Golang Stopper.ShouldQuiesce方法代碼示例

func startBankTransfers(t testing.TB, stopper *stop.Stopper, sqlDB *gosql.DB, numAccounts int) {
	const maxTransfer = 999
	for {
		select {
		case <-stopper.ShouldQuiesce():
			return // All done.
		default:
			// Keep going.
		}

		from := rand.Intn(numAccounts)
		to := rand.Intn(numAccounts - 1)
		for from == to {
			to = numAccounts - 1
		}

		amount := rand.Intn(maxTransfer)

		const update = `UPDATE bench.bank
				SET balance = CASE id WHEN $1 THEN balance-$3 WHEN $2 THEN balance+$3 END
				WHERE id IN ($1, $2)`
		util.SucceedsSoon(t, func() error {
			select {
			case <-stopper.ShouldQuiesce():
				return nil // All done.
			default:
				// Keep going.
			}
			_, err := sqlDB.Exec(update, from, to, amount)
			return err
		})
	}
}

// NewContext creates an rpc Context with the supplied values.
func NewContext(
	ambient log.AmbientContext, baseCtx *base.Config, hlcClock *hlc.Clock, stopper *stop.Stopper,
) *Context {
	ctx := &Context{
		Config: baseCtx,
	}
	if hlcClock != nil {
		ctx.localClock = hlcClock
	} else {
		ctx.localClock = hlc.NewClock(hlc.UnixNano)
	}
	ctx.breakerClock = breakerClock{
		clock: ctx.localClock,
	}
	var cancel context.CancelFunc
	ctx.masterCtx, cancel = context.WithCancel(ambient.AnnotateCtx(context.Background()))
	ctx.Stopper = stopper
	ctx.RemoteClocks = newRemoteClockMonitor(
		ctx.masterCtx, ctx.localClock, 10*defaultHeartbeatInterval)
	ctx.HeartbeatInterval = defaultHeartbeatInterval
	ctx.HeartbeatTimeout = 2 * defaultHeartbeatInterval
	ctx.conns.cache = make(map[string]*connMeta)

	stopper.RunWorker(func() {
		<-stopper.ShouldQuiesce()

		cancel()
		ctx.conns.Lock()
		for key, meta := range ctx.conns.cache {
			meta.Do(func() {
				// Make sure initialization is not in progress when we're removing the
				// conn. We need to set the error in case we win the race against the
				// real initialization code.
				if meta.err == nil {
					meta.err = &roachpb.NodeUnavailableError{}
				}
			})
			ctx.removeConnLocked(key, meta)
		}
		ctx.conns.Unlock()
	})

	return ctx
}

// ListenAndServeGRPC creates a listener and serves the specified grpc Server
// on it, closing the listener when signalled by the stopper.
func ListenAndServeGRPC(
	stopper *stop.Stopper, server *grpc.Server, addr net.Addr,
) (net.Listener, error) {
	ln, err := net.Listen(addr.Network(), addr.String())
	if err != nil {
		return ln, err
	}

	stopper.RunWorker(func() {
		<-stopper.ShouldQuiesce()
		FatalIfUnexpected(ln.Close())
		<-stopper.ShouldStop()
		server.Stop()
	})

	stopper.RunWorker(func() {
		FatalIfUnexpected(server.Serve(ln))
	})
	return ln, nil
}

// InitSenderForLocalTestCluster initializes a TxnCoordSender that can be used
// with LocalTestCluster.
func InitSenderForLocalTestCluster(
	nodeDesc *roachpb.NodeDescriptor,
	tracer opentracing.Tracer,
	clock *hlc.Clock,
	latency time.Duration,
	stores client.Sender,
	stopper *stop.Stopper,
	gossip *gossip.Gossip,
) client.Sender {
	retryOpts := base.DefaultRetryOptions()
	retryOpts.Closer = stopper.ShouldQuiesce()
	senderTransportFactory := SenderTransportFactory(tracer, stores)
	distSender := NewDistSender(DistSenderConfig{
		Clock:           clock,
		RPCRetryOptions: &retryOpts,
		nodeDescriptor:  nodeDesc,
		TransportFactory: func(
			opts SendOptions,
			rpcContext *rpc.Context,
			replicas ReplicaSlice,
			args roachpb.BatchRequest,
		) (Transport, error) {
			transport, err := senderTransportFactory(opts, rpcContext, replicas, args)
			if err != nil {
				return nil, err
			}
			return &localTestClusterTransport{transport, latency}, nil
		},
	}, gossip)

	ambient := log.AmbientContext{Tracer: tracer}
	return NewTxnCoordSender(
		ambient,
		distSender,
		clock,
		false, /* !linearizable */
		stopper,
		MakeTxnMetrics(metric.TestSampleInterval),
	)
}

// StartHeartbeat starts a periodic heartbeat to refresh this node's
// last heartbeat in the node liveness table.
func (nl *NodeLiveness) StartHeartbeat(ctx context.Context, stopper *stop.Stopper) {
	log.VEventf(ctx, 1, "starting liveness heartbeat")
	retryOpts := base.DefaultRetryOptions()
	retryOpts.Closer = stopper.ShouldQuiesce()

	stopper.RunWorker(func() {
		ambient := nl.ambientCtx
		ambient.AddLogTag("hb", nil)
		ticker := time.NewTicker(nl.heartbeatInterval)
		defer ticker.Stop()
		for {
			if !nl.pauseHeartbeat.Load().(bool) {
				ctx, sp := ambient.AnnotateCtxWithSpan(context.Background(), "heartbeat")
				ctx, cancel := context.WithTimeout(ctx, nl.heartbeatInterval)
				// Retry heartbeat in the event the conditional put fails.
				for r := retry.StartWithCtx(ctx, retryOpts); r.Next(); {
					liveness, err := nl.Self()
					if err != nil && err != ErrNoLivenessRecord {
						log.Errorf(ctx, "unexpected error getting liveness: %v", err)
					}
					if err := nl.Heartbeat(ctx, liveness); err != nil {
						if err == errSkippedHeartbeat {
							continue
						}
						log.Errorf(ctx, "failed liveness heartbeat: %v", err)
					}
					break
				}
				cancel()
				sp.Finish()
			}
			select {
			case <-ticker.C:
			case <-stopper.ShouldStop():
				return
			}
		}
	})
}