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package lb
import (
"context"
"reflect"
"sync"
"sync/atomic"
"testing"
"time"
"github.com/go-kit/kit/endpoint"
"github.com/go-kit/kit/sd"
)
func TestRoundRobin(t *testing.T) {
var (
counts = []int{0, 0, 0}
endpoints = []endpoint.Endpoint{
func(context.Context, interface{}) (interface{}, error) { counts[0]++; return struct{}{}, nil },
func(context.Context, interface{}) (interface{}, error) { counts[1]++; return struct{}{}, nil },
func(context.Context, interface{}) (interface{}, error) { counts[2]++; return struct{}{}, nil },
}
)
endpointer := sd.FixedEndpointer(endpoints)
balancer := NewRoundRobin(endpointer)
for i, want := range [][]int{
{1, 0, 0},
{1, 1, 0},
{1, 1, 1},
{2, 1, 1},
{2, 2, 1},
{2, 2, 2},
{3, 2, 2},
} {
endpoint, err := balancer.Endpoint()
if err != nil {
t.Fatal(err)
}
endpoint(context.Background(), struct{}{})
if have := counts; !reflect.DeepEqual(want, have) {
t.Fatalf("%d: want %v, have %v", i, want, have)
}
}
}
func TestRoundRobinNoEndpoints(t *testing.T) {
endpointer := sd.FixedEndpointer{}
balancer := NewRoundRobin(endpointer)
_, err := balancer.Endpoint()
if want, have := ErrNoEndpoints, err; want != have {
t.Errorf("want %v, have %v", want, have)
}
}
func TestRoundRobinNoRace(t *testing.T) {
balancer := NewRoundRobin(sd.FixedEndpointer([]endpoint.Endpoint{
endpoint.Nop,
endpoint.Nop,
endpoint.Nop,
endpoint.Nop,
endpoint.Nop,
}))
var (
n = 100
done = make(chan struct{})
wg sync.WaitGroup
count uint64
)
wg.Add(n)
for i := 0; i < n; i++ {
go func() {
defer wg.Done()
for {
select {
case <-done:
return
default:
_, _ = balancer.Endpoint()
atomic.AddUint64(&count, 1)
}
}
}()
}
time.Sleep(time.Second)
close(done)
wg.Wait()
t.Logf("made %d calls", atomic.LoadUint64(&count))
}
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