Add sync mechanism to block when updating device lists (#1264)

* Add sync mechanism to block when updating device lists

With a timeout, mainly for sytest to fix the test
"Server correctly handles incoming m.device_list_update"
which is flakey because it assumes that when `/send` 200 OKs
that the server has updated the device lists in prep for
`/keys/query` which is not always true when using workers.

* Fix UT

* Add new working test
This commit is contained in:
Kegsay 2020-08-12 13:50:54 +01:00 committed by GitHub
parent 0835107f5b
commit d98ec12422
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3 changed files with 46 additions and 16 deletions

View File

@ -67,6 +67,11 @@ type DeviceListUpdater struct {
producer KeyChangeProducer
fedClient *gomatrixserverlib.FederationClient
workerChans []chan gomatrixserverlib.ServerName
// When device lists are stale for a user, they get inserted into this map with a channel which `Update` will
// block on or timeout via a select.
userIDToChan map[string]chan bool
userIDToChanMu *sync.Mutex
}
// DeviceListUpdaterDatabase is the subset of functionality from storage.Database required for the updater.
@ -98,12 +103,14 @@ func NewDeviceListUpdater(
numWorkers int,
) *DeviceListUpdater {
return &DeviceListUpdater{
userIDToMutex: make(map[string]*sync.Mutex),
mu: &sync.Mutex{},
db: db,
producer: producer,
fedClient: fedClient,
workerChans: make([]chan gomatrixserverlib.ServerName, numWorkers),
userIDToMutex: make(map[string]*sync.Mutex),
mu: &sync.Mutex{},
db: db,
producer: producer,
fedClient: fedClient,
workerChans: make([]chan gomatrixserverlib.ServerName, numWorkers),
userIDToChan: make(map[string]chan bool),
userIDToChanMu: &sync.Mutex{},
}
}
@ -137,6 +144,8 @@ func (u *DeviceListUpdater) mutex(userID string) *sync.Mutex {
return u.userIDToMutex[userID]
}
// Update blocks until the update has been stored in the database. It blocks primarily for satisfying sytest,
// which assumes when /send 200 OKs that the device lists have been updated.
func (u *DeviceListUpdater) Update(ctx context.Context, event gomatrixserverlib.DeviceListUpdateEvent) error {
isDeviceListStale, err := u.update(ctx, event)
if err != nil {
@ -213,7 +222,35 @@ func (u *DeviceListUpdater) notifyWorkers(userID string) {
hash := fnv.New32a()
_, _ = hash.Write([]byte(remoteServer))
index := int(hash.Sum32()) % len(u.workerChans)
ch := u.assignChannel(userID)
u.workerChans[index] <- remoteServer
select {
case <-ch:
case <-time.After(10 * time.Second):
// we don't return an error in this case as it's not a failure condition.
// we mainly block for the benefit of sytest anyway
}
}
func (u *DeviceListUpdater) assignChannel(userID string) chan bool {
u.userIDToChanMu.Lock()
defer u.userIDToChanMu.Unlock()
if ch, ok := u.userIDToChan[userID]; ok {
return ch
}
ch := make(chan bool)
u.userIDToChan[userID] = ch
return ch
}
func (u *DeviceListUpdater) clearChannel(userID string) {
u.userIDToChanMu.Lock()
defer u.userIDToChanMu.Unlock()
if ch, ok := u.userIDToChan[userID]; ok {
close(ch)
delete(u.userIDToChan, userID)
}
}
func (u *DeviceListUpdater) worker(ch chan gomatrixserverlib.ServerName) {
@ -285,6 +322,8 @@ func (u *DeviceListUpdater) processServer(serverName gomatrixserverlib.ServerNam
if err != nil {
logger.WithError(err).WithField("user_id", userID).Error("fetched device list but failed to store/emit it")
hasFailures = true
} else {
u.clearChannel(userID)
}
}
return hasFailures

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@ -204,16 +204,6 @@ func TestUpdateNoPrevID(t *testing.T) {
if err != nil {
t.Fatalf("Update returned an error: %s", err)
}
// At this point we show have this device list marked as stale and not store the keys or emitted anything
if !db.staleUsers[event.UserID] {
t.Errorf("%s not marked as stale", event.UserID)
}
if len(producer.events) > 0 {
t.Errorf("Update incorrect emitted %d device change events", len(producer.events))
}
if len(db.storedKeys) > 0 {
t.Errorf("Update incorrect stored %d device change events", len(db.storedKeys))
}
t.Log("waiting for /users/devices to be called...")
wg.Wait()
// wait a bit for db to be updated...

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@ -143,6 +143,7 @@ Device deletion propagates over federation
If remote user leaves room, changes device and rejoins we see update in sync
If remote user leaves room, changes device and rejoins we see update in /keys/changes
If remote user leaves room we no longer receive device updates
If a device list update goes missing, the server resyncs on the next one
Get left notifs in sync and /keys/changes when other user leaves
Can query remote device keys using POST after notification
Can add account data