race condition error on batcher

[peczenyj]

Hello

we discover a possible race condition on batcher since version go-resiliency 1.4 and 1.5

Here is a minimal example with a test that trigger this issue

I tested with latest go (1.22) and go-resiliency 1.5

source code is available here https://github.com/peczenyj/example-race

package: https://github.com/peczenyj/example-race/blob/main/foo/foo.go

test: https://github.com/peczenyj/example-race/blob/main/foo/foo_test.go

$ go test -race ./foo/...
==================
WARNING: DATA RACE
Write at 0x00c00009eec8 by goroutine 7:
  github.com/eapache/go-resiliency/batcher.(*Batcher).submitWork()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/vendor/github.com/eapache/go-resiliency/batcher/batcher.go:74 +0xed
  github.com/eapache/go-resiliency/batcher.(*Batcher).Run()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/vendor/github.com/eapache/go-resiliency/batcher/batcher.go:55 +0x20e
  github.com/peczenyj/example-race/foo.(*Foo).Get()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/foo/foo.go:36 +0x2e7
  github.com/peczenyj/example-race/foo_test.TestBatcher()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/foo/foo_test.go:23 +0x2e8
  testing.tRunner()
      /usr/local/go1.22.0/src/testing/testing.go:1689 +0x21e
  testing.(*T).Run.gowrap1()
      /usr/local/go1.22.0/src/testing/testing.go:1742 +0x44

Previous read at 0x00c00009eec8 by goroutine 8:
  github.com/eapache/go-resiliency/batcher.(*Batcher).batch()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/vendor/github.com/eapache/go-resiliency/batcher/batcher.go:100 +0x3d8
  github.com/eapache/go-resiliency/batcher.(*Batcher).submitWork.gowrap2()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/vendor/github.com/eapache/go-resiliency/batcher/batcher.go:76 +0x33

Goroutine 7 (running) created at:
  testing.(*T).Run()
      /usr/local/go1.22.0/src/testing/testing.go:1742 +0x825
  testing.runTests.func1()
      /usr/local/go1.22.0/src/testing/testing.go:2161 +0x85
  testing.tRunner()
      /usr/local/go1.22.0/src/testing/testing.go:1689 +0x21e
  testing.runTests()
      /usr/local/go1.22.0/src/testing/testing.go:2159 +0x8be
  testing.(*M).Run()
      /usr/local/go1.22.0/src/testing/testing.go:2027 +0xf17
  main.main()
      _testmain.go:49 +0x2bd

Goroutine 8 (finished) created at:
  github.com/eapache/go-resiliency/batcher.(*Batcher).submitWork()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/vendor/github.com/eapache/go-resiliency/batcher/batcher.go:76 +0x1ef
  github.com/eapache/go-resiliency/batcher.(*Batcher).Run()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/vendor/github.com/eapache/go-resiliency/batcher/batcher.go:55 +0x20e
  github.com/peczenyj/example-race/foo.(*Foo).Get()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/foo/foo.go:36 +0x283
  github.com/peczenyj/example-race/foo_test.TestBatcher()
      /home/weborama.office/tiago/work/go/src/github.com/peczenyj/example-race/foo/foo_test.go:22 +0x284
  testing.tRunner()
      /usr/local/go1.22.0/src/testing/testing.go:1689 +0x21e
  testing.(*T).Run.gowrap1()
      /usr/local/go1.22.0/src/testing/testing.go:1742 +0x44
==================
--- FAIL: TestBatcher (2.01s)
    testing.go:1398: race detected during execution of test
FAIL
FAIL	github.com/peczenyj/example-race/foo	2.017s
FAIL

while using go-resiliency 1.3 there is no race

$ go test -race ./foo/...
ok  	github.com/peczenyj/example-race/foo	3.016s

regards

[eapache]

Thanks for the report, I made a few other small improvements while I was cleaning this up!