lib/events: Hack to make test coverage stable from run to run

GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3484
This commit is contained in:
Jakob Borg 2016-08-08 18:09:40 +00:00
parent a4ed50ca85
commit c2d8c07137
2 changed files with 78 additions and 58 deletions

View File

@ -9,6 +9,7 @@ package events
import (
"errors"
"runtime"
stdsync "sync"
"time"
@ -47,6 +48,8 @@ const (
AllEvents = (1 << iota) - 1
)
var runningTests = false
func (t EventType) String() string {
switch t {
case Ping:
@ -186,6 +189,13 @@ func (l *Logger) Subscribe(mask EventType) *Subscription {
// We need to create the timeout timer in the stopped, non-fired state so
// that Subscription.Poll() can safely reset it and select on the timeout
// channel. This ensures the timer is stopped and the channel drained.
if runningTests {
// Make the behavior stable when running tests to avoid randomly
// varying test coverage. This ensures, in practice if not in
// theory, that the timer fires and we take the true branch of the
// next if.
runtime.Gosched()
}
if !s.timeout.Stop() {
<-s.timeout.C
}
@ -231,6 +241,14 @@ func (s *Subscription) Poll(timeout time.Duration) (Event, error) {
if !ok {
return e, ErrClosed
}
if runningTests {
// Make the behavior stable when running tests to avoid randomly
// varying test coverage. This ensures, in practice if not in
// theory, that the timer fires and we take the true branch of
// the next if.
s.timeout.Reset(0)
runtime.Gosched()
}
if !s.timeout.Stop() {
// The timeout must be stopped and possibly drained to be ready
// for reuse in the next call.

View File

@ -4,27 +4,29 @@
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at http://mozilla.org/MPL/2.0/.
package events_test
package events
import (
"fmt"
"testing"
"time"
"github.com/syncthing/syncthing/lib/events"
)
const timeout = 100 * time.Millisecond
func init() {
runningTests = true
}
func TestNewLogger(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
if l == nil {
t.Fatal("Unexpected nil Logger")
}
}
func TestSubscriber(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(0)
defer l.Unsubscribe(s)
if s == nil {
@ -33,41 +35,41 @@ func TestSubscriber(t *testing.T) {
}
func TestTimeout(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(0)
defer l.Unsubscribe(s)
_, err := s.Poll(timeout)
if err != events.ErrTimeout {
if err != ErrTimeout {
t.Fatal("Unexpected non-Timeout error:", err)
}
}
func TestEventBeforeSubscribe(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
l.Log(events.DeviceConnected, "foo")
l.Log(DeviceConnected, "foo")
s := l.Subscribe(0)
defer l.Unsubscribe(s)
_, err := s.Poll(timeout)
if err != events.ErrTimeout {
if err != ErrTimeout {
t.Fatal("Unexpected non-Timeout error:", err)
}
}
func TestEventAfterSubscribe(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.AllEvents)
s := l.Subscribe(AllEvents)
defer l.Unsubscribe(s)
l.Log(events.DeviceConnected, "foo")
l.Log(DeviceConnected, "foo")
ev, err := s.Poll(timeout)
if err != nil {
t.Fatal("Unexpected error:", err)
}
if ev.Type != events.DeviceConnected {
if ev.Type != DeviceConnected {
t.Error("Incorrect event type", ev.Type)
}
switch v := ev.Data.(type) {
@ -81,27 +83,27 @@ func TestEventAfterSubscribe(t *testing.T) {
}
func TestEventAfterSubscribeIgnoreMask(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.DeviceDisconnected)
s := l.Subscribe(DeviceDisconnected)
defer l.Unsubscribe(s)
l.Log(events.DeviceConnected, "foo")
l.Log(DeviceConnected, "foo")
_, err := s.Poll(timeout)
if err != events.ErrTimeout {
if err != ErrTimeout {
t.Fatal("Unexpected non-Timeout error:", err)
}
}
func TestBufferOverflow(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.AllEvents)
s := l.Subscribe(AllEvents)
defer l.Unsubscribe(s)
t0 := time.Now()
for i := 0; i < events.BufferSize*2; i++ {
l.Log(events.DeviceConnected, "foo")
for i := 0; i < BufferSize*2; i++ {
l.Log(DeviceConnected, "foo")
}
if time.Since(t0) > timeout {
t.Fatalf("Logging took too long")
@ -109,10 +111,10 @@ func TestBufferOverflow(t *testing.T) {
}
func TestUnsubscribe(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.AllEvents)
l.Log(events.DeviceConnected, "foo")
s := l.Subscribe(AllEvents)
l.Log(DeviceConnected, "foo")
_, err := s.Poll(timeout)
if err != nil {
@ -120,22 +122,22 @@ func TestUnsubscribe(t *testing.T) {
}
l.Unsubscribe(s)
l.Log(events.DeviceConnected, "foo")
l.Log(DeviceConnected, "foo")
_, err = s.Poll(timeout)
if err != events.ErrClosed {
if err != ErrClosed {
t.Fatal("Unexpected non-Closed error:", err)
}
}
func TestGlobalIDs(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.AllEvents)
s := l.Subscribe(AllEvents)
defer l.Unsubscribe(s)
l.Log(events.DeviceConnected, "foo")
_ = l.Subscribe(events.AllEvents)
l.Log(events.DeviceConnected, "bar")
l.Log(DeviceConnected, "foo")
_ = l.Subscribe(AllEvents)
l.Log(DeviceConnected, "bar")
ev, err := s.Poll(timeout)
if err != nil {
@ -159,15 +161,15 @@ func TestGlobalIDs(t *testing.T) {
}
func TestSubscriptionIDs(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.DeviceConnected)
s := l.Subscribe(DeviceConnected)
defer l.Unsubscribe(s)
l.Log(events.DeviceDisconnected, "a")
l.Log(events.DeviceConnected, "b")
l.Log(events.DeviceConnected, "c")
l.Log(events.DeviceDisconnected, "d")
l.Log(DeviceDisconnected, "a")
l.Log(DeviceConnected, "b")
l.Log(DeviceConnected, "c")
l.Log(DeviceDisconnected, "d")
ev, err := s.Poll(timeout)
if err != nil {
@ -193,21 +195,21 @@ func TestSubscriptionIDs(t *testing.T) {
}
ev, err = s.Poll(timeout)
if err != events.ErrTimeout {
if err != ErrTimeout {
t.Fatal("Unexpected error:", err)
}
}
func TestBufferedSub(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.AllEvents)
s := l.Subscribe(AllEvents)
defer l.Unsubscribe(s)
bs := events.NewBufferedSubscription(s, 10*events.BufferSize)
bs := NewBufferedSubscription(s, 10*BufferSize)
go func() {
for i := 0; i < 10*events.BufferSize; i++ {
l.Log(events.DeviceConnected, fmt.Sprintf("event-%d", i))
for i := 0; i < 10*BufferSize; i++ {
l.Log(DeviceConnected, fmt.Sprintf("event-%d", i))
if i%30 == 0 {
// Give the buffer routine time to pick up the events
time.Sleep(20 * time.Millisecond)
@ -216,7 +218,7 @@ func TestBufferedSub(t *testing.T) {
}()
recv := 0
for recv < 10*events.BufferSize {
for recv < 10*BufferSize {
evs := bs.Since(recv, nil)
for _, ev := range evs {
if ev.GlobalID != recv+1 {
@ -228,12 +230,12 @@ func TestBufferedSub(t *testing.T) {
}
func BenchmarkBufferedSub(b *testing.B) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.AllEvents)
s := l.Subscribe(AllEvents)
defer l.Unsubscribe(s)
bufferSize := events.BufferSize
bs := events.NewBufferedSubscription(s, bufferSize)
bufferSize := BufferSize
bs := NewBufferedSubscription(s, bufferSize)
// The coord channel paces the sender according to the receiver,
// ensuring that no events are dropped. The benchmark measures sending +
@ -249,7 +251,7 @@ func BenchmarkBufferedSub(b *testing.B) {
go func() {
defer close(done)
recv := 0
var evs []events.Event
var evs []Event
for i := 0; i < b.N; {
evs = bs.Since(recv, evs[:0])
for _, ev := range evs {
@ -270,7 +272,7 @@ func BenchmarkBufferedSub(b *testing.B) {
"and": "something else",
}
for i := 0; i < b.N; i++ {
l.Log(events.DeviceConnected, eventData)
l.Log(DeviceConnected, eventData)
<-coord
}
@ -279,16 +281,16 @@ func BenchmarkBufferedSub(b *testing.B) {
}
func TestSinceUsesSubscriptionId(t *testing.T) {
l := events.NewLogger()
l := NewLogger()
s := l.Subscribe(events.DeviceConnected)
s := l.Subscribe(DeviceConnected)
defer l.Unsubscribe(s)
bs := events.NewBufferedSubscription(s, 10*events.BufferSize)
bs := NewBufferedSubscription(s, 10*BufferSize)
l.Log(events.DeviceConnected, "a") // SubscriptionID = 1
l.Log(events.DeviceDisconnected, "b")
l.Log(events.DeviceDisconnected, "c")
l.Log(events.DeviceConnected, "d") // SubscriptionID = 2
l.Log(DeviceConnected, "a") // SubscriptionID = 1
l.Log(DeviceDisconnected, "b")
l.Log(DeviceDisconnected, "c")
l.Log(DeviceConnected, "d") // SubscriptionID = 2
// We need to loop for the events, as they may not all have been
// delivered to the buffered subscription when we get here.