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|
package dbus
import (
"context"
"errors"
"fmt"
"testing"
"time"
)
// Verifies that no signals are dropped, even if there is not enough space
// in the destination channel.
func TestSequentialHandlerNoDrop(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
channel := make(chan *Signal, 2)
handler.(SignalRegistrar).AddSignal(channel)
writeSignals(handler, 1000)
if err := readSignals(t, channel, 1000); err != nil {
t.Error(err)
}
}
// Verifies that signals are written to the destination channel in the
// order they are received, in a typical concurrent reader/writer scenario.
func TestSequentialHandlerSequential(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
channel := make(chan *Signal, 10)
handler.(SignalRegistrar).AddSignal(channel)
done := make(chan struct{})
// Concurrently read and write signals
go func() {
if err := readSignals(t, channel, 1000); err != nil {
t.Error(err)
}
close(done)
}()
writeSignals(handler, 1000)
<-done
}
// Test that in the case of multiple destination channels, one channel
// being blocked does not prevent the other channel receiving messages.
func TestSequentialHandlerMultipleChannel(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
channelOne := make(chan *Signal)
handler.(SignalRegistrar).AddSignal(channelOne)
channelTwo := make(chan *Signal, 10)
handler.(SignalRegistrar).AddSignal(channelTwo)
writeSignals(handler, 1000)
if err := readSignals(t, channelTwo, 1000); err != nil {
t.Error(err)
}
}
// Test that removing one channel results in no more messages being
// written to that channel.
func TestSequentialHandler_RemoveOneChannelOfOne(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
channelOne := make(chan *Signal)
handler.(SignalRegistrar).AddSignal(channelOne)
writeSignals(handler, 1000)
handler.(SignalRegistrar).RemoveSignal(channelOne)
count, closed := countSignals(channelOne)
if count > 1 {
t.Error("handler continued writing to channel after removal")
}
if closed {
t.Error("handler closed channel on .RemoveChannel()")
}
}
// Test that removing one channel results in no more messages being
// written to that channel, and the other channels are unaffected.
func TestSequentialHandler_RemoveOneChannelOfMany(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
channelOne := make(chan *Signal)
handler.(SignalRegistrar).AddSignal(channelOne)
channelTwo := make(chan *Signal, 10)
handler.(SignalRegistrar).AddSignal(channelTwo)
channelThree := make(chan *Signal, 2)
handler.(SignalRegistrar).AddSignal(channelThree)
writeSignals(handler, 1000)
handler.(SignalRegistrar).RemoveSignal(channelTwo)
defer close(channelTwo)
count, closed := countSignals(channelTwo)
if count > 10 {
t.Error("handler continued writing to channel after removal")
}
if closed {
t.Error("handler closed channel on .RemoveChannel()")
}
// Check that closing channel two does not close channel one.
if err := readSignals(t, channelOne, 1000); err != nil {
t.Error(err)
}
// Check that closing channel two does not close channel three.
if err := readSignals(t, channelThree, 1000); err != nil {
t.Error(err)
}
}
// Test that Terminate() closes all channels that were attached at the time.
func TestSequentialHandler_TerminateClosesAllChannels(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
channelOne := make(chan *Signal)
handler.(SignalRegistrar).AddSignal(channelOne)
channelTwo := make(chan *Signal, 10)
handler.(SignalRegistrar).AddSignal(channelTwo)
writeSignals(handler, 1000)
handler.(Terminator).Terminate()
count, closed := countSignals(channelOne)
if count > 1 {
t.Errorf("handler continued writing to channel after termination; read %v signals", count)
}
if !closed {
t.Error("handler failed to close channel on .Terminate()")
}
count, closed = countSignals(channelTwo)
if count > 10 {
t.Errorf("handler continued writing to channel after termination; read %v signals", count)
}
if !closed {
t.Error("handler failed to close channel on .Terminate()")
}
}
// Verifies that after termination, the handler does not process any further signals.
func TestSequentialHandler_TerminateTerminates(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
handler.(Terminator).Terminate()
channelOne := make(chan *Signal)
handler.(SignalRegistrar).AddSignal(channelOne)
writeSignals(handler, 10)
count, _ := countSignals(channelOne)
if count > 0 {
t.Errorf("handler continued operating after termination; read %v signals", count)
}
}
// Verifies calling .Terminate() more than once is equivalent to calling it just once.
func TestSequentialHandler_TerminateIdemopotent(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
handler.(Terminator).Terminate()
handler.(Terminator).Terminate()
channelOne := make(chan *Signal)
handler.(SignalRegistrar).AddSignal(channelOne)
writeSignals(handler, 10)
count, _ := countSignals(channelOne)
if count > 0 {
t.Errorf("handler continued operating after termination; read %v signals", count)
}
}
// Verifies calling RemoveSignal after Terminate() does not cause any unusual
// behaviour (panics, etc.).
func TestSequentialHandler_RemoveAfterTerminate(t *testing.T) {
t.Parallel()
handler := NewSequentialSignalHandler()
handler.(Terminator).Terminate()
handler.(Terminator).Terminate()
channelOne := make(chan *Signal)
handler.(SignalRegistrar).AddSignal(channelOne)
handler.(SignalRegistrar).RemoveSignal(channelOne)
writeSignals(handler, 10)
count, _ := countSignals(channelOne)
if count > 0 {
t.Errorf("handler continued operating after termination; read %v signals", count)
}
}
func writeSignals(handler SignalHandler, count int) {
for i := 1; i <= count; i++ {
signal := &Signal{Sequence: Sequence(i)}
handler.DeliverSignal("iface", "name", signal)
}
}
func readSignals(t *testing.T, channel <-chan *Signal, count int) error {
// Overly generous timeout
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
for i := 1; i <= count; i++ {
select {
case signal := <-channel:
if signal.Sequence != Sequence(i) {
return fmt.Errorf("Received signal out of order. Expected %v, got %v", i, signal.Sequence)
}
case <-ctx.Done():
return errors.New("Timeout occurred before all messages received")
}
}
return nil
}
func countSignals(channel <-chan *Signal) (count int, closed bool) {
count = 0
ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond*100)
defer cancel()
for {
select {
case _, ok := <-channel:
if ok {
count++
} else {
// Channel closed
return count, true
}
case <-ctx.Done():
return count, false
}
}
}
|
