C++ Thread Synchronization: std::mutex, RAII lock_guard & Deadlock Prevention

When multiple threads read and write shared memory concurrently, access must be synchronized using a Mutex (Mutual Exclusion) to protect Critical Sections.

Eliminating Race Conditions with std::lock_guard

#include <iostream>
#include <thread>
#include <vector>
#include <mutex>

int sharedCounter = 0;
std::mutex counterMutex; // Mutex protecting sharedCounter

void safeIncrement() {
    for (int i = 0; i < 10000; ++i) {
        // RAII: Locks mutex in constructor, unlocks deterministically in destructor!
        std::lock_guard<std::mutex> lock(counterMutex);
        sharedCounter++;
    }
}

int main() {
    std::vector<std::jthread> workers;
    for (int i = 0; i < 10; ++i) {
        workers.emplace_back(safeIncrement);
    }
    workers.clear(); // Waits for all threads to join

    std::cout << "Final Safe Counter: " << sharedCounter << "\n"; // Exactly 100,000!
    return 0;
}