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-rw-r--r--test/stackobj.go57
1 files changed, 57 insertions, 0 deletions
diff --git a/test/stackobj.go b/test/stackobj.go
new file mode 100644
index 0000000..b6af4bd
--- /dev/null
+++ b/test/stackobj.go
@@ -0,0 +1,57 @@
+// run
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+ "fmt"
+ "runtime"
+)
+
+type HeapObj [8]int64
+
+type StkObj struct {
+ h *HeapObj
+}
+
+var n int
+var c int = -1
+
+func gc() {
+ // encourage heap object to be collected, and have its finalizer run.
+ runtime.GC()
+ runtime.GC()
+ runtime.GC()
+ n++
+}
+
+func main() {
+ f()
+ gc() // prior to stack objects, heap object is not collected until here
+ if c < 0 {
+ panic("heap object never collected")
+ }
+ if c != 1 {
+ panic(fmt.Sprintf("expected collection at phase 1, got phase %d", c))
+ }
+}
+
+func f() {
+ var s StkObj
+ s.h = new(HeapObj)
+ runtime.SetFinalizer(s.h, func(h *HeapObj) {
+ // Remember at what phase the heap object was collected.
+ c = n
+ })
+ g(&s)
+ gc()
+}
+
+func g(s *StkObj) {
+ gc() // heap object is still live here
+ runtime.KeepAlive(s)
+ gc() // heap object should be collected here
+}