client/asset/{btc,dcr}: Lock connected check and timeout for shutdown

client/asset/btc: remove unused client field

client/asset/btc/btc.go

@@ -138,6 +138,7 @@ type rpcClient interface {
 	GetRawMempool() ([]*chainhash.Hash, error)
 	GetRawTransactionVerbose(txHash *chainhash.Hash) (*btcjson.TxRawResult, error)
 	RawRequest(method string, params []json.RawMessage) (json.RawMessage, error)
+	Disconnected() bool
 }
 
 // BTCCloneCFG holds clone specific parameters.
@@ -328,7 +329,6 @@ type ExchangeWallet struct {
 	// 64-bit atomic variables first. See
 	// https://golang.org/pkg/sync/atomic/#pkg-note-BUG
 	tipAtConnect      int64
-	client            *rpcclient.Client
 	node              rpcClient
 	wallet            *walletClient
 	walletInfo        *asset.WalletInfo
@@ -434,10 +434,7 @@ func BTCCloneWallet(cfg *BTCCloneCFG) (*ExchangeWallet, error) {
 		return nil, fmt.Errorf("error creating BTC RPC client: %v", err)
 	}
 
-	btc := newWallet(cfg, btcCfg, client)
-	btc.client = client
-
-	return btc, nil
+	return newWallet(cfg, btcCfg, client), nil
 }
 
 // newWallet creates the ExchangeWallet and starts the block monitor.
@@ -980,6 +977,9 @@ func (btc *ExchangeWallet) Unlock(pw string) error {
 
 // Lock locks the ExchangeWallet and the underlying bitcoind wallet.
 func (btc *ExchangeWallet) Lock() error {
+	if btc.node.Disconnected() {
+		return asset.ErrConnectionDown
+	}
 	return btc.wallet.Lock()
 }
 

client/asset/btc/btc_test.go

@@ -227,6 +227,8 @@ func (c *tRPCClient) GetRawTransactionVerbose(txHash *chainhash.Hash) (*btcjson.
 	return c.mpVerboseTxs[txHash.String()], c.rawVerboseErr
 }
 
+func (c *tRPCClient) Disconnected() bool { return false }
+
 func (c *tRPCClient) RawRequest(method string, params []json.RawMessage) (json.RawMessage, error) {
 	switch method {
 	case methodSignTx:

client/asset/dcr/dcr.go

@@ -395,9 +395,9 @@ func NewWallet(cfg *asset.WalletConfig, logger dex.Logger, network dex.Network)
 	logger.Infof("Setting up new DCR wallet at %s with TLS certificate %q.",
 		walletCfg.RPCListen, walletCfg.RPCCert)
 	dcr.client, err = newClient(walletCfg.RPCListen, walletCfg.RPCUser,
-		walletCfg.RPCPass, walletCfg.RPCCert)
+		walletCfg.RPCPass, walletCfg.RPCCert, logger)
 	if err != nil {
-		return nil, fmt.Errorf("DCR ExchangeWallet.Run error: %v", err)
+		return nil, fmt.Errorf("DCR ExchangeWallet.Run error: %w", err)
 	}
 	// Beyond this point, only node
 	dcr.node = dcr.client
@@ -436,7 +436,7 @@ func unconnectedWallet(cfg *asset.WalletConfig, dcrCfg *Config, logger dex.Logge
 
 // newClient attempts to create a new websocket connection to a dcrwallet
 // instance with the given credentials and notification handlers.
-func newClient(host, user, pass, cert string) (*rpcclient.Client, error) {
+func newClient(host, user, pass, cert string, logger dex.Logger) (*rpcclient.Client, error) {
 
 	certs, err := ioutil.ReadFile(cert)
 	if err != nil {
@@ -452,9 +452,15 @@ func newClient(host, user, pass, cert string) (*rpcclient.Client, error) {
 		DisableConnectOnNew: true,
 	}
 
-	cl, err := rpcclient.New(config, nil)
+	ntfnHandlers := &rpcclient.NotificationHandlers{
+		// Setup an on-connect handler for logging (re)connects.
+		OnClientConnected: func() {
+			logger.Infof("Connected to Decred wallet at %s", host)
+		},
+	}
+	cl, err := rpcclient.New(config, ntfnHandlers)
 	if err != nil {
-		return nil, fmt.Errorf("Failed to start dcrwallet RPC client: %v", err)
+		return nil, fmt.Errorf("Failed to start dcrwallet RPC client: %w", err)
 	}
 
 	return cl, nil
@@ -1724,6 +1730,9 @@ func (dcr *ExchangeWallet) Unlock(pw string) error {
 
 // Lock locks the exchange wallet.
 func (dcr *ExchangeWallet) Lock() error {
+	if dcr.client.Disconnected() {
+		return asset.ErrConnectionDown
+	}
 	return dcr.node.WalletLock()
 }
 

client/asset/interface.go

@@ -14,7 +14,10 @@ import (
 // has been spent or it never existed. This error may be returned from
 // AuditContract, Refund or Redeem as those methods expect the provided coin to
 // exist and be unspent.
-const CoinNotFoundError = dex.ErrorKind("coin not found")
+const (
+	CoinNotFoundError = dex.ErrorKind("coin not found")
+	ErrConnectionDown = dex.ErrorKind("wallet not connected")
+)
 
 // WalletInfo is auxiliary information about an ExchangeWallet.
 type WalletInfo struct {