What is std::shared_mutex in C++14?

Can you explain what std::shared_mutex is in C++14?

Sure! std::shared_mutex is a synchronization primitive that allows multiple threads to read shared data concurrently while ensuring exclusive access for writing.

How does it differ from std::mutex?

Unlike std::mutex, which allows only one thread to access the resource at a time, std::shared_mutex allows multiple threads to read simultaneously, but only one thread can write.

When should I use std::shared_mutex?

You should use std::shared_mutex when you have a scenario with many readers and few writers, as it improves performance by allowing concurrent reads.

Can you provide a code example of using std::shared_mutex?

Certainly! Here's a simple example:

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

std::shared_mutex mutex;
int shared_data = 0;

void reader() {
    std::shared_lock lock(mutex);
    std::cout << "Reading: " << shared_data << std::endl;
}

void writer() {
    std::unique_lock lock(mutex);
    shared_data++;
    std::cout << "Writing: " << shared_data << std::endl;
}

int main() {
    std::thread t1(reader);
    std::thread t2(writer);
    t1.join();
    t2.join();
    return 0;
}