What is concurrency in C++ and how does the standard library support it?

What is concurrency in C++ and how does the standard library support it?

Concurrency in C++ allows multiple tasks to run simultaneously, improving performance. The C++ standard library provides features like threads, mutexes, and condition variables to manage concurrent execution.

Can you explain how to create a thread using the C++ standard library?

Sure! You can create a thread using the std::thread class. Here's a simple example:

#include <iostream>
#include <thread>

void hello() {
    std::cout << "Hello from thread!" << std::endl;
}

int main() {
    std::thread t(hello);
    t.join(); // Wait for the thread to finish
    return 0;
}

What are mutexes and why are they important in concurrency?

Mutexes are mutual exclusion objects that prevent multiple threads from accessing shared resources simultaneously, avoiding data races. They are crucial for maintaining data integrity in concurrent programming.

How do I use condition variables in C++?

Condition variables are used for thread synchronization. You can use std::condition_variable to block a thread until a particular condition is met. Here's a basic example:

#include <iostream>
#include <thread>
#include <condition_variable>
#include <mutex>

std::mutex mtx;
std::condition_variable cv;
bool ready = false;

void waitForSignal() {
    std::unique_lock<std::mutex> lock(mtx);
    cv.wait(lock, [] { return ready; });
    std::cout << "Thread proceeding after signal!" << std::endl;
}

int main() {
    std::thread t(waitForSignal);
    std::this_thread::sleep_for(std::chrono::seconds(1));
    {
        std::lock_guard<std::mutex> lock(mtx);
        ready = true;
    }
    cv.notify_one();
    t.join();
    return 0;
}