go - 无法理解go test -race:RACE:数据警告堆栈跟踪

在测试我的项目时，我遇到了DATA RACE警告，想知道是否有人会帮助我解决问题。过去，我从未尝试过测试go例程，并且发现很难将自己的头放在数据争用上。

我在说明中提供了指向未解决问题的链接，并在问题说明中提供了跟踪信息。

我真的很希望能从将来学习调试类似问题和为go例程编写更好的测试方面提供一些帮助。

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

下方也提供了该跟踪的摘要

=== 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

最佳答案

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都在同一位置读取和写入。如果查看错误所指向的行:

goroutine 8 上的116:

if t.status != models.AttackResponseStatusRunning {

goroutine 7 上的107:

t.status = models.AttackResponseStatusRunning

您可以看到，goroutine正在访问task的状态而没有任何同步，并且，正如您已经知道的那样，这可能会导致竞争状态。

因此，如果您的程序允许多个goroutine访问单个任务，则需要通过使用互斥锁来确保不会发生数据争用。