// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package event
import (
"fmt"
"reflect"
"sync"
"testing"
"time"
)
func TestFeedPanics(t *testing.T) {
{
var f Feed
f.Send(int(2))
want := feedTypeError{op: "Send", got: reflect.TypeOf(uint64(0)), want: reflect.TypeOf(int(0))}
if err := checkPanic(want, func() { f.Send(uint64(2)) }); err != nil {
t.Error(err)
}
}
{
var f Feed
ch := make(chan int)
f.Subscribe(ch)
want := feedTypeError{op: "Send", got: reflect.TypeOf(uint64(0)), want: reflect.TypeOf(int(0))}
if err := checkPanic(want, func() { f.Send(uint64(2)) }); err != nil {
t.Error(err)
}
}
{
var f Feed
f.Send(int(2))
want := feedTypeError{op: "Subscribe", got: reflect.TypeOf(make(chan uint64)), want: reflect.TypeOf(make(chan<- int))}
if err := checkPanic(want, func() { f.Subscribe(make(chan uint64)) }); err != nil {
t.Error(err)
}
}
{
var f Feed
if err := checkPanic(errBadChannel, func() { f.Subscribe(make(<-chan int)) }); err != nil {
t.Error(err)
}
}
{
var f Feed
if err := checkPanic(errBadChannel, func() { f.Subscribe(int(0)) }); err != nil {
t.Error(err)
}
}
}
func checkPanic(want error, fn func()) (err error) {
defer func() {
panic := recover()
if panic == nil {
err = fmt.Errorf("didn't panic")
} else if !reflect.DeepEqual(panic, want) {
err = fmt.Errorf("panicked with wrong error: got %q, want %q", panic, want)
}
}()
fn()
return nil
}
func TestFeed(t *testing.T) {
var feed Feed
var done, subscribed sync.WaitGroup
subscriber := func(i int) {
defer done.Done()
subchan := make(chan int)
sub := feed.Subscribe(subchan)
timeout := time.NewTimer(2 * time.Second)
subscribed.Done()
select {
case v := <-subchan:
if v != 1 {
t.Errorf("%d: received value %d, want 1", i, v)
}
case <-timeout.C:
t.Errorf("%d: receive timeout", i)
}
sub.Unsubscribe()
select {
case _, ok := <-sub.Err():
if ok {
t.Errorf("%d: error channel not closed after unsubscribe", i)
}
case <-timeout.C:
t.Errorf("%d: unsubscribe timeout", i)
}
}
const n = 1000
done.Add(n)
subscribed.Add(n)
for i := 0; i < n; i++ {
go subscriber(i)
}
subscribed.Wait()
if nsent := feed.Send(1); nsent != n {
t.Errorf("first send delivered %d times, want %d", nsent, n)
}
if nsent := feed.Send(2); nsent != 0 {
t.Errorf("second send delivered %d times, want 0", nsent)
}
done.Wait()
}
func TestFeedSubscribeSameChannel(t *testing.T) {
var (
feed Feed
done sync.WaitGroup
ch = make(chan int)
sub1 = feed.Subscribe(ch)
sub2 = feed.Subscribe(ch)
_ = feed.Subscribe(ch)
)
expectSends := func(value, n int) {
if nsent := feed.Send(value); nsent != n {
t.Errorf("send delivered %d times, want %d", nsent, n)
}
done.Done()
}
expectRecv := func(wantValue, n int) {
for i := 0; i < n; i++ {
if v := <-ch; v != wantValue {
t.Errorf("received %d, want %d", v, wantValue)
}
}
}
done.Add(1)
go expectSends(1, 3)
expectRecv(1, 3)
done.Wait()
sub1.Unsubscribe()
done.Add(1)
go expectSends(2, 2)
expectRecv(2, 2)
done.Wait()
sub2.Unsubscribe()
done.Add(1)
go expectSends(3, 1)
expectRecv(3, 1)
done.Wait()
}
func TestFeedSubscribeBlockedPost(t *testing.T) {
var (
feed Feed
nsends = 2000
ch1 = make(chan int)
ch2 = make(chan int)
wg sync.WaitGroup
)
defer wg.Wait()
feed.Subscribe(ch1)
wg.Add(nsends)
for i := 0; i < nsends; i++ {
go func() {
feed.Send(99)
wg.Done()
}()
}
sub2 := feed.Subscribe(ch2)
defer sub2.Unsubscribe()
// We're done when ch1 has received N times.
// The number of receives on ch2 depends on scheduling.
for i := 0; i < nsends; {
select {
case <-ch1:
i++
case <-ch2:
}
}
}
func TestFeedUnsubscribeBlockedPost(t *testing.T) {
var (
feed Feed
nsends = 200
chans = make([]chan int, 2000)
subs = make([]Subscription, len(chans))
bchan = make(chan int)
bsub = feed.Subscribe(bchan)
wg sync.WaitGroup
)
for i := range chans {
chans[i] = make(chan int, nsends)
}
// Queue up some Sends. None of these can make progress while bchan isn't read.
wg.Add(nsends)
for i := 0; i < nsends; i++ {
go func() {
feed.Send(99)
wg.Done()
}()
}
// Subscribe the other channels.
for i, ch := range chans {
subs[i] = feed.Subscribe(ch)
}
// Unsubscribe them again.
for _, sub := range subs {
sub.Unsubscribe()
}
// Unblock the Sends.
bsub.Unsubscribe()
wg.Wait()
}
func TestFeedUnsubscribeFromInbox(t *testing.T) {
var (
feed Feed
ch1 = make(chan int)
ch2 = make(chan int)
sub1 = feed.Subscribe(ch1)
sub2 = feed.Subscribe(ch1)
sub3 = feed.Subscribe(ch2)
)
if len(feed.inbox) != 3 {
t.Errorf("inbox length != 3 after subscribe")
}
if len(feed.sendCases) != 1 {
t.Errorf("sendCases is non-empty after unsubscribe")
}
sub1.Unsubscribe()
sub2.Unsubscribe()
sub3.Unsubscribe()
if len(feed.inbox) != 0 {
t.Errorf("inbox is non-empty after unsubscribe")
}
if len(feed.sendCases) != 1 {
t.Errorf("sendCases is non-empty after unsubscribe")
}
}
func BenchmarkFeedSend1000(b *testing.B) {
var (
done sync.WaitGroup
feed Feed
nsubs = 1000
)
subscriber := func(ch <-chan int) {
for i := 0; i < b.N; i++ {
<-ch
}
done.Done()
}
done.Add(nsubs)
for i := 0; i < nsubs; i++ {
ch := make(chan int, 200)
feed.Subscribe(ch)
go subscriber(ch)
}
// The actual benchmark.
b.ResetTimer()
for i := 0; i < b.N; i++ {
if feed.Send(i) != nsubs {
panic("wrong number of sends")
}
}
b.StopTimer()
done.Wait()
}
