golang issue52612 代码
文件路径：/test/fixedbugs/issue52612.go
/ run
/ Copyright 2022 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 (
"sync/atomic"
"unsafe"
)
var one interface{} = 1
type eface struct {
typ unsafe.Pointer
data unsafe.Pointer
}
func f(c chan struct{}) {
var x atomic.Value
go func() {
x.Swap(one) / writing using the old marker
}()
for i := 0; i < 100000; i++ {
v := x.Load() / reading using the new marker
p := (*eface)(unsafe.Pointer(&v)).typ
if uintptr(p) == ^uintptr(0) {
/ We read the old marker, which the new reader
/ doesn't know is a case where it should retry
/ instead of returning it.
panic("bad typ field")
}
}
c <- struct{}{}
}
func main() {
c := make(chan struct{}, 10)
for i := 0; i < 10; i++ {
go f(c)
}
for i := 0; i < 10; i++ {
<-c
}
}