MutexSemaphore.cpp

#include "MutexSemaphore.h"

Semaphore::Semaphore(int initialValue) : S(initialValue) {}

void Semaphore::P() {
  std::unique_lock<std::mutex> lock(mutex_); // Acquire mutex
  cv_.wait(lock, [this] { return S > 0; }); // Wait until S > 0
  S--;
}

void Semaphore::V() {
  std::lock_guard<std::mutex> lock(mutex_); // Acquire mutex
  S++;
  cv_.notify_one(); // Notify a waiting thread
}