Create thread via class constructor

Question

Is it possible to create a thread with a function pointer to a class constructor?

If this is possible, when how would the class destructor get called?

I have made this example of what i am looking for:

class ClassA
{
public:
    ClassA(void* argPtr)
    { ... }
};

int main(void)
{
    pthread_t thread;
    pthread_create(&thread, NULL, &ClassA(), NULL);
    return 0;
}

No, a constructor is not a function; its address cannot be taken. &ClassA() (if it even compiles) creates a temporary object and takes an address of that. — Igor Tandetnik
– Igor Tandetnik, Commented May 2, 2017 at 14:32
You can create a thread that calls a function that creates an instance of ClassA and will call its constructor. — Silveris
– Silveris, Commented May 2, 2017 at 14:36
What you can do so have a thread created in your constructor which then runs on your object - not quite the same; and can end up with other cans of worms being opened (the object isn't yet constructed!) — UKMonkey
– UKMonkey, Commented May 2, 2017 at 14:51
You may want to look up <thread>. Pthreads are for C, and don't understand C++. And in modern C++, you can call std::thread(&std::make_unique<ClassA>).detach(). Then the destructor will be called when the unique_ptr goes out of scope. — MSalters
– MSalters, Commented May 2, 2017 at 15:39

user7860670 · Accepted Answer · 2017-05-02 14:40:36Z

3

Constructors are classified as "special member functions", and it is not possible to get a pointer to constructor function because it does not have a name (note that you are using class name, not a constructor function name, to invoke it):

12.1 Constructors [class.ctor]

1 Constructors do not have names.

...

2 A constructor is used to initialize objects of its class type. Because constructors do not have names, they are never found during name lookup;

Also pthread_create takes a pointer to a regular function, not to a member function.

answered May 2, 2017 at 14:40

user7860670

37.9k4 gold badges65 silver badges96 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Create thread via class constructor

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related