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)
}
// TestStateWatcher 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 *gc.C) {
m0, err := s.State.AddMachine("quantal", JobManageEnviron)
c.Assert(err, gc.IsNil)
c.Assert(m0.Id(), gc.Equals, "0")
m1, err := s.State.AddMachine("saucy", JobHostUnits)
c.Assert(err, gc.IsNil)
c.Assert(m1.Id(), gc.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,
Life: params.Alive,
Series: "quantal",
Jobs: []params.MachineJob{JobManageEnviron.ToParams()},
Addresses: []instance.Address{},
},
}, {
Entity: ¶ms.MachineInfo{
Id: "1",
Status: params.StatusPending,
Life: params.Alive,
Series: "saucy",
Jobs: []params.MachineJob{JobHostUnits.ToParams()},
Addresses: []instance.Address{},
},
}}, "")
// Make some changes to the state.
arch := "amd64"
mem := uint64(4096)
hc := &instance.HardwareCharacteristics{
Arch: &arch,
Mem: &mem,
}
err = m0.SetProvisioned("i-0", "bootstrap_nonce", hc)
c.Assert(err, gc.IsNil)
err = m1.Destroy()
c.Assert(err, gc.IsNil)
err = m1.EnsureDead()
c.Assert(err, gc.IsNil)
err = m1.Remove()
c.Assert(err, gc.IsNil)
m2, err := s.State.AddMachine("trusty", JobHostUnits)
c.Assert(err, gc.IsNil)
c.Assert(m2.Id(), gc.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, gc.IsNil)
deltas = append(deltas, d...)
}
checkDeltasEqual(c, b, deltas, []params.Delta{{
Removed: true,
Entity: ¶ms.MachineInfo{
Id: "1",
Status: params.StatusPending,
Life: params.Alive,
Series: "saucy",
Jobs: []params.MachineJob{JobHostUnits.ToParams()},
Addresses: []instance.Address{},
},
}, {
Entity: ¶ms.MachineInfo{
Id: "2",
Status: params.StatusPending,
Life: params.Alive,
Series: "trusty",
Jobs: []params.MachineJob{JobHostUnits.ToParams()},
Addresses: []instance.Address{},
},
}, {
Entity: ¶ms.MachineInfo{
Id: "0",
InstanceId: "i-0",
Status: params.StatusPending,
Life: params.Alive,
Series: "quantal",
Jobs: []params.MachineJob{JobManageEnviron.ToParams()},
Addresses: []instance.Address{},
HardwareCharacteristics: hc,
},
}})
err = w.Stop()
c.Assert(err, gc.IsNil)
_, err = w.Next()
c.Assert(err, gc.Equals, multiwatcher.ErrWatcherStopped)
}