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-rw-r--r--test/fixedbugs/issue15277.go40
1 files changed, 40 insertions, 0 deletions
diff --git a/test/fixedbugs/issue15277.go b/test/fixedbugs/issue15277.go
new file mode 100644
index 0000000..af165f7
--- /dev/null
+++ b/test/fixedbugs/issue15277.go
@@ -0,0 +1,40 @@
+// run
+
+// Copyright 2016 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.
+// +build amd64
+
+package main
+
+import "runtime"
+
+type big [10 << 20]byte
+
+func f(x *big, start int64) {
+ if delta := inuse() - start; delta < 9<<20 {
+ println("after alloc: expected delta at least 9MB, got: ", delta)
+ }
+ runtime.KeepAlive(x)
+ x = nil
+ if delta := inuse() - start; delta > 1<<20 {
+ println("after drop: expected delta below 1MB, got: ", delta)
+ }
+ x = new(big)
+ if delta := inuse() - start; delta < 9<<20 {
+ println("second alloc: expected delta at least 9MB, got: ", delta)
+ }
+ runtime.KeepAlive(x)
+}
+
+func main() {
+ x := inuse()
+ f(new(big), x)
+}
+
+func inuse() int64 {
+ runtime.GC()
+ var st runtime.MemStats
+ runtime.ReadMemStats(&st)
+ return int64(st.Alloc)
+}