// Copyright 2017 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. // The bug happened like this: // 1) The main binary adds an itab for *json.UnsupportedValueError / error // (concrete type / interface type). This itab goes in hash bucket 0x111. // 2) The plugin adds that same itab again. That makes a cycle in the itab // chain rooted at hash bucket 0x111. // 3) The main binary then asks for the itab for *dynamodbstreamsevt.Event / // json.Unmarshaler. This itab happens to also live in bucket 0x111. // The lookup code goes into an infinite loop searching for this itab. // The code is carefully crafted so that the two itabs are both from the // same bucket, and so that the second itab doesn't exist in // the itab hashmap yet (so the entire linked list must be searched). package main import ( "encoding/json" "issue18676/dynamodbstreamsevt" "plugin" ) func main() { plugin.Open("plugin.so") var x interface{} = (*dynamodbstreamsevt.Event)(nil) if _, ok := x.(json.Unmarshaler); !ok { println("something") } }