From 1a9f27d5034056c1adf53a39939973c4495370f4 Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Wed, 3 Jan 2018 17:50:47 -0800 Subject: encoding/gob: avoid race on idToType Fixes #23328 Change-Id: Ie4864d7f388d363860318fe41431d8a9719e9a75 Reviewed-on: https://go-review.googlesource.com/86075 Run-TryBot: Ian Lance Taylor Reviewed-by: Brad Fitzpatrick Reviewed-by: Rob Pike TryBot-Result: Gobot Gobot --- src/cmd/dist/test.go | 2 +- src/encoding/gob/decode.go | 2 ++ src/encoding/gob/type_test.go | 42 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 45 insertions(+), 1 deletion(-) diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go index 5842a98233..44971ecf17 100644 --- a/src/cmd/dist/test.go +++ b/src/cmd/dist/test.go @@ -1286,7 +1286,7 @@ func (t *tester) runFlag(rx string) string { func (t *tester) raceTest(dt *distTest) error { t.addCmd(dt, "src", t.goTest(), "-race", "-i", "runtime/race", "flag", "os", "os/exec") t.addCmd(dt, "src", t.goTest(), "-race", t.runFlag("Output"), "runtime/race") - t.addCmd(dt, "src", t.goTest(), "-race", t.runFlag("TestParse|TestEcho|TestStdinCloseRace|TestClosedPipeRace"), "flag", "os", "os/exec") + t.addCmd(dt, "src", t.goTest(), "-race", t.runFlag("TestParse|TestEcho|TestStdinCloseRace|TestClosedPipeRace|TestTypeRace"), "flag", "os", "os/exec", "encoding/gob") // We don't want the following line, because it // slows down all.bash (by 10 seconds on my laptop). // The race builder should catch any error here, but doesn't. diff --git a/src/encoding/gob/decode.go b/src/encoding/gob/decode.go index 8dece42e90..2da913fceb 100644 --- a/src/encoding/gob/decode.go +++ b/src/encoding/gob/decode.go @@ -1038,6 +1038,8 @@ func (dec *Decoder) compatibleType(fr reflect.Type, fw typeId, inProgress map[re // typeString returns a human-readable description of the type identified by remoteId. func (dec *Decoder) typeString(remoteId typeId) string { + typeLock.Lock() + defer typeLock.Unlock() if t := idToType[remoteId]; t != nil { // globally known type. return t.string() diff --git a/src/encoding/gob/type_test.go b/src/encoding/gob/type_test.go index 14f25d8ac4..934270eedd 100644 --- a/src/encoding/gob/type_test.go +++ b/src/encoding/gob/type_test.go @@ -7,6 +7,7 @@ package gob import ( "bytes" "reflect" + "sync" "testing" ) @@ -218,3 +219,44 @@ func TestStressParallel(t *testing.T) { <-c } } + +// Issue 23328. Note that this test name is known to cmd/dist/test.go. +func TestTypeRace(t *testing.T) { + c := make(chan bool) + var wg sync.WaitGroup + for i := 0; i < 2; i++ { + wg.Add(1) + go func(i int) { + defer wg.Done() + var buf bytes.Buffer + enc := NewEncoder(&buf) + dec := NewDecoder(&buf) + var x interface{} + switch i { + case 0: + x = &N1{} + case 1: + x = &N2{} + default: + t.Errorf("bad i %d", i) + return + } + m := make(map[string]string) + <-c + if err := enc.Encode(x); err != nil { + t.Error(err) + return + } + if err := enc.Encode(x); err != nil { + t.Error(err) + return + } + if err := dec.Decode(&m); err == nil { + t.Error("decode unexpectedly succeeded") + return + } + }(i) + } + close(c) + wg.Wait() +} -- cgit v1.2.3-54-g00ecf