var bloc uintptr
var blocMax uintptr
var memlock mutex

type memHdr struct {
	next memHdrPtr
	size uintptr
}

var memFreelist memHdrPtr // sorted in ascending order

type memHdrPtr uintptr

func (p memHdrPtr) ptr() *memHdr   { return (*memHdr)(unsafe.Pointer(p)) }
func (p *memHdrPtr) set(x *memHdr) { *p = memHdrPtr(unsafe.Pointer(x)) }

func memAlloc(n uintptr) unsafe.Pointer {
	n = memRound(n)