Ch. 5 Race condition in counter.go

[crbrox]

I think that calling updater.Reset at https://github.com/matryer/goblueprints/blob/master/chapter5/counter/main.go#L98
causes a race condition

(the other access is at https://github.com/matryer/goblueprints/blob/master/chapter5/counter/main.go#L76)

[matryer]

That's an interesting one. Are you sure it causes a race condition?

[crbrox]

I think so ...

With build -race, this stack is displayed when counter is executed

2015/04/20 11:26:03 Finished updating database...
==================
WARNING: DATA RACE
Read by goroutine 23:
  main.func·004()
      /Users/brox/GoPath/src/github.com/matryer/goblueprints/chapter5/counter/main.go:98 +0x1f4

Previous write by main goroutine:
  main.main()
      /Users/brox/GoPath/src/github.com/matryer/goblueprints/chapter5/counter/main.go:99 +0xb3e

Goroutine 23 (running) created at:
  time.goFunc()
      /usr/local/go/src/time/sleep.go:129 +0x59
==================
2015/04/20 11:26:04 Updating database...

[...]

2015/04/20 11:29:19 INF    1 [votes/counter] stopping handlers
2015/04/20 11:29:19 INF    1 [votes/counter] exiting lookupdLoop
2015/04/20 11:29:19 INF    1 [votes/counter] rdyLoop exiting
2015/04/20 11:29:19 Closing database connection...
Found 1 data race(s)

[matryer]

That's very interesting - thanks.