[Go] Data race of calling GetToTimeFunc of fixed timestamp data type

[7phs]

Describe the bug, including details regarding any error messages, version, and platform.

Hello,

I found a data race in databricks-sql-go. A root cause of data race is timestamp fields of arrow.FixedWidthTypes and the function GetToTimeFunc() of arrow.TimestampType.

A test to reproduce a data race:

import (
	"sync"
	"testing"

	"github.com/apache/arrow/go/v15/arrow"
)

func TestArrowDataRace(t *testing.T) {
	var (
		wg         sync.WaitGroup
		w          = make(chan bool)
		routineNum = 10
	)

	wg.Add(routineNum)
	for i := 0; i < routineNum; i++ {
		go func() {
			defer wg.Done()

			<-w

			_, _ = arrow.FixedWidthTypes.Timestamp_s.(*arrow.TimestampType).GetToTimeFunc()
		}()
	}

	close(w)

	wg.Wait()
}

A command to run this test with data race detector:

go test -race -run TestArrowDataRace .

A go version is 1.21.

The same issue is in Apache Arrow Go v12.

A root cause of data race is not initialised field loc of arrow.TimestampType. It initialised in the first call of function arrow.TimestampType :: GetZone().

Component(s)

Go