mirror of
https://github.com/golang/go
synced 2024-11-06 09:36:16 -07:00
59 lines
948 B
Go
59 lines
948 B
Go
|
// run
|
||
|
|
|
||
|
|
// Copyright 2019 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.
|
||
|
|
|
||
|
|
// Issue 31419: race in getitab when two goroutines try
|
||
|
|
// to do the same failed interface conversion.
|
||
|
|
|
||
|
|
package main
|
||
|
|
|
||
|
|
type T int
|
||
|
|
|
||
|
|
func (t T) M() {}
|
||
|
|
|
||
|
|
type I interface {
|
||
|
|
M()
|
||
|
|
M2()
|
||
|
|
}
|
||
|
|
|
||
|
|
var t T
|
||
|
|
var e interface{} = &t
|
||
|
|
var ok = false
|
||
|
|
var ch = make(chan int)
|
||
|
|
|
||
|
|
func main() {
|
||
|
|
_, ok = e.(I) // populate itab cache with a false result
|
||
|
|
|
||
|
|
go f() // get itab in a loop
|
||
|
|
|
||
|
|
var i I
|
||
|
|
for k := 0; k < 10000; k++ {
|
||
|
|
i, ok = e.(I) // read the cached itab
|
||
|
|
if ok {
|
||
|
|
println("iteration", k, "i =", i, "&t =", &t)
|
||
|
|
panic("conversion succeeded")
|
||
|
|
}
|
||
|
|
}
|
||
|
|
<-ch
|
||
|
|
}
|
||
|
|
|
||
|
|
func f() {
|
||
|
|
for i := 0; i < 10000; i++ {
|
||
|
|
f1()
|
||
|
|
}
|
||
|
|
ch <- 1
|
||
|
|
}
|
||
|
|
|
||
|
|
func f1() {
|
||
|
|
defer func() {
|
||
|
|
err := recover()
|
||
|
|
if err == nil {
|
||
|
|
panic("did not panic")
|
||
|
|
}
|
||
|
|
}()
|
||
|
|
i := e.(I) // triggers itab.init, for getting the panic string
|
||
|
|
_ = i
|
||
|
|
}
|