func (s *singularSuite) TestWithIsMasterTrue(c *gc.C) {
// When IsMaster returns true, workers get started on the underlying
// runner as usual.
s.PatchValue(&singular.PingInterval, 1*time.Millisecond)
underlyingRunner := newRunner()
conn := &fakeConn{
isMaster: true,
}
r, err := singular.New(underlyingRunner, conn)
c.Assert(err, gc.IsNil)
started := make(chan struct{}, 1)
err = r.StartWorker("worker", func() (worker.Worker, error) {
return worker.NewSimpleWorker(func(stop <-chan struct{}) error {
started <- struct{}{}
<-stop
return nil
}), nil
})
select {
case <-started:
case <-time.After(testing.LongWait):
c.Fatalf("timed out waiting for worker to start")
}
err = worker.Stop(r)
c.Assert(err, gc.IsNil)
}
func (s *singularSuite) TestPingCalledOnceOnlyForSeveralWorkers(c *gc.C) {
// Patch the ping interval to a large value, start several workers
// and check that Ping is only called once.
s.PatchValue(&singular.PingInterval, testing.LongWait)
underlyingRunner := newRunner()
conn := &fakeConn{
isMaster: false,
pinged: make(chan struct{}, 2),
}
r, err := singular.New(underlyingRunner, conn)
c.Assert(err, gc.IsNil)
for i := 0; i < 5; i++ {
name := fmt.Sprint("worker", i)
err := r.StartWorker(name, func() (worker.Worker, error) {
c.Errorf("worker unexpectedly started")
return nil, fmt.Errorf("no worker")
})
c.Assert(err, gc.IsNil)
}
time.Sleep(testing.ShortWait)
n := 0
loop:
for {
select {
case <-conn.pinged:
n++
default:
break loop
}
}
c.Assert(n, gc.Equals, 1)
}
func (a *agent) mongoWorker() (worker.Worker, error) {
dialInfo := testing.MgoDialInfo(a.hostPort)
session, err := mgo.DialWithInfo(dialInfo)
if err != nil {
return nil, err
}
mc := &mongoConn{
localHostPort: a.hostPort,
session: session,
}
runner := worker.NewRunner(
connectionIsFatal(mc),
func(err0, err1 error) bool { return true },
)
singularRunner, err := singular.New(runner, mc)
if err != nil {
return nil, fmt.Errorf("cannot start singular runner: %v", err)
}
a.notify.workerConnected()
singularRunner.StartWorker(fmt.Sprint("worker-", a.notify.id), func() (worker.Worker, error) {
return worker.NewSimpleWorker(func(stop <-chan struct{}) error {
return a.worker(session, stop)
}), nil
})
return runner, nil
}
func (*singularSuite) TestWithMasterError(c *gc.C) {
expectErr := fmt.Errorf("an error")
conn := &fakeConn{
isMasterErr: expectErr,
}
r, err := singular.New(newRunner(), conn)
c.Check(err, gc.ErrorMatches, "cannot get master status: an error")
c.Check(r, gc.IsNil)
}
func (r *singularRunnerRecord) newSingularRunner(runner worker.Runner, conn singular.Conn) (worker.Runner, error) {
sr, err := singular.New(runner, conn)
if err != nil {
return nil, err
}
return &fakeSingularRunner{
Runner: sr,
record: r,
}, nil
}
func (s *singularSuite) TestWithIsMasterFalse(c *gc.C) {
// When IsMaster returns false, dummy workers are started that
// do nothing except wait for the pinger to return an error.
s.PatchValue(&singular.PingInterval, testing.ShortWait/10)
underlyingRunner := newRunner()
conn := &fakeConn{
isMaster: false,
pinged: make(chan struct{}, 5),
}
r, err := singular.New(underlyingRunner, conn)
c.Assert(err, gc.IsNil)
err = r.StartWorker("worker", func() (worker.Worker, error) {
c.Errorf("worker unexpectedly started")
return nil, fmt.Errorf("no worker")
})
c.Assert(err, gc.IsNil)
timeout := time.NewTimer(testing.LongWait)
for i := 0; i < cap(conn.pinged); i++ {
select {
case <-conn.pinged:
case <-timeout.C:
c.Fatalf("timed out waiting for ping")
}
}
// Cause the ping to return an error; the underlying runner
// should then exit with the error it returned, because it's
// fatal.
conn.setPingErr(errFatal)
runWithTimeout(c, "wait for underlying runner", func() {
err = underlyingRunner.Wait()
})
c.Assert(err, gc.Equals, errFatal)
// Make sure there are no more pings after the ping interval by
// draining the channel and then making sure that at most
// one ping arrives within the next ShortWait.
loop1:
for {
select {
case <-conn.pinged:
default:
break loop1
}
}
timeout.Reset(testing.ShortWait)
n := 0
loop2:
for {
select {
case <-conn.pinged:
c.Assert(n, jc.LessThan, 2)
n++
case <-timeout.C:
break loop2
}
}
}