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// Copyright 2020 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 tcpip_test
import (
"sync"
"testing"
"time"
"gvisor.dev/gvisor/pkg/tcpip"
)
const (
shortDuration = 1 * time.Nanosecond
middleDuration = 100 * time.Millisecond
longDuration = 1 * time.Second
)
func TestJobReschedule(t *testing.T) {
var clock tcpip.StdClock
var wg sync.WaitGroup
var lock sync.Mutex
for i := 0; i < 2; i++ {
wg.Add(1)
go func() {
lock.Lock()
// Assigning a new timer value updates the timer's locker and function.
// This test makes sure there is no data race when reassigning a timer
// that has an active timer (even if it has been stopped as a stopped
// timer may be blocked on a lock before it can check if it has been
// stopped while another goroutine holds the same lock).
job := tcpip.NewJob(&clock, &lock, func() {
wg.Done()
})
job.Schedule(shortDuration)
lock.Unlock()
}()
}
wg.Wait()
}
func TestJobExecution(t *testing.T) {
t.Parallel()
var clock tcpip.StdClock
var lock sync.Mutex
ch := make(chan struct{})
job := tcpip.NewJob(&clock, &lock, func() {
ch <- struct{}{}
})
job.Schedule(shortDuration)
// Wait for timer to fire.
select {
case <-ch:
case <-time.After(middleDuration):
t.Fatal("timed out waiting for timer to fire")
}
// The timer should have fired only once.
select {
case <-ch:
t.Fatal("no other timers should have fired")
case <-time.After(middleDuration):
}
}
func TestCancellableTimerResetFromLongDuration(t *testing.T) {
t.Parallel()
var clock tcpip.StdClock
var lock sync.Mutex
ch := make(chan struct{})
job := tcpip.NewJob(&clock, &lock, func() { ch <- struct{}{} })
job.Schedule(middleDuration)
lock.Lock()
job.Cancel()
lock.Unlock()
job.Schedule(shortDuration)
// Wait for timer to fire.
select {
case <-ch:
case <-time.After(middleDuration):
t.Fatal("timed out waiting for timer to fire")
}
// The timer should have fired only once.
select {
case <-ch:
t.Fatal("no other timers should have fired")
case <-time.After(middleDuration):
}
}
func TestJobRescheduleFromShortDuration(t *testing.T) {
t.Parallel()
var clock tcpip.StdClock
var lock sync.Mutex
ch := make(chan struct{})
lock.Lock()
job := tcpip.NewJob(&clock, &lock, func() { ch <- struct{}{} })
job.Schedule(shortDuration)
job.Cancel()
lock.Unlock()
// Wait for timer to fire if it wasn't correctly stopped.
select {
case <-ch:
t.Fatal("timer fired after being stopped")
case <-time.After(middleDuration):
}
job.Schedule(shortDuration)
// Wait for timer to fire.
select {
case <-ch:
case <-time.After(middleDuration):
t.Fatal("timed out waiting for timer to fire")
}
// The timer should have fired only once.
select {
case <-ch:
t.Fatal("no other timers should have fired")
case <-time.After(middleDuration):
}
}
func TestJobImmediatelyCancel(t *testing.T) {
t.Parallel()
var clock tcpip.StdClock
var lock sync.Mutex
ch := make(chan struct{})
for i := 0; i < 1000; i++ {
lock.Lock()
job := tcpip.NewJob(&clock, &lock, func() { ch <- struct{}{} })
job.Schedule(shortDuration)
job.Cancel()
lock.Unlock()
}
// Wait for timer to fire if it wasn't correctly stopped.
select {
case <-ch:
t.Fatal("timer fired after being stopped")
case <-time.After(middleDuration):
}
}
func TestJobCancelledRescheduleWithoutLock(t *testing.T) {
t.Parallel()
var clock tcpip.StdClock
var lock sync.Mutex
ch := make(chan struct{})
lock.Lock()
job := tcpip.NewJob(&clock, &lock, func() { ch <- struct{}{} })
job.Schedule(shortDuration)
job.Cancel()
lock.Unlock()
for i := 0; i < 10; i++ {
job.Schedule(middleDuration)
lock.Lock()
// Sleep until the timer fires and gets blocked trying to take the lock.
time.Sleep(middleDuration * 2)
job.Cancel()
lock.Unlock()
}
// Wait for double the duration so timers that weren't correctly stopped can
// fire.
select {
case <-ch:
t.Fatal("timer fired after being stopped")
case <-time.After(middleDuration * 2):
}
}
func TestManyCancellableTimerResetAfterBlockedOnLock(t *testing.T) {
t.Parallel()
var clock tcpip.StdClock
var lock sync.Mutex
ch := make(chan struct{})
lock.Lock()
job := tcpip.NewJob(&clock, &lock, func() { ch <- struct{}{} })
job.Schedule(shortDuration)
for i := 0; i < 10; i++ {
// Sleep until the timer fires and gets blocked trying to take the lock.
time.Sleep(middleDuration)
job.Cancel()
job.Schedule(shortDuration)
}
lock.Unlock()
// Wait for double the duration for the last timer to fire.
select {
case <-ch:
case <-time.After(middleDuration):
t.Fatal("timed out waiting for timer to fire")
}
// The timer should have fired only once.
select {
case <-ch:
t.Fatal("no other timers should have fired")
case <-time.After(middleDuration):
}
}
func TestManyJobReschedulesUnderLock(t *testing.T) {
t.Parallel()
var clock tcpip.StdClock
var lock sync.Mutex
ch := make(chan struct{})
lock.Lock()
job := tcpip.NewJob(&clock, &lock, func() { ch <- struct{}{} })
job.Schedule(shortDuration)
for i := 0; i < 10; i++ {
job.Cancel()
job.Schedule(shortDuration)
}
lock.Unlock()
// Wait for double the duration for the last timer to fire.
select {
case <-ch:
case <-time.After(middleDuration):
t.Fatal("timed out waiting for timer to fire")
}
// The timer should have fired only once.
select {
case <-ch:
t.Fatal("no other timers should have fired")
case <-time.After(middleDuration):
}
}