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// Copyright 2018 The gVisor Authors.
//
// 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 seqatomic
import (
"sync/atomic"
"testing"
"time"
"gvisor.dev/gvisor/pkg/syncutil"
)
func TestSeqAtomicLoadUncontended(t *testing.T) {
var seq syncutil.SeqCount
const want = 1
data := want
if got := SeqAtomicLoadInt(&seq, &data); got != want {
t.Errorf("SeqAtomicLoadInt: got %v, wanted %v", got, want)
}
}
func TestSeqAtomicLoadAfterWrite(t *testing.T) {
var seq syncutil.SeqCount
var data int
const want = 1
seq.BeginWrite()
data = want
seq.EndWrite()
if got := SeqAtomicLoadInt(&seq, &data); got != want {
t.Errorf("SeqAtomicLoadInt: got %v, wanted %v", got, want)
}
}
func TestSeqAtomicLoadDuringWrite(t *testing.T) {
var seq syncutil.SeqCount
var data int
const want = 1
seq.BeginWrite()
go func() {
time.Sleep(time.Second)
data = want
seq.EndWrite()
}()
if got := SeqAtomicLoadInt(&seq, &data); got != want {
t.Errorf("SeqAtomicLoadInt: got %v, wanted %v", got, want)
}
}
func TestSeqAtomicTryLoadUncontended(t *testing.T) {
var seq syncutil.SeqCount
const want = 1
data := want
epoch := seq.BeginRead()
if got, ok := SeqAtomicTryLoadInt(&seq, epoch, &data); !ok || got != want {
t.Errorf("SeqAtomicTryLoadInt: got (%v, %v), wanted (%v, true)", got, ok, want)
}
}
func TestSeqAtomicTryLoadDuringWrite(t *testing.T) {
var seq syncutil.SeqCount
var data int
epoch := seq.BeginRead()
seq.BeginWrite()
if got, ok := SeqAtomicTryLoadInt(&seq, epoch, &data); ok {
t.Errorf("SeqAtomicTryLoadInt: got (%v, true), wanted (_, false)", got)
}
seq.EndWrite()
}
func TestSeqAtomicTryLoadAfterWrite(t *testing.T) {
var seq syncutil.SeqCount
var data int
epoch := seq.BeginRead()
seq.BeginWrite()
seq.EndWrite()
if got, ok := SeqAtomicTryLoadInt(&seq, epoch, &data); ok {
t.Errorf("SeqAtomicTryLoadInt: got (%v, true), wanted (_, false)", got)
}
}
func BenchmarkSeqAtomicLoadIntUncontended(b *testing.B) {
var seq syncutil.SeqCount
const want = 42
data := want
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
if got := SeqAtomicLoadInt(&seq, &data); got != want {
b.Fatalf("SeqAtomicLoadInt: got %v, wanted %v", got, want)
}
}
})
}
func BenchmarkSeqAtomicTryLoadIntUncontended(b *testing.B) {
var seq syncutil.SeqCount
const want = 42
data := want
b.RunParallel(func(pb *testing.PB) {
epoch := seq.BeginRead()
for pb.Next() {
if got, ok := SeqAtomicTryLoadInt(&seq, epoch, &data); !ok || got != want {
b.Fatalf("SeqAtomicTryLoadInt: got (%v, %v), wanted (%v, true)", got, ok, want)
}
}
})
}
// For comparison:
func BenchmarkAtomicValueLoadIntUncontended(b *testing.B) {
var a atomic.Value
const want = 42
a.Store(int(want))
b.RunParallel(func(pb *testing.PB) {
for pb.Next() {
if got := a.Load().(int); got != want {
b.Fatalf("atomic.Value.Load: got %v, wanted %v", got, want)
}
}
})
}
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