const runtime.mSpanDead

5 uses

	runtime (current package)
		mgcsweep.go#L731: 		s.state.set(mSpanDead)
		mheap.go#L360: 	mSpanDead   mSpanState = iota
		mheap.go#L1672: 	s.state.set(mSpanDead)
		mheap.go#L1726: 	span.state.set(mSpanDead)
		traceallocfree.go#L54: 		if s.state.get() == mSpanDead {