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// run
// Copyright 2021 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 (
"reflect"
"runtime"
"unsafe"
)
func k(c chan string, val string) string {
b := make([]byte, 1000)
runtime.SetFinalizer(&b[0], func(*byte) {
c <- val
})
var s string
h := (*reflect.StringHeader)(unsafe.Pointer(&s))
h.Data = uintptr(unsafe.Pointer(&b[0]))
h.Len = len(b)
return s
}
func main() {
{
c := make(chan string, 2)
m := make(map[string]int)
m[k(c, "first")] = 0
m[k(c, "second")] = 0
runtime.GC()
if s := <-c; s != "first" {
panic("map[string], second key did not retain.")
}
runtime.KeepAlive(m)
}
{
c := make(chan string, 2)
m := make(map[[2]string]int)
m[[2]string{k(c, "first")}] = 0
m[[2]string{k(c, "second")}] = 0
runtime.GC()
if s := <-c; s != "first" {
panic("map[[2]string], second key did not retain.")
}
runtime.KeepAlive(m)
}
}
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