code implements deadlock detection using the Banker's algorithm. Here's a breakdown of the solution:
- The isDeadlock function takes allocation, request, and available matrices along with the number of processes as input.
- It initializes the work vector with available resources and finish vector to track finished processes.
- It simulates resource allocation by checking if a process can be executed safely.
- If a process can't execute due to insufficient resources, it's marked as finished.
- If all processes are finished before deadlock, it returns false; otherwise, deadlock is detected.
Question 2: Process Scheduling Algorithms
#include
#include
#include
using namespace std;
struct Process {
int id;
int arrivalTime;
int burstTime;
int completionTime;
};
// Function to compare processes based on arrival time
struct CompareArrival {
bool operator()(const Process& p1, const Process& p2) {
return p1.arrivalTime > p2.arrivalTime;
}
};
// Function to perform Shortest Job First (SJF) scheduling
void SJFScheduling(vector& processes) {
int currentTime = 0;
priority_queue, CompareArrival> pq;
for (const auto& process : processes)
pq.push(process);
while (!pq.empty()) {
Process currentProcess = pq.top();
pq.pop();
currentProcess.completionTime = currentTime + currentProcess.burstTime;
currentTime = currentProcess.completionTime;
cout << "Process " << currentProcess.id << " completed at time " << currentProcess.completionTime << endl;
}
}
int main() {
vector processes = {{1, 0, 3, 0},
{2, 1, 5, 0},
{3, 2, 2, 0},
{4, 3, 8, 0},
{5, 4, 4, 0}};
SJFScheduling(processes);
return 0;
}
Solution:
Scheduling algorithms determine the order in which processes are executed on a CPU. The provided code implements Shortest Job First (SJF) scheduling, where processes are executed based on their burst times. Here's how the solution works:
- The SJFScheduling function takes a vector of processes as input.
- It initializes a priority queue (pq) to store processes based on arrival time.
- Processes are inserted into the priority queue.
- At each iteration, the process with the shortest burst time is selected for execution.
- The completion time of each process is calculated based on the current time.
- Finally, the completion times of all processes are displayed.
Conclusion
Mastering operating system concepts is essential for any aspiring computer scientist or engineer. Through the provided solutions, we've explored deadlock detection using the Banker's algorithm and Shortest Job First scheduling. Understanding these concepts will not only help you ace your assignments but also prepare you for real-world challenges in operating system design and implementation. For further assistance with your operating system assignments, don't hesitate to reach out to ProgrammingHomeworkHelp.com.
Este post foi editado por thomas brown em 2 de abril de 2024 05:34:21 ART"
