One of the exciting new features introduced in C++20 is the std::jthread class. It is a new addition to the Standard Library and is designed to simplify thread management in C++. With std::jthread, managing threads becomes more convenient and safer compared to the existing std::thread class.

What is std::jthread?

std::jthread is a thread management class that provides a high-level interface for creating and managing threads in C++. It is an improvement over the existing std::thread class, offering additional features and safety guarantees.

Creating a std::jthread

Creating a std::jthread is as simple as creating an instance of the class. Here’s an example:

#include <iostream>
#include <thread>

void myThreadFunction() {
    // The function executed in the thread
    std::cout << "Hello from thread!\n";
}

int main() {
    std::jthread myThread(myThreadFunction);
    
    // Do other work in the main thread

    myThread.join();

    return 0;
}

In this example, we define a function myThreadFunction() that will be executed in a separate thread. We then create a std::jthread instance myThread, passing the function as a parameter. The function will be executed concurrently once the std::jthread object is created.

Handling thread termination

A notable feature of std::jthread is that it automatically joins the thread when the std::jthread object is destroyed. This eliminates the need to manually call join() or detach() as you would with std::thread. This automatic joining ensures that the thread finishes execution before the std::jthread object goes out of scope.

void myThreadFunction() {
    // The function executed in the thread
    std::cout << "Hello from thread!\n";
}

int main() {
    {
        std::jthread myThread(myThreadFunction);
    }
    
    // Do other work in the main thread

    return 0;
}

In this example, the thread started by myThread will execute and automatically join when the std::jthread object goes out of scope at the closing brace. This guarantees that the thread completes its execution before the program terminates.

Conclusion

std::jthread is a welcome addition to C++20, providing a simpler and safer way to manage threads compared to std::thread. With automatic joining and its high-level interface, std::jthread makes it easier to write robust multithreaded applications in C++. So, if you’re starting a new project or considering migrating to C++20, give std::jthread a try!

#C++ #Threading