MemMapFS: race condition when creating directories #298
Description
When trying to create a same folder concurrently, one Mkdir should return an error stating the path already exists. MemMapFS works a lot of the time as expected but sometimes the error is not returned.
See below, a test case to reproduce the problem:
import (
"github.com/spf13/afero"
"github.com/stretchr/testify/require"
"testing"
)
func TestMemMap(t *testing.T) {
for i := 0; i < 100; i++ {
fs := afero.NewMemMapFs()
dir := "testDir"
c1 := make(chan error)
c2 := make(chan error)
go func() {
c1 <- fs.Mkdir(dir, 0755)
}()
go func() {
c2 <- fs.Mkdir(dir, 0755)
}()
// Only one attempt of creating the directory should succeed.
err1 := <-c1
err2 := <-c2
require.NotEqual(t, err1, err2, "run #%v", i)
}
}
The failure can happen at any time
e.g.
=== RUN TestMemMap
TestMemMap: test_test.go:27:
Error Trace: test_test.go:27
Error: Should not be: <nil>
Test: TestMemMap
Messages: run #17
--- FAIL: TestMemMap (0.00s)