Passing a function as argument to other function

问题

I have been reading about this theme. I have readed a lot of possible solutions, so please, dont mark my question as duplicated, only need a puntual solution of this problem.

I have a function which calculate time of execution of some code. This code will be sent as argument (will be a function).

This is the function which calculate the time:

double executionTime( /* HERE I WANNA PASS THE FUNCTION TO CALCULATE EXECTIME*/ )
{
    LARGE_INTEGER frequency;
    LARGE_INTEGER start;
    LARGE_INTEGER end;
    double interval;

    QueryPerformanceFrequency(&frequency);
    QueryPerformanceCounter(&start);

    // HERE GOES CODE TO PROCCESS

    QueryPerformanceCounter(&end);
    interval = (double) (end.QuadPart - start.QuadPart) / frequency.QuadPart;

    return (interval);
}

I have tryed this (and another ways, but it is the most visible):

double executionTime( void (*f)() )
{
    LARGE_INTEGER frequency;
    LARGE_INTEGER start;
    LARGE_INTEGER end;
    double interval;

    QueryPerformanceFrequency(&frequency);
    QueryPerformanceCounter(&start);

    // Function to proccess
    f();

    QueryPerformanceCounter(&end);
    interval = (double) (end.QuadPart - start.QuadPart) / frequency.QuadPart;

    return (interval);
}

I do not know if arguments of function to proccess are important. In some sites said yes, in another said no. The declaration of the function that I wanna proccess is:

int readFileAndInsertRegs(char *nombreFichero, PERSONA *tablaHash[], int tam, int tipoInsertado, int tipoPruebaColision)

I have called function executionTime like:

executionTime( readFileAndInsertRegs("./files/listaActores.csv", &tablaHash, TAM_E1, NORMAL, LINEAL) );

Can anyone help me with this particular problem?

Thank you.

回答1:

usually the way to do so is to pass function arguments to the executionTime and call the function with them, i.e.

double executionTime( void (*f)(), char *arg1, PERSONE arg2[], ... )
{
    // do preamble

     f(arg1, arg2, .....);

    // finish
}

...

executionTime( &readFileAndInsertRegs, "./files/listaActores.csv", &tablaHash, TAM_E1, NORMAL, LINEAL));

here is a working example:

#include <stdio.h>

void process1(void (*f)(), int farg) {
  f(farg);
}

void f1(int arg) {
  printf("f1: %d\n", arg);
}

int main() {
  process1(&f1, 10);
  return 0;
}

and, in 'c' you do not need to declare all arguments of the function, though you can, and it is a good idea to do so. Compiler could do an additional checking then

    void process1(void (*f)(int), int farg) {

来源：https://stackoverflow.com/questions/52788554/passing-a-function-as-argument-to-other-function

标签

function

arguments