lazycontainer_test.go

package common

import (
	"github.com/stretchr/testify/assert"
	"testing"

	"strconv"
	"sync"
	"sync/atomic"
	"time"
	"unsafe"
)

func TestLazyContainer(t *testing.T) {

	const entries = 100000
	const iterations = 20
	const extra = 100

	var wg sync.WaitGroup

	var containers [entries + extra]*LazyContainer

	var computations int32

	for i := 0; i < entries+extra; i++ {
		z := i
		containers[i] = NewLazyContainer(
			func() unsafe.Pointer {
				time.Sleep(5 * time.Millisecond)
				pt := strconv.Itoa(z)
				atomic.AddInt32(&computations, 1)
				return unsafe.Pointer(&pt)
			})
	}

	for i := 0; i < entries; i += 2 {
		for j := 0; j < iterations; j++ {
			wg.Add(1)
			go func(idx int) {
				assert.Equal(t, strconv.Itoa(idx), *(*string)(containers[idx].Get()))
				wg.Done()
			}(i)
		}
	}

	wg.Wait()

	assert.Equal(t, entries/2, int(computations))
}