1 files changed, 14 insertions, 17 deletions
diff --git a/src/runtime/lfstack_test.go b/src/runtime/lfstack_test.go
index d0a1b6ba06..e36297e541 100644
--- a/src/runtime/lfstack_test.go
+++ b/src/runtime/lfstack_test.go
@@ -16,6 +16,17 @@ type MyNode struct {
 	data int
 }
 
+// allocMyNode allocates nodes that are stored in an lfstack
+// outside the Go heap.
+// We require lfstack objects to live outside the heap so that
+// checkptr passes on the unsafe shenanigans used.
+func allocMyNode(data int) *MyNode {
+	n := (*MyNode)(PersistentAlloc(unsafe.Sizeof(MyNode{})))
+	LFNodeValidate(&n.LFNode)
+	n.data = data
+	return n
+}
+
 func fromMyNode(node *MyNode) *LFNode {
 	return (*LFNode)(unsafe.Pointer(node))
 }
@@ -30,22 +41,17 @@ func TestLFStack(t *testing.T) {
 	stack := new(uint64)
 	global = stack // force heap allocation
 
-	// Need to keep additional references to nodes, the stack is not all that type-safe.
-	var nodes []*MyNode
-
 	// Check the stack is initially empty.
 	if LFStackPop(stack) != nil {
 		t.Fatalf("stack is not empty")
 	}
 
 	// Push one element.
-	node := &MyNode{data: 42}
-	nodes = append(nodes, node)
+	node := allocMyNode(42)
 	LFStackPush(stack, fromMyNode(node))
 
 	// Push another.
-	node = &MyNode{data: 43}
-	nodes = append(nodes, node)
+	node = allocMyNode(43)
 	LFStackPush(stack, fromMyNode(node))
 
 	// Pop one element.
@@ -75,8 +81,6 @@ func TestLFStack(t *testing.T) {
 	}
 }
 
-var stress []*MyNode
-
 func TestLFStackStress(t *testing.T) {
 	const K = 100
 	P := 4 * GOMAXPROCS(-1)
@@ -86,15 +90,11 @@ func TestLFStackStress(t *testing.T) {
 	}
 	// Create 2 stacks.
 	stacks := [2]*uint64{new(uint64), new(uint64)}
-	// Need to keep additional references to nodes,
-	// the lock-free stack is not type-safe.
-	stress = nil
 	// Push K elements randomly onto the stacks.
 	sum := 0
 	for i := 0; i < K; i++ {
 		sum += i
-		node := &MyNode{data: i}
-		stress = append(stress, node)
+		node := allocMyNode(i)
 		LFStackPush(stacks[i%2], fromMyNode(node))
 	}
 	c := make(chan bool, P)
@@ -134,7 +134,4 @@ func TestLFStackStress(t *testing.T) {
 	if sum2 != sum {
 		t.Fatalf("Wrong sum %d/%d", sum2, sum)
 	}
-
-	// Let nodes be collected now.
-	stress = nil
 }