How to easily make std::cout thread-safe?

Question

I have a multi-threaded application, which heavily uses std::cout for logging without any locking. In such a case, how can I easily add lock mechanism to make <

Answer 1

I know its an old question, but it helped me a lot with my problem. I created an utility class based on this post answers and I'd like to share my result.

Considering we use C++11 or latter C++ versions, this class provides print and println functions to compose strings before calling the standard output stream and avoid concurrency problems. These are variadic functions which use templates to print different data types.

You can check its use in a producer-consumer problem on my github: https://github.com/eloiluiz/threadsBar

So, here is my code:

class Console {
private:
    Console() = default;

    inline static void innerPrint(std::ostream &stream) {}

    template
    inline static void innerPrint(std::ostream &stream, Head const head, Tail const ...tail) {
        stream << head;
        innerPrint(stream, tail...);
    }

public:
    template
    inline static void print(Head const head, Tail const ...tail) {
        // Create a stream buffer
        std::stringbuf buffer;
        std::ostream stream(&buffer);
        // Feed input parameters to the stream object
        innerPrint(stream, head, tail...);
        // Print into console and flush
        std::cout << buffer.str();
    }

    template
    inline static void println(Head const head, Tail const ...tail) {
        print(head, tail..., "\n");
    }
};