if int32(overflow) == -1 {
			break
		}
		if b.overflow.CompareAndSwap(overflow, overflow+1) {
			break
		}
	}
}

// newProfBuf returns a new profiling buffer with room for
// a header of hdrsize words and a buffer of at least bufwords words.
func newProfBuf(hdrsize, bufwords, tags int) *profBuf {
	if min := 2 + hdrsize + 1; bufwords < min {
		bufwords = min
	}

func Fastrand64() uint64        { return rand() }
func Fastrandn(n uint32) uint32 { return randn(n) }

type ProfBuf profBuf

func NewProfBuf(hdrsize, bufwords, tags int) *ProfBuf {
	return (*ProfBuf)(newProfBuf(hdrsize, bufwords, tags))
}

func (p *ProfBuf) Write(tag *unsafe.Pointer, now int64, hdr []uint64, stk []uintptr) {
	(*profBuf)(p).write(tag, now, hdr, stk)
}

const (