Possible data race

[rzajac]

After updating to the version I get:

  ==================
  WARNING: DATA RACE
  Write at 0x00c000474220 by goroutine 33:
    github.com/wagslane/go-rabbitmq.(*Publisher).startNotifyFlowHandler()
        go/pkg/mod/github.com/wagslane/go-rabbitmq@v0.6.2/publish.go:234 +0x70

  Previous read at 0x00c000474220 by goroutine 24:
    github.com/wagslane/go-rabbitmq.NewPublisher()
        go/pkg/mod/github.com/wagslane/go-rabbitmq@v0.6.2/publish.go:167 +0x3b3
    git.vonroll-infratec.com/go/meas/pkg/queue.NewPublisher()
        ws/go/meas/pkg/queue/rab_pub.go:48 +0x604
    git.vonroll-infratec.com/go/meas/pkg/queue.(*RabbitSuite).SetupTest()
        ws/go/meas/pkg/queue/rabbit_test.go:43 +0x119
    github.com/stretchr/testify/suite.Run.func1()
        go/pkg/mod/github.com/rzajac/testify@v1.6.2-0.20200929081604-1a836a85454e/suite/suite.go:148 +0x8b4
    testing.tRunner()
        /usr/local/go/src/testing/testing.go:1193 +0x202

  Goroutine 33 (running) created at:
    github.com/wagslane/go-rabbitmq.(*Publisher).startNotifyHandlers()
        go/pkg/mod/github.com/wagslane/go-rabbitmq@v0.6.2/publish.go:229 +0x164
    github.com/wagslane/go-rabbitmq.NewPublisher.func1()
        go/pkg/mod/github.com/wagslane/go-rabbitmq@v0.6.2/publish.go:160 +0x44

  Goroutine 24 (running) created at:
    testing.(*T).Run()
        /usr/local/go/src/testing/testing.go:1238 +0x5d7
    github.com/stretchr/testify/suite.runTests()
        go/pkg/mod/github.com/rzajac/testify@v1.6.2-0.20200929081604-1a836a85454e/suite/suite.go:203 +0xf7
    github.com/stretchr/testify/suite.Run()
        go/pkg/mod/github.com/rzajac/testify@v1.6.2-0.20200929081604-1a836a85454e/suite/suite.go:176 +0x944
    git.vonroll-infratec.com/go/meas/pkg/queue.TestRabbit()
        ws/go/meas/pkg/queue/rabbit_test.go:19 +0xa4
    testing.tRunner()
        /usr/local/go/src/testing/testing.go:1193 +0x202
  ==================

in my tests.

[rzajac]

OK so I run all my tests with race detector. I was able to fix race errors by returning pointer to the Publisher:

go-rabbitmq/publish.go

Line 137 in 8970619

func NewPublisher(url string, config amqp.Config, optionFuncs ...func(*PublisherOptions)) (Publisher, <-chan Return, error) {

[wagslane]

@rzajac Would you mind opening a PR with the fix you described (assuming its the right way to fix this)

[rzajac]

@wagslane Well the fix was just a first thought. Not sure if this is the right way to do it. I can do the PR.

[cyberbeast]

Has this been fixed? I am also seeing the data race.

[wagslane]

If someone could add a test to the test suite that demonstrates the race that would help this move along. Otherwise, might be a second before I can get to it.

[pete-woods]

From a quick skim through the code, it looks like you write to the various channel handles inside mutex locks, but read from them without locking in the publishing codepath.

[wagslane]

@rzajac Can you try the latest? Should be fixed