Initial Code

Co-authored-by: Djalim Simaila <DjalimSimaila@users.noreply.github.com>
Co-authored-by: Romain CLEMENT <rc2301@orange.fr>

main.cpp

@@ -1,9 +1,82 @@
 #include <iostream>
+#include <chrono>
+#include <semaphore>
+#include <thread>
+#include <vector>
+#include <mutex>
 
 using namespace std;
 
+mutex cout_mutex;
+#define print(X) cout_mutex.lock(); cout << X << endl; cout_mutex.unlock();
+#define N 25
+
+// GLOBAL VARIABLES
+counting_semaphore free_chairs(N);
+binary_semaphore barber_free(1);
+binary_semaphore barber_sem(1);
+
+void get_haircut(size_t id)
+{
+    this_thread::sleep_for(chrono::seconds(10));
+    print("Client " << id << " got a haircut");
+}
+
+void cutHair()
+{
+    this_thread::sleep_for(chrono::seconds(10));
+    print("Barber cut hair");
+}
+
+void client(size_t id)
+{
+    print("Client " << id << " arrived");
+    bool isAChairFree = free_chairs.try_acquire();
+    if (!isAChairFree){
+        print("no chairs available");
+        print("Client " << id << " left");
+        return; //Bye bye  
+    } 
+
+    //wait for barber    
+    barber_free.acquire();
+    print("Client " << id << " woke the barber up");
+    barber_sem.release();
+    // Get a haircut
+    get_haircut(id);
+    // Bye bye;
+    free_chairs.release();
+    print("Client " << id << " left");
+}
+
+void barber()
+{
+    while (true) {
+        print("Barber is sleeping");
+        barber_sem.acquire();
+        print("Barber woke up");
+        cutHair();
+        barber_free.release();
+    }
+}
+
+
 int main()
 {
-    cout << "Hello World!" << endl;
+    barber_sem.acquire();
+    thread barber_thread(barber);
+    print("Client will arrive");
+    vector<thread> clients {};
+    for(size_t i = 0; i < N+1; ++i)
+    {
+        thread t(client, i);
+        clients.push_back(std::move(t));
+    }
+
+    barber_thread.join();
+    for (auto &client: clients) {
+        client.join();
+    }
+
     return 0;
 }