How can I use shared_mutex in C++?

How can I use shared_mutex in C++?

You can use shared_mutex to allow multiple threads to read shared data while ensuring exclusive access for writing.

Can you show me a code example?

Sure! Here's a simple example:

#include <iostream>
#include <shared_mutex>
#include <thread>
#include <vector>

std::shared_mutex mutex;
int shared_data = 0;

void read_data() {
    std::shared_lock<std::shared_mutex> lock(mutex);
    std::cout << "Reading data: " << shared_data << std::endl;
}

void write_data(int value) {
    std::unique_lock<std::shared_mutex> lock(mutex);
    shared_data = value;
    std::cout << "Writing data: " << shared_data << std::endl;
}

int main() {
    std::vector<std::thread> threads;
    for (int i = 0; i < 5; ++i) {
        threads.emplace_back(read_data);
    }
    for (int i = 0; i < 5; ++i) {
        threads.emplace_back(write_data, i);
    }
    for (auto& t : threads) {
        t.join();
    }
    return 0;
}

This code demonstrates reading and writing with shared_mutex.

What are the advantages of using shared_mutex?

The main advantage is that it allows multiple threads to read data simultaneously while preventing write access, improving performance in read-heavy scenarios.