initial import

core/syncx/lockedcalls_test.go

@@ -0,0 +1,82 @@
+package syncx
+
+import (
+	"errors"
+	"fmt"
+	"sync"
+	"testing"
+	"time"
+)
+
+func TestLockedCallDo(t *testing.T) {
+	g := NewLockedCalls()
+	v, err := g.Do("key", func() (interface{}, error) {
+		return "bar", nil
+	})
+	if got, want := fmt.Sprintf("%v (%T)", v, v), "bar (string)"; got != want {
+		t.Errorf("Do = %v; want %v", got, want)
+	}
+	if err != nil {
+		t.Errorf("Do error = %v", err)
+	}
+}
+
+func TestLockedCallDoErr(t *testing.T) {
+	g := NewLockedCalls()
+	someErr := errors.New("some error")
+	v, err := g.Do("key", func() (interface{}, error) {
+		return nil, someErr
+	})
+	if err != someErr {
+		t.Errorf("Do error = %v; want someErr", err)
+	}
+	if v != nil {
+		t.Errorf("unexpected non-nil value %#v", v)
+	}
+}
+
+func TestLockedCallDoDupSuppress(t *testing.T) {
+	g := NewLockedCalls()
+	c := make(chan string)
+	var calls int
+	fn := func() (interface{}, error) {
+		calls++
+		ret := calls
+		<-c
+		calls--
+		return ret, nil
+	}
+
+	const n = 10
+	var results []int
+	var lock sync.Mutex
+	var wg sync.WaitGroup
+	for i := 0; i < n; i++ {
+		wg.Add(1)
+		go func() {
+			v, err := g.Do("key", fn)
+			if err != nil {
+				t.Errorf("Do error: %v", err)
+			}
+
+			lock.Lock()
+			results = append(results, v.(int))
+			lock.Unlock()
+			wg.Done()
+		}()
+	}
+	time.Sleep(100 * time.Millisecond) // let goroutines above block
+	for i := 0; i < n; i++ {
+		c <- "bar"
+	}
+	wg.Wait()
+
+	lock.Lock()
+	defer lock.Unlock()
+
+	for _, item := range results {
+		if item != 1 {
+			t.Errorf("number of calls = %d; want 1", item)
+		}
+	}
+}