func (s *ManifoldSuite) TestConcurrentLockers(c *gc.C) {
worker, err := s.manifold.Start(s.getResource)
c.Assert(err, jc.ErrorIsNil)
c.Check(worker, gc.NotNil)
defer kill(worker)
var locker charmdir.Locker
err = s.manifold.Output(worker, &locker)
c.Check(err, jc.ErrorIsNil)
nlockers := 10
ch := make(chan struct{}, nlockers)
for i := 0; i < nlockers; i++ {
go func() {
locker.SetAvailable(true)
locker.SetAvailable(false)
ch <- struct{}{}
}()
}
for i := 0; i < nlockers; i++ {
select {
case <-ch:
case <-time.After(coretesting.LongWait):
c.Fatal("timed out waiting to confirm locker worker exit")
}
}
}
// updateCharmDir sets charm directory availability for sharing among
// concurrent workers according to local operation state.
func updateCharmDir(opState operation.State, locker charmdir.Locker) {
var changing bool
// Determine if the charm content is changing.
if opState.Kind == operation.Install || opState.Kind == operation.Upgrade {
changing = true
} else if opState.Kind == operation.RunHook && opState.Hook != nil && opState.Hook.Kind == hooks.UpgradeCharm {
changing = true
}
available := opState.Started && !opState.Stopped && !changing
logger.Tracef("charmdir: available=%v opState: started=%v stopped=%v changing=%v",
available, opState.Started, opState.Stopped, changing)
locker.SetAvailable(available)
}
func (s *ManifoldSuite) TestConcurrentLockersConsumers(c *gc.C) {
worker, err := s.manifold.Start(s.getResource)
c.Assert(err, jc.ErrorIsNil)
c.Check(worker, gc.NotNil)
defer kill(worker)
var consumer charmdir.Consumer
err = s.manifold.Output(worker, &consumer)
c.Check(err, jc.ErrorIsNil)
var locker charmdir.Locker
err = s.manifold.Output(worker, &locker)
c.Check(err, jc.ErrorIsNil)
nworkers := 20
before := make(chan struct{})
after := make(chan struct{}, nworkers)
for i := 0; i < nworkers; i++ {
var f func()
if i%2 == 0 {
f = func() {
<-before
err := consumer.Run(func() error {
after <- struct{}{}
return nil
})
if err == charmdir.ErrNotAvailable {
after <- struct{}{}
}
}
} else {
f = func() {
<-before
if i%3 == 0 {
locker.SetAvailable(false)
locker.SetAvailable(true)
}
after <- struct{}{}
}
}
go f()
}
locker.SetAvailable(true)
close(before)
for i := 0; i < nworkers; i++ {
select {
case <-after:
case <-time.After(coretesting.ShortWait):
c.Fatal("timed out waiting to confirm consumer worker exit")
}
}
}
func (s *ManifoldSuite) TestStartSuccess(c *gc.C) {
worker, err := s.manifold.Start(s.getResource)
c.Assert(err, jc.ErrorIsNil)
c.Check(worker, gc.NotNil)
defer kill(worker)
var consumer charmdir.Consumer
err = s.manifold.Output(worker, &consumer)
c.Check(err, jc.ErrorIsNil)
// charmdir is not available, so function will not run
err = consumer.Run(func() error { return fmt.Errorf("nope") })
c.Check(err, gc.ErrorMatches, "charmdir not available")
var locker charmdir.Locker
err = s.manifold.Output(worker, &locker)
c.Check(err, jc.ErrorIsNil)
locker.SetAvailable(true)
// charmdir is available, function will run
err = consumer.Run(func() error { return fmt.Errorf("yep") })
c.Check(err, gc.ErrorMatches, "yep")
state := "consumers have availability"
var mu sync.Mutex
beforeUnavail := make(chan struct{})
afterUnavail := make(chan struct{})
go func() {
<-beforeUnavail
locker.SetAvailable(false)
mu.Lock()
state = "no availability for you"
mu.Unlock()
close(afterUnavail)
}()
// charmdir available, Consumer.Run without error, confirm shared state.
err = consumer.Run(func() error {
mu.Lock()
c.Check(state, gc.Equals, "consumers have availability")
mu.Unlock()
return nil
})
c.Check(err, jc.ErrorIsNil)
// Locker wants to make charmdir unavailable during Consumer.Run, has to
// wait, confirm shared state.
err = consumer.Run(func() error {
close(beforeUnavail)
select {
case <-afterUnavail:
c.Fatalf("Locker failed to keep charmdir locked during a Consumer.Run")
case <-time.After(coretesting.ShortWait):
}
mu.Lock()
c.Check(state, gc.Equals, "consumers have availability")
mu.Unlock()
return nil
})
c.Check(err, jc.ErrorIsNil)
// charmdir should now be unavailable, confirm shared state.
select {
case <-afterUnavail:
mu.Lock()
c.Check(state, gc.Equals, "no availability for you")
mu.Unlock()
err = consumer.Run(func() error { return fmt.Errorf("nope") })
c.Check(err, gc.ErrorMatches, "charmdir not available")
case <-time.After(coretesting.ShortWait):
c.Fatal("timed out waiting for locker to revoke availability")
}
}