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-rw-r--r--test/gcstring.go48
1 files changed, 48 insertions, 0 deletions
diff --git a/test/gcstring.go b/test/gcstring.go
new file mode 100644
index 0000000..7633d5d
--- /dev/null
+++ b/test/gcstring.go
@@ -0,0 +1,48 @@
+// run
+
+// Copyright 2014 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.
+
+// Test that s[len(s):] - which can point past the end of the allocated block -
+// does not confuse the garbage collector.
+
+package main
+
+import (
+ "runtime"
+ "time"
+)
+
+type T struct {
+ ptr **int
+ pad [120]byte
+}
+
+var things []interface{}
+
+func main() {
+ setup()
+ runtime.GC()
+ runtime.GC()
+ time.Sleep(10*time.Millisecond)
+ runtime.GC()
+ runtime.GC()
+ time.Sleep(10*time.Millisecond)
+}
+
+func setup() {
+ var Ts []interface{}
+ buf := make([]byte, 128)
+
+ for i := 0; i < 10000; i++ {
+ s := string(buf)
+ t := &T{ptr: new(*int)}
+ runtime.SetFinalizer(t.ptr, func(**int) { panic("*int freed too early") })
+ Ts = append(Ts, t)
+ things = append(things, s[len(s):])
+ }
+
+ things = append(things, Ts...)
+}
+