custom_transaction.c

#include <stdio.h>

typedef int (*fn)(void);

void custom_transaction(fn *dos, fn *undos, size_t n) {
    for (int i = 0; i < n; ++i) {
        if (!(dos[i])()) {
            while (--i >= 0) { undos[i](); }
            return;
        }
    }
}

int do1() { printf("do 1\n"); return 1; }
int do2() { printf("do 2\n"); return 1; }
int do3() { printf("do 3\n"); return 0; }

int undo1() { printf("undo 1\n"); return 1; }
int undo2() { printf("undo 2\n"); return 1; }
int undo3() { printf("undo 3\n"); return 1; }

int main() {
    fn dos[] = {do1, do2, do3};
    fn undos[] = {undo1, undo2, undo3};

    custom_transaction(dos, undos, 3);

    return 0;
}