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")
}
}