testing: tests after a data race are marked as failed (1.9rc2)

[karalabe]

Maybe I missed this behavior until now, still it seems a bug. Opposed to Go 1.8.3 (#21338 (comment)), running a racey test suite with Go 1.9rc2 results in all tests after the racey one being marked as failed:

package main

import (
	"testing"
)

func TestPreRace(t *testing.T) {
	// Nothing to do, must succeed
}

func TestRace(t *testing.T) {
	// Blow it up
	var n int

	wait := make(chan struct{})
	go func() {
		defer close(wait)
		n++
	}()

	n++
	<-wait
}

func TestPostRace(t *testing.T) {
	// Nothing to do, must succeed
}

$ go test -v --race

=== RUN   TestPreRace
--- PASS: TestPreRace (0.00s)
=== RUN   TestRace
==================
WARNING: DATA RACE
[...]
==================
--- FAIL: TestRace (1.00s)
	testing.go:700: race detected during execution of test
=== RUN   TestPostRace
--- FAIL: TestPostRace (0.00s)

Note, TestPostRace is marked as failed.

[davecheney]

Can you please check and see if this is a regression over 1.8?

…

On Tue, Aug 8, 2017 at 6:26 PM, Péter Szilágyi ***@***.***> wrote: Maybe I missed this behavior until now, still it seems a bug. Running a racey test suite with Go 1.9rc2 results in all tests after the racey one being marked as failed: package main import ( "testing" ) func TestPreRace(t *testing.T) { // Nothing to do, must succeed } func TestRace(t *testing.T) { // Blow it up var n int wait := make(chan struct{}) go func() { defer close(wait) n++ }() n++ <-wait } func TestPostRace(t *testing.T) { // Nothing to do, must succeed } $ go test -v --race === RUN TestPreRace --- PASS: TestPreRace (0.00s) === RUN TestRace ================== WARNING: DATA RACE [...] ================== --- FAIL: TestRace (1.00s) testing.go:700: race detected during execution of test === RUN TestPostRace --- FAIL: TestPostRace (0.00s) FAIL exit status 1 FAIL github.com/ethereum/go-ethereum/racetest 1.005s Note, TestPostRace is marked as failed. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#21338>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAAcA2RTSJDilA_u6q_0QcoEEUmsqlQDks5sWBu5gaJpZM4OwZ5d> .

[dominikh]

Failing tests due to races is new in 1.9 – that it flags all following tests as failed might be a bug.

[karalabe]

@dominikh Tests always failed if a data race was detected.

@davecheney Go 1.8.3 only marks the racey test failed, not the others.

$ GOROOT=/tmp/go1.8.3 /tmp/go1.8.3/bin/go test -v --race

=== RUN   TestPreRace
--- PASS: TestPreRace (0.00s)
=== RUN   TestRace
==================
WARNING: DATA RACE
[...]
==================
--- FAIL: TestRace (0.00s)
	testing.go:610: race detected during execution of test
=== RUN   TestPostRace
--- PASS: TestPostRace (0.00s)

[dominikh]

@karalabe The commit I was thinking of is 221541e

[davecheney]

This may be a regression /cc @ianlancetaylor @broady

[mvdan]

I also saw this recently and was puzzled, but I assumed it was somehow on purpose to highlight the data race. If it was on purpose, this should be documented in the release notes. Either way, something to do for 1.9.

[ianlancetaylor]

CC @cespare

[cespare]

Yeah, unintended consequence of 221541e.

We could probably just revert for 1.9, since #19851 doesn't seem too serious, and fix it properly later. But I'll check right now to see whether the real fix is trivial.

[ianlancetaylor]

I'm testing a fix.

[gopherbot]

Change https://golang.org/cl/54050 mentions this issue: testing: don't fail all tests after racy test failure

[ianlancetaylor]

Reopening for 1.9 backport.

[gopherbot]

Change https://golang.org/cl/57151 mentions this issue: [release-branch.go1.9] testing: don't fail all tests after racy test failure