What is thread-local storage in C++?

What is thread-local storage in C++?

Thread-local storage (TLS) allows you to create variables that are unique to each thread. This means that each thread has its own instance of the variable, preventing data races.

How do I declare a thread-local variable in C++?

You can declare a thread-local variable using the thread_local keyword. For example: thread_local int myVar;.

Can you give me an example of using thread-local storage?

Sure! Here's a simple example:

#include <iostream>
#include <thread>

thread_local int threadVar = 0;

void increment() {
    threadVar++;
    std::cout << "Thread ID: " << std::this_thread::get_id() << " - Value: " << threadVar << std::endl;
}

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

What are the advantages of using thread-local storage?

The main advantages are improved performance by avoiding locks for shared data and preventing data races, as each thread has its own instance.