func (st *State) Watch() *multiwatcher.Watcher {
st.mu.Lock()
if st.allManager == nil {
st.allManager = multiwatcher.NewStoreManager(newAllWatcherStateBacking(st))
}
st.mu.Unlock()
return multiwatcher.NewWatcher(st.allManager)
}
// StateWatcher tests the integration of the state watcher
// with the state-based backing. Most of the logic is tested elsewhere -
// this just tests end-to-end.
func (s *storeManagerStateSuite) TestStateWatcher(c *C) {
m0, err := s.State.AddMachine("series", JobManageEnviron)
c.Assert(err, IsNil)
c.Assert(m0.Id(), Equals, "0")
m1, err := s.State.AddMachine("series", JobHostUnits)
c.Assert(err, IsNil)
c.Assert(m1.Id(), Equals, "1")
b := newAllWatcherStateBacking(s.State)
aw := multiwatcher.NewStoreManager(b)
defer aw.Stop()
w := multiwatcher.NewWatcher(aw)
s.State.StartSync()
checkNext(c, w, b, []params.Delta{{
Entity: ¶ms.MachineInfo{
Id: "0",
Status: params.StatusPending,
},
}, {
Entity: ¶ms.MachineInfo{
Id: "1",
Status: params.StatusPending,
},
}}, "")
// Make some changes to the state.
err = m0.SetProvisioned("i-0", "bootstrap_nonce", nil)
c.Assert(err, IsNil)
err = m1.Destroy()
c.Assert(err, IsNil)
err = m1.EnsureDead()
c.Assert(err, IsNil)
err = m1.Remove()
c.Assert(err, IsNil)
m2, err := s.State.AddMachine("series", JobManageEnviron)
c.Assert(err, IsNil)
c.Assert(m2.Id(), Equals, "2")
s.State.StartSync()
// Check that we see the changes happen within a
// reasonable time.
var deltas []params.Delta
for {
d, err := getNext(c, w, 100*time.Millisecond)
if err == errTimeout {
break
}
c.Assert(err, IsNil)
deltas = append(deltas, d...)
}
checkDeltasEqual(c, b, deltas, []params.Delta{{
Removed: true,
Entity: ¶ms.MachineInfo{
Id: "1",
Status: params.StatusPending,
},
}, {
Entity: ¶ms.MachineInfo{
Id: "2",
Status: params.StatusPending,
},
}, {
Entity: ¶ms.MachineInfo{
Id: "0",
InstanceId: "i-0",
Status: params.StatusPending,
},
}})
err = w.Stop()
c.Assert(err, IsNil)
_, err = w.Next()
c.Assert(err, ErrorMatches, "state watcher was stopped")
}