Thread: _beginthread when function has more than one parameter

I have been testing multithreading in windows. currently the function for the begin thread takes a single argument.

I want the addem function to take more that one function but I am unsure of the proper sytax.

currently it looks like this:
(process.h etc has been include, this version works)

int addem(int);
int main() {
_beginthread((void (*)(void *))addem, 0, (void *)5000);
/* Do Other Stuff */
}
.... etc

I want addem to take two values:

int addem(int, char *);

The syntax of the _beginthread is very confusing, how do I pass two parameters to the addem function in the _beginthread? The documentation just says that the final parameter is *arglist? What is the sytax of the arglist and for that matter are any of the (void(*)(void *))'s part of some kind of function declaration?



BYron

I tried your suggestion, but struct and struct pointers cannot be converted to (void *), a least the compiler doesn't want to try and if I leave out the (void *) cast it won't link because of the struct then is an unresolved external symbol.

_beginthread looks like thsI

_beginthread(__cdecl *(void *)function_name, int, *arglist)

this is how you do it

Code:

#include <stdio.h>
#include <process.h>

typedef struct ST{ 
    int num; 
    char* buf; 
}thestruct; 

void Addem(thestruct* );

int main()
{
    thestruct st;
    st.num = 6000;
    _beginthread((void(*)(void*))Addem,0,(void*)&st);
    getchar();    // freeze program so you can see output
}

void Addem(thestruct* s)
{
    printf("%d\n",(thestruct*)(s)->num);
    _endthread();
}

>but what about the if the function has multiple arguments.
It is impossible? <

its possible, but finiky and unreliable, most of the time it won't even work.

and passing int values never seem to work.

somebody else here may have a solution but as far as i know it dosn't work well.

mainly because your trying to pass multiple values to a single void pointer, how can a pointer point to multiple values?