函數指針-kernel例子

示例

代碼示例

#include "stdio.h"
#include <stdlib.h>

struct nested_calls {
    int a;
    int b;
};


int sum(int * a, int * b, int c) {
    printf("*a=%d \n",*a);
    printf("*b=%d \n",*b);
    return *a + *b + c;
}

int ep_call_nested(struct nested_calls *ncalls, int max_nests,
                          int (*nproc)(int *, int *, int)) {

    int aa = 10;
    int bb = 20;
    int * a = &aa;
    int * b = &bb;

    // 10+20+30 = 60
    int sum = (*nproc)(a, b, 30);
//    printf("sum=%d \n",sum);

    return ncalls->a+ncalls->b+sum+max_nests;

}

int main() {

    struct nested_calls *ncalls = (struct nested_calls*)malloc(sizeof(struct nested_calls));
    ncalls-> a = 20;
    ncalls-> b = 30;
    int max_nests = 40;

    // 20+30+40+60
    int result = ep_call_nested(ncalls,max_nests,sum);

    // 150
    printf("result=%d \n",result);
    return 0;
}