How can I use semaphores in C++ for thread synchronization?

How can I use semaphores in C++ for thread synchronization?

You can use the <semaphore> header in C++20 to implement semaphores. Would you like a code example?

Yes, please provide a simple example.

Here's a basic example:

#include <iostream>
#include <semaphore.h>
#include <thread>

std::binary_semaphore sem(1);

void accessResource(int id) {
    sem.acquire(); // Wait for the semaphore
    std::cout << "Thread " << id << " is accessing the resource." << std::endl;
    std::this_thread::sleep_for(std::chrono::seconds(1));
    std::cout << "Thread " << id << " is done accessing the resource." << std::endl;
    sem.release(); // Release the semaphore
}

int main() {
    std::thread t1(accessResource, 1);
    std::thread t2(accessResource, 2);
    t1.join();
    t2.join();
    return 0;
}

What are the advantages of using semaphores over mutexes?

Semaphores allow multiple threads to access a resource concurrently, while mutexes provide exclusive access. This can improve performance in scenarios where shared resources can be accessed by multiple threads simultaneously.