Understanding Multithreading in C++

Multithreading is a widespread programming and execution model that allows multiple threads to exist within the context of a single process. These threads share the process's resources but are able to execute independently. The threaded programming model provides developers with a useful abstraction of concurrent execution. Multithreading can be leveraged to improve the performance of computationally intensive programs.

What is a Thread?

In a simple, non-technical term, a thread is a sequence of such instructions within a program that can be executed independently of other code. For simplicity, you can think of it as a separate 'mini-program' within the main program.

Multithreading in C++

C++ does not contain built-in support for multithreaded applications. Instead, it relies on third-party libraries like POSIX threads (pthreads) and the Boost threads library. However, since the 2011 C++ standard (C++11), the language has built-in multithreading capabilities.

Here's a simple example of creating a thread in C++:

#include <iostream>
#include <thread>

void function_1() {
    std::cout << "Hello from Function 1" << std::endl;
}

int main() {
    std::thread thread_1(function_1);  // This will start function_1 concurrently.

    // Do other things...

    thread_1.join();  // This will make the main thread wait for thread_1 to finish.

    return 0;
}