86 lines
1.8 KiB
Go
86 lines
1.8 KiB
Go
|
/*
|
||
|
|
Copyright 2012 Google Inc.
|
||
|
|
|
||
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
||
|
|
you may not use this file except in compliance with the License.
|
||
|
|
You may obtain a copy of the License at
|
||
|
|
|
||
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
|
||
|
|
Unless required by applicable law or agreed to in writing, software
|
||
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
||
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||
|
|
See the License for the specific language governing permissions and
|
||
|
|
limitations under the License.
|
||
|
|
*/
|
||
|
|
|
||
|
|
package singleflight
|
||
|
|
|
||
|
|
import (
|
||
|
|
"errors"
|
||
|
|
"fmt"
|
||
|
|
"sync"
|
||
|
|
"sync/atomic"
|
||
|
|
"testing"
|
||
|
|
"time"
|
||
|
|
)
|
||
|
|
|
||
|
|
func TestDo(t *testing.T) {
|
||
|
|
var g Group
|
||
|
|
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 TestDoErr(t *testing.T) {
|
||
|
|
var g Group
|
||
|
|
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 TestDoDupSuppress(t *testing.T) {
|
||
|
|
var g Group
|
||
|
|
c := make(chan string)
|
||
|
|
var calls int32
|
||
|
|
fn := func() (interface{}, error) {
|
||
|
|
atomic.AddInt32(&calls, 1)
|
||
|
|
return <-c, nil
|
||
|
|
}
|
||
|
|
|
||
|
|
const n = 10
|
||
|
|
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)
|
||
|
|
}
|
||
|
|
if v.(string) != "bar" {
|
||
|
|
t.Errorf("got %q; want %q", v, "bar")
|
||
|
|
}
|
||
|
|
wg.Done()
|
||
|
|
}()
|
||
|
|
}
|
||
|
|
time.Sleep(100 * time.Millisecond) // let goroutines above block
|
||
|
|
c <- "bar"
|
||
|
|
wg.Wait()
|
||
|
|
if got := atomic.LoadInt32(&calls); got != 1 {
|
||
|
|
t.Errorf("number of calls = %d; want 1", got)
|
||
|
|
}
|
||
|
|
}
|