}

	tid := int(gp.lockedm.ptr().procid)
	if tid == 0 {
		return nil, plainError("missing tid")
	}

	f := efaceOf(&fn)
	if f._type == nil || f._type.Kind_&abi.KindMask != abi.Func {
		return nil, plainError("fn must be a function")
	}
	fv := (*funcval)(f.data)

	a := efaceOf(&stackArgs)
	if a._type != nil && a._type.Kind_&abi.KindMask != abi.Pointer {
		return nil, plainError("args must be a pointer or nil")
	}

	deep interface{} = [1]struct{ a *[2]byte }{{a: &[2]byte{'z', 'w'}}}
	ch   interface{} = make(chan bool, 1)
)

func main() {
	var fail bool
	for i, test := range efaces {
		s := fmt.Sprintf("%[1]T %[1]v", test.x)
		if s != test.s {
			fmt.Printf("eface(%d)=%q want %q\n", i, s, test.s)
			fail = true
		}
	}

	for i, test := range ifaces {
		s := fmt.Sprintf("%[1]T %#[1]v %[1]s", test.x)
		if s != test.s {

Matthew Dempsky <******@****.***> 1646087539 -0800

import (
	"sync/atomic"
	"unsafe"
)

var one interface{} = 1

type eface struct {
	typ  unsafe.Pointer
	data unsafe.Pointer
}

func f(c chan struct{}) {
	var x atomic.Value

	go func() {
		x.Swap(one) // writing using the old marker
	}()
	for i := 0; i < 100000; i++ {
		v := x.Load() // reading using the new marker

		p := (*eface)(unsafe.Pointer(&v)).typ
		if uintptr(p) == ^uintptr(0) {

	// otherwise. A slot is still in use until *both* the tail
	// index has moved beyond it and typ has been set to nil. This
	// is set to nil atomically by the consumer and read
	// atomically by the producer.
	vals []eface
}

type eface struct {
	typ, val unsafe.Pointer
}

const dequeueBits = 32

// dequeueLimit is the maximum size of a poolDequeue.
//
// This must be at most (1<<dequeueBits)/2 because detecting fullness

	verifyGCInfo(t, "bss BigStruct", &bssBigStruct, infoBigStruct())
	verifyGCInfo(t, "bss string", &bssString, infoString)
	verifyGCInfo(t, "bss slice", &bssSlice, infoSlice)
	verifyGCInfo(t, "bss eface", &bssEface, infoEface)
	verifyGCInfo(t, "bss iface", &bssIface, infoIface)

	verifyGCInfo(t, "data Ptr", &dataPtr, infoPtr)
	verifyGCInfo(t, "data ScalarPtr", &dataScalarPtr, infoScalarPtr)

func TestEmbeddedMethod(t *testing.T) {
	const src = `package p; type I interface { error }`
	pkg := mustTypecheck(src, nil, nil)

	// get original error.Error method
	eface := Universe.Lookup("error")
	orig, _, _ := LookupFieldOrMethod(eface.Type(), false, nil, "Error")
	if orig == nil {
		t.Fatalf("original error.Error not found")
	}

	// get embedded error.Error method
	iface := pkg.Scope().Lookup("I")

// poolDequeue testing.
type PoolDequeue interface {
	PushHead(val any) bool
	PopHead() (any, bool)
	PopTail() (any, bool)
}

func NewPoolDequeue(n int) PoolDequeue {
	d := &poolDequeue{
		vals: make([]eface, n),
	}
	// For testing purposes, set the head and tail indexes close
	// to wrapping around.
	d.headTail.Store(d.pack(1<<dequeueBits-500, 1<<dequeueBits-500))
	return d
}

func TestEmbeddedMethod(t *testing.T) {
	const src = `package p; type I interface { error }`
	pkg := mustTypecheck(src, nil, nil)

	// get original error.Error method
	eface := Universe.Lookup("error")
	orig, _, _ := LookupFieldOrMethod(eface.Type(), false, nil, "Error")
	if orig == nil {
		t.Fatalf("original error.Error not found")
	}

	// get embedded error.Error method
	iface := pkg.Scope().Lookup("I")

	{"runtime.panicdottypeE", 1},
	{"runtime.panicdottypeI", 1},
	{"runtime.panicnildottype", 1},
	{"runtime.typeAssert", 1},
	{"runtime.interfaceSwitch", 1},
	{"runtime.ifaceeq", 1},
	{"runtime.efaceeq", 1},
	{"runtime.panicrangestate", 1},
	{"runtime.deferrangefunc", 1},
	{"runtime.rand32", 1},
	{"runtime.makemap64", 1},
	{"runtime.makemap", 1},
	{"runtime.makemap_small", 1},
	{"runtime.mapaccess1", 1},