// processLoop processes the entries in the queue until the provided
// stopper signals exit.
//
// TODO(spencer): current load should factor into replica processing timer.
func (bq *baseQueue) processLoop(clock *hlc.Clock, stopper *stop.Stopper) {
stopper.RunWorker(func() {
defer func() {
bq.mu.Lock()
bq.mu.stopped = true
bq.mu.Unlock()
log.FinishEventLog(bq.ctx)
}()
// nextTime is initially nil; we don't start any timers until the queue
// becomes non-empty.
var nextTime <-chan time.Time
immediately := make(chan time.Time)
close(immediately)
for {
select {
// Exit on stopper.
case <-stopper.ShouldStop():
return
// Incoming signal sets the next time to process if there were previously
// no replicas in the queue.
case <-bq.incoming:
if nextTime == nil {
// When a replica is added, wake up immediately. This is mainly
// to facilitate testing without unnecessary sleeps.
nextTime = immediately
// In case we're in a test, still block on the impl.
bq.impl.timer()
}
// Process replicas as the timer expires.
case <-nextTime:
repl := bq.pop()
if repl != nil {
if stopper.RunTask(func() {
if err := bq.processReplica(repl, clock); err != nil {
// Maybe add failing replica to purgatory if the queue supports it.
bq.maybeAddToPurgatory(repl, err, clock, stopper)
}
}) != nil {
return
}
}
if bq.Length() == 0 {
nextTime = nil
} else {
nextTime = time.After(bq.impl.timer())
}
}
}
})
}
// New creates an instance of a gossip node.
func New(
ctx context.Context,
rpcContext *rpc.Context,
grpcServer *grpc.Server,
resolvers []resolver.Resolver,
stopper *stop.Stopper,
registry *metric.Registry,
) *Gossip {
ctx = log.WithEventLog(ctx, "gossip", "gossip")
g := &Gossip{
ctx: ctx,
Connected: make(chan struct{}),
rpcContext: rpcContext,
server: newServer(ctx, stopper, registry),
outgoing: makeNodeSet(minPeers, metric.NewGauge(MetaConnectionsOutgoingGauge)),
bootstrapping: map[string]struct{}{},
disconnected: make(chan *client, 10),
stalledCh: make(chan struct{}, 1),
stallInterval: defaultStallInterval,
bootstrapInterval: defaultBootstrapInterval,
cullInterval: defaultCullInterval,
nodeDescs: map[roachpb.NodeID]*roachpb.NodeDescriptor{},
resolverAddrs: map[util.UnresolvedAddr]resolver.Resolver{},
bootstrapAddrs: map[util.UnresolvedAddr]struct{}{},
}
stopper.AddCloser(stop.CloserFn(func() {
log.FinishEventLog(ctx)
}))
registry.AddMetric(g.outgoing.gauge)
g.clientsMu.breakers = map[string]*circuit.Breaker{}
log.Infof(g.ctx, "initial resolvers: %s", resolvers)
g.SetResolvers(resolvers)
g.mu.Lock()
// Add ourselves as a SystemConfig watcher.
g.mu.is.registerCallback(KeySystemConfig, g.updateSystemConfig)
// Add ourselves as a node descriptor watcher.
g.mu.is.registerCallback(MakePrefixPattern(KeyNodeIDPrefix), g.updateNodeAddress)
g.mu.Unlock()
RegisterGossipServer(grpcServer, g.server)
return g
}