I have an object of class AI
, which has a private non static void function which has a lot of arguments: minmax(double& val,double alpha, double beta, unsigned short depth, board* thisTurn)
; because this is a very time intensive function I want to use a number of threads to run it concurrently, therefor I must create a thread with this function inside another function inside the AI class;
According toThis question to make threads inside member functions containing non static member functions wiht no arguments of said class, one must call:
std::thread t(&myclass::myfunc,this);
And according to this tutorial threads of fucntions with multiple arguments can be created as such:
std::thread t(foo,4,5)
where the function 'foo' has 2 integer arguments
However I desire to mix these to things, to call a function which has arguments, which is also a non static member function, from inside the class that it is a member of, and i am not sure how to mix these to things.
I have off course tried (remember that it is inside a function inside the AI class):
std::thread t(&AI::minmax,val,alpha,beta,depth,thisTurn,this);
and
std::thread t(&AI::minmax,this,val,alpha,beta,depth,thisTurn);
But both cases fails with a compile error like this:
error: no matching constructor for initialization of 'std::thread'
candidate constructor template not viable: requires single argument '__f', but
7 arguments were provided
My question is therefor, if or if not, it is even possiple to -- from inside a member function of a class -- call a non static member function which has several arguments as a thread, and if this is the case, how it is done.
This question is however not wether or not it is a good idea to use multithreading in my specific case.
After doing some testing i realized that i can not call functions with arguments as threads at all, not even non-member functions with only one argument called directly from main, this was however solved by asking this other question where i realized that i simply need to add the flag -std=c++11 (because apparantly macs don't always use all c++11 features as standard) after doing so the answer works fine.
You need to wrap references using std::ref
. The following example compiles fine:
#include <iostream>
#include <thread>
class board;
class AI
{
public:
void minmax(double& val, double alpha, double beta, unsigned short depth, board* thisTurn)
{
std::cout << "minmax" << std::endl;
}
void spawnThread()
{
double val;
double alpha;
double beta;
unsigned short depth;
board* thisTurn;
std::thread t(&AI::minmax, this, std::ref(val), alpha, beta, depth, thisTurn);
t.join();
}
};
int main()
{
AI ai;
ai.spawnThread();
}