Just remove the `static` keyword and there you go.
But it's an "optimization", and avoiding previously attempted methods is the whole point of the trick. Otherwise it would be an easy and uninteresting function.
> Just remove the `static` keyword and there you go.
That‘ll probably try all methods on every single file that is processed, so if method #16 is the one that works, you get 15 unnecessary syscalls for every file.
Lets say that there are only 3 methods and method #2 is the one that works initially. On the first call it'll try #1 and when that doesn't work it'll try #2 which will be successful. For the next however many calls it'll jump straight to #2. If #2 starts returning ENOSYS at some point it'll try #3 and if that works then all future calls will jump straight to #3. However if #3 stops working then it will keep on failing until #3 starts working again even if #1 started working after the first call.
I think (I haven't actually tested it) you can do what the parent commenter wants by wrapping the whole thing in a do-loop but the original implementation is questionable enough, sticking an extra loop in there isn't doing anything to help make it less horrible.
int set_the_mtime(...) {
static int switch_step = 0;
int loop_again = 1;
do {
switch (switch_step) {
case 0:
if (method_0_works(...))
return 0;
switch_step++;
/* FALLTHROUGH */
case 1:
if (method_1_works(...))
return 0;
switch_step++;
/* FALLTHROUGH */
case 2:
if (method_2_works(...))
return 0;
}
switch_step = 0;
} while (loop_again--);
return -1; /* ultimate failure */
}
But it's an "optimization", and avoiding previously attempted methods is the whole point of the trick. Otherwise it would be an easy and uninteresting function.