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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 waiter
import (
"sync/atomic"
"testing"
)
type callbackStub struct {
f func(e *Entry, m EventMask)
}
// Callback implements EntryCallback.Callback.
func (c *callbackStub) Callback(e *Entry, m EventMask) {
c.f(e, m)
}
func TestEmptyQueue(t *testing.T) {
var q Queue
// Notify the zero-value of a queue.
q.Notify(EventIn)
// Register then unregister a waiter, then notify the queue.
cnt := 0
e := Entry{Callback: &callbackStub{func(*Entry, EventMask) { cnt++ }}}
q.EventRegister(&e, EventIn)
q.EventUnregister(&e)
q.Notify(EventIn)
if cnt != 0 {
t.Errorf("Callback was called when it shouldn't have been")
}
}
func TestMask(t *testing.T) {
// Register a waiter.
var q Queue
var cnt int
e := Entry{Callback: &callbackStub{func(*Entry, EventMask) { cnt++ }}}
q.EventRegister(&e, EventIn|EventErr)
// Notify with an overlapping mask.
cnt = 0
q.Notify(EventIn | EventOut)
if cnt != 1 {
t.Errorf("Callback wasn't called when it should have been")
}
// Notify with a subset mask.
cnt = 0
q.Notify(EventIn)
if cnt != 1 {
t.Errorf("Callback wasn't called when it should have been")
}
// Notify with a superset mask.
cnt = 0
q.Notify(EventIn | EventErr | EventOut)
if cnt != 1 {
t.Errorf("Callback wasn't called when it should have been")
}
// Notify with the exact same mask.
cnt = 0
q.Notify(EventIn | EventErr)
if cnt != 1 {
t.Errorf("Callback wasn't called when it should have been")
}
// Notify with a disjoint mask.
cnt = 0
q.Notify(EventOut | EventHUp)
if cnt != 0 {
t.Errorf("Callback was called when it shouldn't have been")
}
}
func TestConcurrentRegistration(t *testing.T) {
var q Queue
var cnt int
const concurrency = 1000
ch1 := make(chan struct{})
ch2 := make(chan struct{})
ch3 := make(chan struct{})
// Create goroutines that will all register/unregister concurrently.
for i := 0; i < concurrency; i++ {
go func() {
var e Entry
e.Callback = &callbackStub{func(entry *Entry, mask EventMask) {
cnt++
if entry != &e {
t.Errorf("entry = %p, want %p", entry, &e)
}
if mask != EventIn {
t.Errorf("mask = %#x want %#x", mask, EventIn)
}
}}
// Wait for notification, then register.
<-ch1
q.EventRegister(&e, EventIn|EventErr)
// Tell main goroutine that we're done registering.
ch2 <- struct{}{}
// Wait for notification, then unregister.
<-ch3
q.EventUnregister(&e)
// Tell main goroutine that we're done unregistering.
ch2 <- struct{}{}
}()
}
// Let the goroutines register.
close(ch1)
for i := 0; i < concurrency; i++ {
<-ch2
}
// Issue a notification.
q.Notify(EventIn)
if cnt != concurrency {
t.Errorf("cnt = %d, want %d", cnt, concurrency)
}
// Let the goroutine unregister.
close(ch3)
for i := 0; i < concurrency; i++ {
<-ch2
}
// Issue a notification.
q.Notify(EventIn)
if cnt != concurrency {
t.Errorf("cnt = %d, want %d", cnt, concurrency)
}
}
func TestConcurrentNotification(t *testing.T) {
var q Queue
var cnt int32
const concurrency = 1000
const waiterCount = 1000
// Register waiters.
for i := 0; i < waiterCount; i++ {
var e Entry
e.Callback = &callbackStub{func(entry *Entry, mask EventMask) {
atomic.AddInt32(&cnt, 1)
if entry != &e {
t.Errorf("entry = %p, want %p", entry, &e)
}
if mask != EventIn {
t.Errorf("mask = %#x want %#x", mask, EventIn)
}
}}
q.EventRegister(&e, EventIn|EventErr)
}
// Launch notifiers.
ch1 := make(chan struct{})
ch2 := make(chan struct{})
for i := 0; i < concurrency; i++ {
go func() {
<-ch1
q.Notify(EventIn)
ch2 <- struct{}{}
}()
}
// Let notifiers go.
close(ch1)
for i := 0; i < concurrency; i++ {
<-ch2
}
// Check the count.
if cnt != concurrency*waiterCount {
t.Errorf("cnt = %d, want %d", cnt, concurrency*waiterCount)
}
}
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