)
const (
- requestChannelBufSize = 100 // default size of the request channel buffer
- replyChannelBufSize = 100 // default size of the reply channel buffer
- notificationChannelBufSize = 100 // default size of the notification channel buffer
-
- defaultReplyTimeout = time.Second * 1 // default timeout for replies from VPP, can be changed with SetReplyTimeout
+ DefaultReconnectInterval = time.Second / 2 // default interval between reconnect attempts
+ DefaultMaxReconnectAttempts = 3 // default maximum number of reconnect attempts
)
var (
- healthCheckInterval = time.Second * 1 // default health check interval
- healthCheckReplyTimeout = time.Millisecond * 100 // timeout for reply to a health check
- healthCheckThreshold = 1 // number of failed health checks until the error is reported
+ RequestChanBufSize = 100 // default size of the request channel buffer
+ ReplyChanBufSize = 100 // default size of the reply channel buffer
+ NotificationChanBufSize = 100 // default size of the notification channel buffer
)
-// SetHealthCheckProbeInterval sets health check probe interval.
-// Beware: Function is not thread-safe. It is recommended to setup this parameter
-// before connecting to vpp.
-func SetHealthCheckProbeInterval(interval time.Duration) {
- healthCheckInterval = interval
-}
-
-// SetHealthCheckReplyTimeout sets timeout for reply to a health check probe.
-// If reply arrives after the timeout, check is considered as failed.
-// Beware: Function is not thread-safe. It is recommended to setup this parameter
-// before connecting to vpp.
-func SetHealthCheckReplyTimeout(timeout time.Duration) {
- healthCheckReplyTimeout = timeout
-}
-
-// SetHealthCheckThreshold sets the number of failed healthProbe checks until the error is reported.
-// Beware: Function is not thread-safe. It is recommended to setup this parameter
-// before connecting to vpp.
-func SetHealthCheckThreshold(threshold int) {
- healthCheckThreshold = threshold
-}
+var (
+ HealthCheckProbeInterval = time.Second // default health check probe interval
+ HealthCheckReplyTimeout = time.Millisecond * 100 // timeout for reply to a health check probe
+ HealthCheckThreshold = 1 // number of failed health checks until the error is reported
+ DefaultReplyTimeout = time.Second // default timeout for replies from VPP
+)
// ConnectionState represents the current state of the connection to VPP.
type ConnectionState int
// Disconnected represents state in which the connection has been dropped.
Disconnected
+
+ // Failed represents state in which the reconnecting failed after exceeding maximum number of attempts.
+ Failed
)
+func (s ConnectionState) String() string {
+ switch s {
+ case Connected:
+ return "Connected"
+ case Disconnected:
+ return "Disconnected"
+ case Failed:
+ return "Failed"
+ default:
+ return fmt.Sprintf("UnknownState(%d)", s)
+ }
+}
+
// ConnectionEvent is a notification about change in the VPP connection state.
type ConnectionEvent struct {
// Timestamp holds the time when the event has been created.
Error error
}
-var (
- connLock sync.RWMutex // lock for the global connection
- conn *Connection // global handle to the Connection (used in the message receive callback)
-)
-
// Connection represents a shared memory connection to VPP via vppAdapter.
type Connection struct {
- vpp adapter.VppAdapter // VPP adapter
- connected uint32 // non-zero if the adapter is connected to VPP
+ vppClient adapter.VppAPI // VPP binary API client
+
+ maxAttempts int // interval for reconnect attempts
+ recInterval time.Duration // maximum number of reconnect attempts
+
+ vppConnected uint32 // non-zero if the adapter is connected to VPP
codec *codec.MsgCodec // message codec
msgIDs map[string]uint16 // map of message IDs indexed by message name + CRC
maxChannelID uint32 // maximum used channel ID (the real limit is 2^15, 32-bit is used for atomic operations)
channelsLock sync.RWMutex // lock for the channels map
- channels map[uint16]*channel // map of all API channels indexed by the channel ID
+ channels map[uint16]*Channel // map of all API channels indexed by the channel ID
- notifSubscriptionsLock sync.RWMutex // lock for the subscriptions map
- notifSubscriptions map[uint16][]*api.NotifSubscription // map od all notification subscriptions indexed by message ID
+ subscriptionsLock sync.RWMutex // lock for the subscriptions map
+ subscriptions map[uint16][]*subscriptionCtx // map od all notification subscriptions indexed by message ID
pingReqID uint16 // ID if the ControlPing message
pingReplyID uint16 // ID of the ControlPingReply message
lastReplyLock sync.Mutex // lock for the last reply
lastReply time.Time // time of the last received reply from VPP
+
+ msgControlPing api.Message
+ msgControlPingReply api.Message
}
-// Connect connects to VPP using specified VPP adapter and returns the connection handle.
-// This call blocks until VPP is connected, or an error occurs. Only one connection attempt will be performed.
-func Connect(vppAdapter adapter.VppAdapter) (*Connection, error) {
- // create new connection handle
- c, err := newConnection(vppAdapter)
- if err != nil {
- return nil, err
+func newConnection(binapi adapter.VppAPI, attempts int, interval time.Duration) *Connection {
+ if attempts == 0 {
+ attempts = DefaultMaxReconnectAttempts
+ }
+ if interval == 0 {
+ interval = DefaultReconnectInterval
}
+ c := &Connection{
+ vppClient: binapi,
+ maxAttempts: attempts,
+ recInterval: interval,
+ codec: &codec.MsgCodec{},
+ msgIDs: make(map[string]uint16),
+ msgMap: make(map[uint16]api.Message),
+ channels: make(map[uint16]*Channel),
+ subscriptions: make(map[uint16][]*subscriptionCtx),
+ msgControlPing: msgControlPing,
+ msgControlPingReply: msgControlPingReply,
+ }
+ binapi.SetMsgCallback(c.msgCallback)
+ return c
+}
+
+// Connect connects to VPP API using specified adapter and returns a connection handle.
+// This call blocks until it is either connected, or an error occurs.
+// Only one connection attempt will be performed.
+func Connect(binapi adapter.VppAPI) (*Connection, error) {
+ // create new connection handle
+ c := newConnection(binapi, DefaultMaxReconnectAttempts, DefaultReconnectInterval)
+
// blocking attempt to connect to VPP
- err = c.connectVPP()
- if err != nil {
+ if err := c.connectVPP(); err != nil {
return nil, err
}
// and ConnectionState channel. This call does not block until connection is established, it
// returns immediately. The caller is supposed to watch the returned ConnectionState channel for
// Connected/Disconnected events. In case of disconnect, the library will asynchronously try to reconnect.
-func AsyncConnect(vppAdapter adapter.VppAdapter) (*Connection, chan ConnectionEvent, error) {
+func AsyncConnect(binapi adapter.VppAPI, attempts int, interval time.Duration) (*Connection, chan ConnectionEvent, error) {
// create new connection handle
- c, err := newConnection(vppAdapter)
- if err != nil {
- return nil, nil, err
- }
+ c := newConnection(binapi, attempts, interval)
// asynchronously attempt to connect to VPP
- connChan := make(chan ConnectionEvent, notificationChannelBufSize)
+ connChan := make(chan ConnectionEvent, NotificationChanBufSize)
go c.connectLoop(connChan)
return c, connChan, nil
}
-// Disconnect disconnects from VPP and releases all connection-related resources.
-func (c *Connection) Disconnect() {
- if c == nil {
- return
- }
-
- connLock.Lock()
- defer connLock.Unlock()
-
- if c.vpp != nil {
- c.disconnectVPP()
- }
- conn = nil
-}
-
-// newConnection returns new connection handle.
-func newConnection(vppAdapter adapter.VppAdapter) (*Connection, error) {
- connLock.Lock()
- defer connLock.Unlock()
-
- if conn != nil {
- return nil, errors.New("only one connection per process is supported")
- }
-
- conn = &Connection{
- vpp: vppAdapter,
- codec: &codec.MsgCodec{},
- channels: make(map[uint16]*channel),
- msgIDs: make(map[string]uint16),
- msgMap: make(map[uint16]api.Message),
- notifSubscriptions: make(map[uint16][]*api.NotifSubscription),
- }
- conn.vpp.SetMsgCallback(conn.msgCallback)
-
- return conn, nil
-}
-
// connectVPP performs blocking attempt to connect to VPP.
func (c *Connection) connectVPP() error {
log.Debug("Connecting to VPP..")
// blocking connect
- if err := c.vpp.Connect(); err != nil {
+ if err := c.vppClient.Connect(); err != nil {
return err
}
-
- log.Debugf("Connected to VPP.")
+ log.Debugf("Connected to VPP")
if err := c.retrieveMessageIDs(); err != nil {
- c.vpp.Disconnect()
+ if err := c.vppClient.Disconnect(); err != nil {
+ log.Debugf("disconnecting vpp client failed: %v", err)
+ }
return fmt.Errorf("VPP is incompatible: %v", err)
}
// store connected state
- atomic.StoreUint32(&c.connected, 1)
+ atomic.StoreUint32(&c.vppConnected, 1)
return nil
}
-func getMsgNameWithCrc(x api.Message) string {
- return x.GetMessageName() + "_" + x.GetCrcString()
-}
-
-// retrieveMessageIDs retrieves IDs for all registered messages and stores them in map
-func (c *Connection) retrieveMessageIDs() (err error) {
- t := time.Now()
-
- var addMsg = func(msgID uint16, msg api.Message) {
- c.msgIDs[getMsgNameWithCrc(msg)] = msgID
- c.msgMap[msgID] = msg
+// Disconnect disconnects from VPP API and releases all connection-related resources.
+func (c *Connection) Disconnect() {
+ if c == nil {
+ return
}
-
- msgs := api.GetAllMessages()
-
- for name, msg := range msgs {
- msgID, err := c.vpp.GetMsgID(msg.GetMessageName(), msg.GetCrcString())
- if err != nil {
- return err
- }
-
- addMsg(msgID, msg)
-
- if msg.GetMessageName() == msgControlPing.GetMessageName() {
- c.pingReqID = msgID
- msgControlPing = reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
- } else if msg.GetMessageName() == msgControlPingReply.GetMessageName() {
- c.pingReplyID = msgID
- msgControlPingReply = reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
- }
-
- if debugMsgIDs {
- log.Debugf("message %q (%s) has ID: %d", name, getMsgNameWithCrc(msg), msgID)
- }
+ if c.vppClient != nil {
+ c.disconnectVPP()
}
+}
- log.Debugf("retrieving %d message IDs took %s", len(msgs), time.Since(t))
+// disconnectVPP disconnects from VPP in case it is connected.
+func (c *Connection) disconnectVPP() {
+ if atomic.CompareAndSwapUint32(&c.vppConnected, 1, 0) {
+ log.Debug("Disconnecting from VPP..")
- // fallback for control ping when vpe package is not imported
- if c.pingReqID == 0 {
- c.pingReqID, err = c.vpp.GetMsgID(msgControlPing.GetMessageName(), msgControlPing.GetCrcString())
- if err != nil {
- return err
- }
- addMsg(c.pingReqID, msgControlPing)
- }
- if c.pingReplyID == 0 {
- c.pingReplyID, err = c.vpp.GetMsgID(msgControlPingReply.GetMessageName(), msgControlPingReply.GetCrcString())
- if err != nil {
- return err
+ if err := c.vppClient.Disconnect(); err != nil {
+ log.Debugf("Disconnect from VPP failed: %v", err)
}
- addMsg(c.pingReplyID, msgControlPingReply)
+ log.Debug("Disconnected from VPP")
}
-
- return nil
}
-// GetMessageID returns message identifier of given API message.
-func (c *Connection) GetMessageID(msg api.Message) (uint16, error) {
- if c == nil {
- return 0, errors.New("nil connection passed in")
- }
-
- if msgID, ok := c.msgIDs[getMsgNameWithCrc(msg)]; ok {
- return msgID, nil
- }
+func (c *Connection) NewAPIChannel() (api.Channel, error) {
+ return c.newAPIChannel(RequestChanBufSize, ReplyChanBufSize)
+}
- return 0, fmt.Errorf("unknown message: %s (%s)", msg.GetMessageName(), msg.GetCrcString())
+func (c *Connection) NewAPIChannelBuffered(reqChanBufSize, replyChanBufSize int) (api.Channel, error) {
+ return c.newAPIChannel(reqChanBufSize, replyChanBufSize)
}
-// LookupByID looks up message name and crc by ID.
-func (c *Connection) LookupByID(msgID uint16) (api.Message, error) {
+// NewAPIChannelBuffered returns a new API channel for communication with VPP via govpp core.
+// It allows to specify custom buffer sizes for the request and reply Go channels.
+func (c *Connection) newAPIChannel(reqChanBufSize, replyChanBufSize int) (*Channel, error) {
if c == nil {
return nil, errors.New("nil connection passed in")
}
- if msg, ok := c.msgMap[msgID]; ok {
- return msg, nil
- }
+ // create new channel
+ chID := uint16(atomic.AddUint32(&c.maxChannelID, 1) & 0x7fff)
+ channel := newChannel(chID, c, c.codec, c, reqChanBufSize, replyChanBufSize)
- return nil, fmt.Errorf("unknown message ID: %d", msgID)
+ // store API channel within the client
+ c.channelsLock.Lock()
+ c.channels[chID] = channel
+ c.channelsLock.Unlock()
+
+ // start watching on the request channel
+ go c.watchRequests(channel)
+
+ return channel, nil
}
-// disconnectVPP disconnects from VPP in case it is connected.
-func (c *Connection) disconnectVPP() {
- if atomic.CompareAndSwapUint32(&c.connected, 1, 0) {
- c.vpp.Disconnect()
- }
+// releaseAPIChannel releases API channel that needs to be closed.
+func (c *Connection) releaseAPIChannel(ch *Channel) {
+ log.WithFields(logger.Fields{
+ "channel": ch.id,
+ }).Debug("API channel released")
+
+ // delete the channel from channels map
+ c.channelsLock.Lock()
+ delete(c.channels, ch.id)
+ c.channelsLock.Unlock()
}
// connectLoop attempts to connect to VPP until it succeeds.
// Then it continues with healthCheckLoop.
func (c *Connection) connectLoop(connChan chan ConnectionEvent) {
+ var reconnectAttempts int
+
// loop until connected
for {
- if err := c.vpp.WaitReady(); err != nil {
- log.Warnf("wait ready failed: %v", err)
+ if err := c.vppClient.WaitReady(); err != nil {
+ log.Debugf("wait ready failed: %v", err)
}
if err := c.connectVPP(); err == nil {
// signal connected event
connChan <- ConnectionEvent{Timestamp: time.Now(), State: Connected}
break
+ } else if reconnectAttempts < c.maxAttempts {
+ reconnectAttempts++
+ log.Warnf("connecting failed (attempt %d/%d): %v", reconnectAttempts, c.maxAttempts, err)
+ time.Sleep(c.recInterval)
} else {
- log.Errorf("connecting to VPP failed: %v", err)
- time.Sleep(time.Second)
+ connChan <- ConnectionEvent{Timestamp: time.Now(), State: Failed, Error: err}
+ return
}
}
// send health check probes until an error or timeout occurs
for {
// sleep until next health check probe period
- time.Sleep(healthCheckInterval)
+ time.Sleep(HealthCheckProbeInterval)
- if atomic.LoadUint32(&c.connected) == 0 {
+ if atomic.LoadUint32(&c.vppConnected) == 0 {
// Disconnect has been called in the meantime, return the healthcheck - reconnect loop
log.Debug("Disconnected on request, exiting health check loop.")
return
}
// send the control ping request
- ch.reqChan <- &vppRequest{msg: msgControlPing}
+ ch.reqChan <- &vppRequest{msg: c.msgControlPing}
for {
// expect response within timeout period
case vppReply := <-ch.replyChan:
err = vppReply.err
- case <-time.After(healthCheckReplyTimeout):
+ case <-time.After(HealthCheckReplyTimeout):
err = ErrProbeTimeout
// check if time since last reply from any other
sinceLastReply = time.Since(c.lastReply)
c.lastReplyLock.Unlock()
- if sinceLastReply < healthCheckReplyTimeout {
+ if sinceLastReply < HealthCheckReplyTimeout {
log.Warnf("VPP health check probe timing out, but some request on other channel was received %v ago, continue waiting!", sinceLastReply)
continue
}
if err == ErrProbeTimeout {
failedChecks++
- log.Warnf("VPP health check probe timed out after %v (%d. timeout)", healthCheckReplyTimeout, failedChecks)
- if failedChecks > healthCheckThreshold {
+ log.Warnf("VPP health check probe timed out after %v (%d. timeout)", HealthCheckReplyTimeout, failedChecks)
+ if failedChecks > HealthCheckThreshold {
// in case of exceeded failed check treshold, assume VPP disconnected
- log.Errorf("VPP health check exceeded treshold for timeouts (>%d), assuming disconnect", healthCheckThreshold)
+ log.Errorf("VPP health check exceeded treshold for timeouts (>%d), assuming disconnect", HealthCheckThreshold)
connChan <- ConnectionEvent{Timestamp: time.Now(), State: Disconnected}
break
}
c.connectLoop(connChan)
}
-func (c *Connection) NewAPIChannel() (api.Channel, error) {
- return c.newAPIChannel(requestChannelBufSize, replyChannelBufSize)
+func getMsgNameWithCrc(x api.Message) string {
+ return x.GetMessageName() + "_" + x.GetCrcString()
}
-func (c *Connection) NewAPIChannelBuffered(reqChanBufSize, replyChanBufSize int) (api.Channel, error) {
- return c.newAPIChannel(reqChanBufSize, replyChanBufSize)
+func getMsgFactory(msg api.Message) func() api.Message {
+ return func() api.Message {
+ return reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
+ }
}
-// NewAPIChannelBuffered returns a new API channel for communication with VPP via govpp core.
-// It allows to specify custom buffer sizes for the request and reply Go channels.
-func (c *Connection) newAPIChannel(reqChanBufSize, replyChanBufSize int) (*channel, error) {
+// GetMessageID returns message identifier of given API message.
+func (c *Connection) GetMessageID(msg api.Message) (uint16, error) {
if c == nil {
- return nil, errors.New("nil connection passed in")
+ return 0, errors.New("nil connection passed in")
}
- chID := uint16(atomic.AddUint32(&c.maxChannelID, 1) & 0x7fff)
- ch := &channel{
- id: chID,
- replyTimeout: defaultReplyTimeout,
- msgDecoder: c.codec,
- msgIdentifier: c,
- reqChan: make(chan *vppRequest, reqChanBufSize),
- replyChan: make(chan *vppReply, replyChanBufSize),
- notifSubsChan: make(chan *subscriptionRequest, reqChanBufSize),
- notifSubsReplyChan: make(chan error, replyChanBufSize),
+ if msgID, ok := c.msgIDs[getMsgNameWithCrc(msg)]; ok {
+ return msgID, nil
}
- // store API channel within the client
- c.channelsLock.Lock()
- c.channels[chID] = ch
- c.channelsLock.Unlock()
+ msgID, err := c.vppClient.GetMsgID(msg.GetMessageName(), msg.GetCrcString())
+ if err != nil {
+ return 0, err
+ }
- // start watching on the request channel
- go c.watchRequests(ch)
+ c.msgIDs[getMsgNameWithCrc(msg)] = msgID
+ c.msgMap[msgID] = msg
- return ch, nil
+ return msgID, nil
}
-// releaseAPIChannel releases API channel that needs to be closed.
-func (c *Connection) releaseAPIChannel(ch *channel) {
- log.WithFields(logger.Fields{
- "channel": ch.id,
- }).Debug("API channel released")
+// LookupByID looks up message name and crc by ID.
+func (c *Connection) LookupByID(msgID uint16) (api.Message, error) {
+ if c == nil {
+ return nil, errors.New("nil connection passed in")
+ }
- // delete the channel from channels map
- c.channelsLock.Lock()
- delete(c.channels, ch.id)
- c.channelsLock.Unlock()
+ if msg, ok := c.msgMap[msgID]; ok {
+ return msg, nil
+ }
+
+ return nil, fmt.Errorf("unknown message ID: %d", msgID)
+}
+
+// retrieveMessageIDs retrieves IDs for all registered messages and stores them in map
+func (c *Connection) retrieveMessageIDs() (err error) {
+ t := time.Now()
+
+ msgs := api.GetRegisteredMessages()
+
+ var n int
+ for name, msg := range msgs {
+ msgID, err := c.GetMessageID(msg)
+ if err != nil {
+ log.Debugf("retrieving msgID for %s failed: %v", name, err)
+ continue
+ }
+ n++
+
+ if c.pingReqID == 0 && msg.GetMessageName() == c.msgControlPing.GetMessageName() {
+ c.pingReqID = msgID
+ c.msgControlPing = reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
+ } else if c.pingReplyID == 0 && msg.GetMessageName() == c.msgControlPingReply.GetMessageName() {
+ c.pingReplyID = msgID
+ c.msgControlPingReply = reflect.New(reflect.TypeOf(msg).Elem()).Interface().(api.Message)
+ }
+
+ if debugMsgIDs {
+ log.Debugf("message %q (%s) has ID: %d", name, getMsgNameWithCrc(msg), msgID)
+ }
+ }
+ log.Debugf("retrieved %d/%d msgIDs (took %s)", n, len(msgs), time.Since(t))
+
+ return nil
}