无法理解 go test -race : RACE: DATA WARNING 堆栈跟踪

Question

我在测试我的项目时运行遇到了 DATA RACE 警告，想知道是否有人愿意帮助我解决这个问题。我过去从未尝试过测试 go 例程，我发现很难解决数据竞争问题。

我在未解决问题的描述中提供了 link，问题描述中有跟踪。

我真的很感激一些帮助，只是从学习调试类似问题和将来为 go 例程编写更好的测试方面。

https://github.com/nitishm/vegeta-server/issues/52

下面还提供了一段跟踪记录

=== RUN   Test_dispatcher_Cancel_Error_completed
INFO[0000] creating new dispatcher                       component=dispatcher
INFO[0000] starting dispatcher                           component=dispatcher
INFO[0000] dispatching new attack                        ID=d63a79ac-6f51-486e-845d-077c8c76168a Status=scheduled component=dispatcher
==================
WARNING: DATA RACE
Read at 0x00c0000f8d68 by goroutine 8:
  vegeta-server/internal/dispatcher.(*task).Complete()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:116 +0x61
  vegeta-server/internal/dispatcher.run()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:213 +0x17a

Previous write at 0x00c0000f8d68 by goroutine 7:
  vegeta-server/internal/dispatcher.(*task).Run()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:107 +0x12a
  vegeta-server/internal/dispatcher.(*dispatcher).Run()
      /Users/nitishm/vegeta-server/internal/dispatcher/dispatcher.go:109 +0xb5f

Goroutine 8 (running) created at:
  vegeta-server/internal/dispatcher.(*task).Run()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:105 +0x11c
  vegeta-server/internal/dispatcher.(*dispatcher).Run()
      /Users/nitishm/vegeta-server/internal/dispatcher/dispatcher.go:109 +0xb5f

Goroutine 7 (running) created at:
  vegeta-server/internal/dispatcher.Test_dispatcher_Cancel_Error_completed()
      /Users/nitishm/vegeta-server/internal/dispatcher/dispatcher_test.go:249 +0x545
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:827 +0x162
==================
==================
WARNING: DATA RACE
Write at 0x00c0000f8d98 by goroutine 8:
  vegeta-server/internal/dispatcher.(*task).SendUpdate()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:164 +0x70
  vegeta-server/internal/dispatcher.(*task).Complete()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:128 +0x20e
  vegeta-server/internal/dispatcher.run()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:213 +0x17a

Previous write at 0x00c0000f8d98 by goroutine 7:
  vegeta-server/internal/dispatcher.(*task).SendUpdate()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:164 +0x70
  vegeta-server/internal/dispatcher.(*task).Run()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:109 +0x15d
  vegeta-server/internal/dispatcher.(*dispatcher).Run()
      /Users/nitishm/vegeta-server/internal/dispatcher/dispatcher.go:109 +0xb5f

Goroutine 8 (running) created at:
  vegeta-server/internal/dispatcher.(*task).Run()
      /Users/nitishm/vegeta-server/internal/dispatcher/task.go:105 +0x11c
  vegeta-server/internal/dispatcher.(*dispatcher).Run()
      /Users/nitishm/vegeta-server/internal/dispatcher/dispatcher.go:109 +0xb5f

Goroutine 7 (running) created at:
  vegeta-server/internal/dispatcher.Test_dispatcher_Cancel_Error_completed()
      /Users/nitishm/vegeta-server/internal/dispatcher/dispatcher_test.go:249 +0x545
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:827 +0x162
==================
INFO[0002] canceling attack                              ID=d63a79ac-6f51-486e-845d-077c8c76168a ToCancel=true component=dispatcher
ERRO[0002] failed to cancel task                         ID=d63a79ac-6f51-486e-845d-077c8c76168a ToCancel=true component=dispatcher error="cannot cancel task d63a79ac-6f51-486e-845d-077c8c76168a with status completed"
WARN[0002] gracefully shutting down the dispatcher       component=dispatcher
--- FAIL: Test_dispatcher_Cancel_Error_completed (2.01s)
    testing.go:771: race detected during execution of test

Answer 1

据我了解：

Read at 0x00c0000f8d68 by goroutine 8: 和 Previous write at 0x00c0000f8d68 by goroutine 7

意味着 goroutines 8 和 7 正在读取和写入相同的位置。如果您查看错误指向的行：

goroutine 8 在 116:

if t.status != models.AttackResponseStatusRunning {

goroutine 7 在 107:

t.status = models.AttackResponseStatusRunning

您可以看到 goroutines 在没有任何同步的情况下访问 task 的状态，正如您已经知道的那样，这可能会导致竞争条件。

因此，如果您的程序允许多个 goroutine 访问单个任务，您需要确保不会发生数据竞争，例如使用互斥锁。

无法理解 go test -race : RACE: DATA WARNING 堆栈跟踪

Cannot understand go test -race : RACE: DATA WARNING stack trace

go

testing

race-condition

goroutine

data-race