How to schedule collection cycles for custom mark-sweep collector?

Question

I\'ve written a simple garbage collector for a Postscript virtual machine, and I\'m having difficulty designing a decent set of rules for when to do a collection (when the f

Answer 1

Here is the periodic collection strategy incorporated into the original code:

enum { PERIOD = 10 };

unsigned gballoc(mfile *mem, unsigned sz) {
    unsigned z = adrent(mem, FREE);
    unsigned e;
    static period = PERIOD;
    memcpy(&e, mem->base+z, sizeof(e));
try_again:
    while (e) {
        if (szent(mem,e) >= sz) {
            memcpy(mem->base+z, mem->base+adrent(mem,e), sizeof(unsigned));
            return e;
        }
        z = adrent(mem,e);
        memcpy(&e, mem->base+z, sizeof(e));
    }
    if (--period == 0) {
        period = PERIOD;
        collect(mem, 0);
        goto try_again;
    }
    return mtalloc(mem, 0, sz);
}