Golang context.WithTimeout函数代码示例

func (mq *msgQueue) doWork(ctx context.Context) {
	// allow ten minutes for connections
	// this includes looking them up in the dht
	// dialing them, and handshaking
	conctx, cancel := context.WithTimeout(ctx, time.Minute*10)
	defer cancel()

	err := mq.network.ConnectTo(conctx, mq.p)
	if err != nil {
		log.Infof("cant connect to peer %s: %s", mq.p, err)
		// TODO: cant connect, what now?
		return
	}

	// grab outgoing message
	mq.outlk.Lock()
	wlm := mq.out
	if wlm == nil || wlm.Empty() {
		mq.outlk.Unlock()
		return
	}
	mq.out = nil
	mq.outlk.Unlock()

	sendctx, cancel := context.WithTimeout(ctx, time.Minute*5)
	defer cancel()

	// send wantlist updates
	err = mq.network.SendMessage(sendctx, mq.p, wlm)
	if err != nil {
		log.Infof("bitswap send error: %s", err)
		// TODO: what do we do if this fails?
		return
	}
}

func pingPeer(ctx context.Context, n *core.IpfsNode, pid peer.ID, numPings int) <-chan interface{} {
	outChan := make(chan interface{})
	go func() {
		defer close(outChan)

		if len(n.Peerstore.Addrs(pid)) == 0 {
			// Make sure we can find the node in question
			outChan <- &PingResult{
				Text: fmt.Sprintf("Looking up peer %s", pid.Pretty()),
			}

			ctx, cancel := context.WithTimeout(ctx, kPingTimeout)
			defer cancel()
			p, err := n.Routing.FindPeer(ctx, pid)
			if err != nil {
				outChan <- &PingResult{Text: fmt.Sprintf("Peer lookup error: %s", err)}
				return
			}
			n.Peerstore.AddAddrs(p.ID, p.Addrs, peer.TempAddrTTL)
		}

		outChan <- &PingResult{Text: fmt.Sprintf("PING %s.", pid.Pretty())}

		ctx, cancel := context.WithTimeout(ctx, kPingTimeout*time.Duration(numPings))
		defer cancel()
		pings, err := n.Ping.Ping(ctx, pid)
		if err != nil {
			log.Debugf("Ping error: %s", err)
			outChan <- &PingResult{Text: fmt.Sprintf("Ping error: %s", err)}
			return
		}

		var done bool
		var total time.Duration
		for i := 0; i < numPings && !done; i++ {
			select {
			case <-ctx.Done():
				done = true
				break
			case t, ok := <-pings:
				if !ok {
					done = true
					break
				}

				outChan <- &PingResult{
					Success: true,
					Time:    t,
				}
				total += t
				time.Sleep(time.Second)
			}
		}
		averagems := total.Seconds() * 1000 / float64(numPings)
		outChan <- &PingResult{
			Text: fmt.Sprintf("Average latency: %.2fms", averagems),
		}
	}()
	return outChan
}

func TestDeadlineFractionCancel(t *testing.T) {

	ctx1, cancel1 := context.WithTimeout(context.Background(), 10*time.Millisecond)
	ctx2, cancel2 := WithDeadlineFraction(ctx1, 0.5)

	select {
	case <-ctx1.Done():
		t.Fatal("ctx1 ended too early")
	case <-ctx2.Done():
		t.Fatal("ctx2 ended too early")
	default:
	}

	cancel2()

	select {
	case <-ctx1.Done():
		t.Fatal("ctx1 should NOT be cancelled")
	case <-ctx2.Done():
	default:
		t.Fatal("ctx2 should be cancelled")
	}

	cancel1()

	select {
	case <-ctx1.Done():
	case <-ctx2.Done():
	default:
		t.Fatal("ctx1 should be cancelled")
	}

}

// connects to providers for the given keys
func (bs *Bitswap) providerConnector(parent context.Context) {
	defer log.Info("bitswap client worker shutting down...")

	for {
		log.Event(parent, "Bitswap.ProviderConnector.Loop")
		select {
		case req := <-bs.findKeys:
			keys := req.keys
			if len(keys) == 0 {
				log.Warning("Received batch request for zero blocks")
				continue
			}
			log.Event(parent, "Bitswap.ProviderConnector.Work", logging.LoggableMap{"Keys": keys})

			// NB: Optimization. Assumes that providers of key[0] are likely to
			// be able to provide for all keys. This currently holds true in most
			// every situation. Later, this assumption may not hold as true.
			child, cancel := context.WithTimeout(req.ctx, providerRequestTimeout)
			providers := bs.network.FindProvidersAsync(child, keys[0], maxProvidersPerRequest)
			for p := range providers {
				go bs.network.ConnectTo(req.ctx, p)
			}
			cancel()

		case <-parent.Done():
			return
		}
	}
}

// GetDiagnostic runs a diagnostics request across the entire network
func (d *Diagnostics) GetDiagnostic(ctx context.Context, timeout time.Duration) ([]*DiagInfo, error) {
	log.Debug("Getting diagnostic.")
	ctx, cancel := context.WithTimeout(ctx, timeout)
	defer cancel()

	diagID := newID()
	d.diagLock.Lock()
	d.diagMap[diagID] = time.Now()
	d.diagLock.Unlock()

	log.Debug("Begin Diagnostic")

	peers := d.getPeers()
	log.Debugf("Sending diagnostic request to %d peers.", len(peers))

	pmes := newMessage(diagID)

	pmes.SetTimeoutDuration(timeout - HopTimeoutDecrement) // decrease timeout per hop
	dpeers, err := d.getDiagnosticFromPeers(ctx, d.getPeers(), pmes)
	if err != nil {
		return nil, fmt.Errorf("diagnostic from peers err: %s", err)
	}

	di := d.getDiagInfo()
	out := []*DiagInfo{di}
	for dpi := range dpeers {
		out = append(out, dpi)
	}
	return out, nil
}

func TestBasicBitswap(t *testing.T) {
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bg := blocksutil.NewBlockGenerator()

	t.Log("Test a one node trying to get one block from another")

	instances := sg.Instances(2)
	blocks := bg.Blocks(1)
	err := instances[0].Exchange.HasBlock(blocks[0])
	if err != nil {
		t.Fatal(err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
	defer cancel()
	blk, err := instances[1].Exchange.GetBlock(ctx, blocks[0].Key())
	if err != nil {
		t.Fatal(err)
	}

	t.Log(blk)
	for _, inst := range instances {
		err := inst.Exchange.Close()
		if err != nil {
			t.Fatal(err)
		}
	}
}

func TestGetBlockFromPeerAfterPeerAnnounces(t *testing.T) {

	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	block := blocks.NewBlock([]byte("block"))
	g := NewTestSessionGenerator(net)
	defer g.Close()

	peers := g.Instances(2)
	hasBlock := peers[0]
	defer hasBlock.Exchange.Close()

	if err := hasBlock.Exchange.HasBlock(block); err != nil {
		t.Fatal(err)
	}

	wantsBlock := peers[1]
	defer wantsBlock.Exchange.Close()

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	received, err := wantsBlock.Exchange.GetBlock(ctx, block.Key())
	if err != nil {
		t.Log(err)
		t.Fatal("Expected to succeed")
	}

	if !bytes.Equal(block.Data, received.Data) {
		t.Fatal("Data doesn't match")
	}
}

func TestFindPeer(t *testing.T) {
	// t.Skip("skipping test to debug another")
	if testing.Short() {
		t.SkipNow()
	}

	ctx := context.Background()

	_, peers, dhts := setupDHTS(ctx, 4, t)
	defer func() {
		for i := 0; i < 4; i++ {
			dhts[i].Close()
			dhts[i].host.Close()
		}
	}()

	connect(t, ctx, dhts[0], dhts[1])
	connect(t, ctx, dhts[1], dhts[2])
	connect(t, ctx, dhts[1], dhts[3])

	ctxT, _ := context.WithTimeout(ctx, time.Second)
	p, err := dhts[0].FindPeer(ctxT, peers[2])
	if err != nil {
		t.Fatal(err)
	}

	if p.ID == "" {
		t.Fatal("Failed to find peer.")
	}

	if p.ID != peers[2] {
		t.Fatal("Didnt find expected peer.")
	}
}

func TestGetBlocksSequential(t *testing.T) {
	var servs = Mocks(4)
	for _, s := range servs {
		defer s.Close()
	}
	bg := blocksutil.NewBlockGenerator()
	blks := bg.Blocks(50)

	var keys []key.Key
	for _, blk := range blks {
		keys = append(keys, blk.Key())
		servs[0].AddBlock(blk)
	}

	t.Log("one instance at a time, get blocks concurrently")

	for i := 1; i < len(servs); i++ {
		ctx, cancel := context.WithTimeout(context.Background(), time.Second*50)
		defer cancel()
		out := servs[i].GetBlocks(ctx, keys)
		gotten := make(map[key.Key]*blocks.Block)
		for blk := range out {
			if _, ok := gotten[blk.Key()]; ok {
				t.Fatal("Got duplicate block!")
			}
			gotten[blk.Key()] = blk
		}
		if len(gotten) != len(blks) {
			t.Fatalf("Didnt get enough blocks back: %d/%d", len(gotten), len(blks))
		}
	}
}

func (bs *Bitswap) connectToProviders(ctx context.Context, entries []wantlist.Entry) {

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	// Get providers for all entries in wantlist (could take a while)
	wg := sync.WaitGroup{}
	for _, e := range entries {
		wg.Add(1)
		go func(k key.Key) {
			defer wg.Done()

			child, cancel := context.WithTimeout(ctx, providerRequestTimeout)
			defer cancel()
			providers := bs.network.FindProvidersAsync(child, k, maxProvidersPerRequest)
			for prov := range providers {
				go func(p peer.ID) {
					bs.network.ConnectTo(ctx, p)
				}(prov)
			}
		}(e.Key)
	}

	wg.Wait() // make sure all our children do finish.
}

func TestValueGetSet(t *testing.T) {
	// t.Skip("skipping test to debug another")

	ctx := context.Background()

	dhtA := setupDHT(ctx, t)
	dhtB := setupDHT(ctx, t)

	defer dhtA.Close()
	defer dhtB.Close()
	defer dhtA.host.Close()
	defer dhtB.host.Close()

	vf := &record.ValidChecker{
		Func: func(key.Key, []byte) error {
			return nil
		},
		Sign: false,
	}
	dhtA.Validator["v"] = vf
	dhtB.Validator["v"] = vf

	connect(t, ctx, dhtA, dhtB)

	ctxT, _ := context.WithTimeout(ctx, time.Second)
	dhtA.PutValue(ctxT, "/v/hello", []byte("world"))

	ctxT, _ = context.WithTimeout(ctx, time.Second*2)
	val, err := dhtA.GetValue(ctxT, "/v/hello")
	if err != nil {
		t.Fatal(err)
	}

	if string(val) != "world" {
		t.Fatalf("Expected 'world' got '%s'", string(val))
	}

	ctxT, _ = context.WithTimeout(ctx, time.Second*2)
	val, err = dhtB.GetValue(ctxT, "/v/hello")
	if err != nil {
		t.Fatal(err)
	}

	if string(val) != "world" {
		t.Fatalf("Expected 'world' got '%s'", string(val))
	}
}

func (n *IpfsNode) HandlePeerFound(p peer.PeerInfo) {
	log.Warning("trying peer info: ", p)
	ctx, cancel := context.WithTimeout(n.Context(), discoveryConnTimeout)
	defer cancel()
	if err := n.PeerHost.Connect(ctx, p); err != nil {
		log.Warning("Failed to connect to peer found by discovery: ", err)
	}
}

func Dial(nd *core.IpfsNode, p peer.ID, protocol string) (net.Stream, error) {
	ctx, cancel := context.WithTimeout(nd.Context(), time.Second*30)
	defer cancel()
	err := nd.PeerHost.Connect(ctx, peer.PeerInfo{ID: p})
	if err != nil {
		return nil, err
	}
	return nd.PeerHost.NewStream(pro.ID(protocol), p)
}

// gatedDialAttempt is an attempt to dial a node. It is gated by the swarm's
// dial synchronization systems: dialsync and dialbackoff.
func (s *Swarm) gatedDialAttempt(ctx context.Context, p peer.ID) (*Conn, error) {
	var logdial = lgbl.Dial("swarm", s.LocalPeer(), p, nil, nil)
	defer log.EventBegin(ctx, "swarmDialAttemptSync", logdial).Done()

	// check if we already have an open connection first
	conn := s.bestConnectionToPeer(p)
	if conn != nil {
		return conn, nil
	}

	// check if there's an ongoing dial to this peer
	if ok, wait := s.dsync.Lock(p); ok {
		// ok, we have been charged to dial! let's do it.
		// if it succeeds, dial will add the conn to the swarm itself.

		defer log.EventBegin(ctx, "swarmDialAttemptStart", logdial).Done()
		ctxT, cancel := context.WithTimeout(ctx, s.dialT)
		conn, err := s.dial(ctxT, p)
		cancel()
		s.dsync.Unlock(p)
		log.Debugf("dial end %s", conn)
		if err != nil {
			log.Event(ctx, "swarmDialBackoffAdd", logdial)
			s.backf.AddBackoff(p) // let others know to backoff

			// ok, we failed. try again. (if loop is done, our error is output)
			return nil, fmt.Errorf("dial attempt failed: %s", err)
		}
		log.Event(ctx, "swarmDialBackoffClear", logdial)
		s.backf.Clear(p) // okay, no longer need to backoff
		return conn, nil

	} else {
		// we did not dial. we must wait for someone else to dial.

		// check whether we should backoff first...
		if s.backf.Backoff(p) {
			log.Event(ctx, "swarmDialBackoff", logdial)
			return nil, ErrDialBackoff
		}

		defer log.EventBegin(ctx, "swarmDialWait", logdial).Done()
		select {
		case <-wait: // wait for that other dial to finish.

			// see if it worked, OR we got an incoming dial in the meantime...
			conn := s.bestConnectionToPeer(p)
			if conn != nil {
				return conn, nil
			}
			return nil, ErrDialFailed
		case <-ctx.Done(): // or we may have to bail...
			return nil, ctx.Err()
		}
	}
}

func (d *Diagnostics) HandleMessage(ctx context.Context, s inet.Stream) error {

	cr := ctxio.NewReader(ctx, s)
	cw := ctxio.NewWriter(ctx, s)
	r := ggio.NewDelimitedReader(cr, inet.MessageSizeMax) // maxsize
	w := ggio.NewDelimitedWriter(cw)

	// deserialize msg
	pmes := new(pb.Message)
	if err := r.ReadMsg(pmes); err != nil {
		log.Debugf("Failed to decode protobuf message: %v", err)
		return nil
	}

	// Print out diagnostic
	log.Infof("[peer: %s] Got message from [%s]\n",
		d.self.Pretty(), s.Conn().RemotePeer())

	// Make sure we havent already handled this request to prevent loops
	if err := d.startDiag(pmes.GetDiagID()); err != nil {
		return nil
	}

	resp := newMessage(pmes.GetDiagID())
	resp.Data = d.getDiagInfo().Marshal()
	if err := w.WriteMsg(resp); err != nil {
		log.Debugf("Failed to write protobuf message over stream: %s", err)
		return err
	}

	timeout := pmes.GetTimeoutDuration()
	if timeout < HopTimeoutDecrement {
		return fmt.Errorf("timeout too short: %s", timeout)
	}
	ctx, cancel := context.WithTimeout(ctx, timeout)
	defer cancel()
	pmes.SetTimeoutDuration(timeout - HopTimeoutDecrement)

	dpeers, err := d.getDiagnosticFromPeers(ctx, d.getPeers(), pmes)
	if err != nil {
		log.Debugf("diagnostic from peers err: %s", err)
		return err
	}
	for b := range dpeers {
		resp := newMessage(pmes.GetDiagID())
		resp.Data = b.Marshal()
		if err := w.WriteMsg(resp); err != nil {
			log.Debugf("Failed to write protobuf message over stream: %s", err)
			return err
		}
	}

	return nil
}