How do I implement semaphores in C++?

How do I implement semaphores in C++?

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

Yes, please provide a code example.

Here's a simple example:

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

std::binary_semaphore sem(1); // Initialize semaphore with 1

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

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

What does the acquire and release function do?

The acquire function decreases the semaphore count, blocking if the count is zero, while release increases it, allowing other threads to proceed.