> What does the array primitive fill the array with? If it doesn't fill it, > then what if a GC happens before we fill it? (To argue no GC can happen > requires some argument about signals not happening either.) If the array is of non-pointers, then we just allocate the space. If it is an array of pointers, then it is initalized to 0x1 (i.e., a value nonzero mod 4).