[SDL] Passing an integer to a thread?

[Joshua Oreman]

On 8/24/06, L-28C <leo28c at gmail.com> wrote:
> Hello everyone!
> OK, so I declared my thread function with one void* parameter, and I
> need to pass an int parameter...  How do I convert void* to int?  Thanks!

A few ways.

One: void *foo_as_ptr = (void *)(long)foo_as_int;
        int foo_as_int = (long)foo_as_ptr;

Two: if it's a global or a static, just pass its address
(&foo_as_int), and in your thread function have something like
void foo_thread (void *argp) {
    int arg = *(int *)argp;
    /* ... */
}

Three: malloc() a bit of memory for it:
    int *foop = malloc (sizeof(int));
    *foop = foo_int;
    /* create your thread with foop as an arg */
/* ... */
void foo_thread (void *argp) {
    int arg = *(int *)argp;
    free (argp);
    /* ... */
}

Which way is up to you.  The first is certainly the easiest; however,
it won't work on systems with smaller pointers than ints, and it'll
generate warnings on systems with different-sized pointers than longs.
 Option 2 works if it's a global or a static.  Option 3 works for
anything, but is certainly a bit cumbersome.

-- Josh

>
> --
> ~ Leo, M@$73r L3170, Sulfurik, Kixdemp, L-28C... Whatever you wanna call me.
>
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