console: implemented context timeout

cmd/geth/consolecmd.go

@@ -22,6 +22,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/cmd/utils"
 	"github.com/ethereum/go-ethereum/console"
+	"github.com/ethereum/go-ethereum/rpc"
 	"gopkg.in/urfave/cli.v1"
 )
 
@@ -67,10 +68,13 @@ func localConsole(ctx *cli.Context) error {
 	defer node.Stop()
 
 	// Attach to the newly started node and start the JavaScript console
+	client := rpc.NewClientRestartWrapper(func() rpc.Client {
 		client, err := node.Attach()
 		if err != nil {
 			utils.Fatalf("Failed to attach to the inproc geth: %v", err)
 		}
+		return client
+	})
 	config := console.Config{
 		DataDir: node.DataDir(),
 		DocRoot: ctx.GlobalString(utils.JSpathFlag.Name),
@@ -99,10 +103,14 @@ func localConsole(ctx *cli.Context) error {
 // console to it.
 func remoteConsole(ctx *cli.Context) error {
 	// Attach to a remotely running geth instance and start the JavaScript console
+	client := rpc.NewClientRestartWrapper(func() rpc.Client {
 		client, err := utils.NewRemoteRPCClient(ctx)
 		if err != nil {
 			utils.Fatalf("Unable to attach to remote geth: %v", err)
 		}
+		return client
+	})
+
 	config := console.Config{
 		DataDir: utils.MustMakeDataDir(ctx),
 		DocRoot: ctx.GlobalString(utils.JSpathFlag.Name),
@@ -137,10 +145,14 @@ func ephemeralConsole(ctx *cli.Context) error {
 	defer node.Stop()
 
 	// Attach to the newly started node and start the JavaScript console
+	client := rpc.NewClientRestartWrapper(func() rpc.Client {
 		client, err := node.Attach()
 		if err != nil {
 			utils.Fatalf("Failed to attach to the inproc geth: %v", err)
 		}
+		return client
+	})
+
 	config := console.Config{
 		DataDir: node.DataDir(),
 		DocRoot: ctx.GlobalString(utils.JSpathFlag.Name),

console/bridge.go

@@ -26,18 +26,20 @@ import (
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"github.com/ethereum/go-ethereum/rpc"
 	"github.com/robertkrimen/otto"
+	"golang.org/x/net/context"
 )
 
 // bridge is a collection of JavaScript utility methods to bride the .js runtime
 // environment and the Go RPC connection backing the remote method calls.
 type bridge struct {
-	client   rpc.Client   // RPC client to execute Ethereum requests through
+	client   *rpc.ClientRestartWrapper   // RPC client to execute Ethereum requests through
 	prompter UserPrompter // Input prompter to allow interactive user feedback
 	printer  io.Writer    // Output writer to serialize any display strings to
+	ctx context.Context
 }
 
 // newBridge creates a new JavaScript wrapper around an RPC client.
-func newBridge(client rpc.Client, prompter UserPrompter, printer io.Writer) *bridge {
+func newBridge(client *rpc.ClientRestartWrapper, prompter UserPrompter, printer io.Writer) *bridge {
 	return &bridge{
 		client:   client,
 		prompter: prompter,
@@ -45,6 +47,10 @@ func newBridge(client rpc.Client, prompter UserPrompter, printer io.Writer) *bri
 	}
 }
 
+func (b *bridge) setContext(ctx context.Context) {
+	b.ctx = ctx
+}
+
 // NewAccount is a wrapper around the personal.newAccount RPC method that uses a
 // non-echoing password prompt to aquire the passphrase and executes the original
 // RPC method (saved in jeth.newAccount) with it to actually execute the RPC call.
@@ -223,11 +229,29 @@ func (b *bridge) Send(call otto.FunctionCall) (response otto.Value) {
 
 	for i, req := range reqs {
 		// Execute the RPC request and parse the reply
-		if err = b.client.Send(&req); err != nil {
+		client := b.client.Client()
+		if err = client.Send(&req); err != nil {
 			return newErrorResponse(call, -32603, err.Error(), req.Id)
 		}
+		errc := make(chan error, 1)
+		errc2 := make(chan error)
+		go func(){
+			if b.ctx != nil {
+				select {
+				case <-b.ctx.Done():
+					b.client.Restart()
+					errc2 <- b.ctx.Err()
+				case err := <-errc:
+					errc2 <- err
+				}
+			} else {
+				errc2 <- <-errc
+			}
+		}()
 		result := make(map[string]interface{})
-		if err = b.client.Recv(&result); err != nil {
+		errc <- client.Recv(&result)
+		err := <-errc2
+		if err != nil {
 			return newErrorResponse(call, -32603, err.Error(), req.Id)
 		}
 		// Feed the reply back into the JavaScript runtime environment

console/console.go

@@ -26,6 +26,7 @@ import (
 	"regexp"
 	"sort"
 	"strings"
+	"time"
 
 	"github.com/ethereum/go-ethereum/internal/jsre"
 	"github.com/ethereum/go-ethereum/internal/web3ext"
@@ -33,6 +34,7 @@ import (
 	"github.com/mattn/go-colorable"
 	"github.com/peterh/liner"
 	"github.com/robertkrimen/otto"
+	"golang.org/x/net/context"
 )
 
 var (
@@ -52,7 +54,7 @@ const DefaultPrompt = "> "
 type Config struct {
 	DataDir  string                    // Data directory to store the console history at
 	DocRoot  string                    // Filesystem path from where to load JavaScript files from
-	Client   rpc.Client   // RPC client to execute Ethereum requests through
+	Client   *rpc.ClientRestartWrapper // RPC client to execute Ethereum requests through
 	Prompt   string                    // Input prompt prefix string (defaults to DefaultPrompt)
 	Prompter UserPrompter              // Input prompter to allow interactive user feedback (defaults to TerminalPrompter)
 	Printer  io.Writer                 // Output writer to serialize any display strings to (defaults to os.Stdout)
@@ -63,13 +65,14 @@ type Config struct {
 // JavaScript console attached to a running node via an external or in-process RPC
 // client.
 type Console struct {
-	client   rpc.Client   // RPC client to execute Ethereum requests through
+	client     *rpc.ClientRestartWrapper // RPC client to execute Ethereum requests through
 	jsre       *jsre.JSRE                // JavaScript runtime environment running the interpreter
 	prompt     string                    // Input prompt prefix string
 	prompter   UserPrompter              // Input prompter to allow interactive user feedback
 	histPath   string                    // Absolute path to the console scrollback history
 	history    []string                  // Scroll history maintained by the console
 	printer    io.Writer                 // Output writer to serialize any display strings to
+	setContext func(context.Context)
 }
 
 func New(config Config) (*Console, error) {
@@ -103,6 +106,7 @@ func New(config Config) (*Console, error) {
 func (c *Console) init(preload []string) error {
 	// Initialize the JavaScript <-> Go RPC bridge
 	bridge := newBridge(c.client, c.prompter, c.printer)
+	c.setContext = bridge.setContext
 	c.jsre.Set("jeth", struct{}{})
 
 	jethObj, _ := c.jsre.Get("jeth")
@@ -127,7 +131,7 @@ func (c *Console) init(preload []string) error {
 		return fmt.Errorf("web3 provider: %v", err)
 	}
 	// Load the supported APIs into the JavaScript runtime environment
-	apis, err := c.client.SupportedModules()
+	apis, err := c.client.Client().SupportedModules()
 	if err != nil {
 		return fmt.Errorf("api modules: %v", err)
 	}
@@ -253,7 +257,7 @@ func (c *Console) Welcome() {
 		console.log(" datadir: " + admin.datadir);
 	`)
 	// List all the supported modules for the user to call
-	if apis, err := c.client.SupportedModules(); err == nil {
+	if apis, err := c.client.Client().SupportedModules(); err == nil {
 		modules := make([]string, 0, len(apis))
 		for api, version := range apis {
 			modules = append(modules, fmt.Sprintf("%s:%s", api, version))
@@ -347,7 +351,12 @@ func (c *Console) Interactive() {
 						}
 					}
 				}
+				done := make(chan struct{})
+				ctx, _ := context.WithTimeout(context.Background(), time.Second*5)
+				c.setContext(ctx)
 				c.Evaluate(input)
+				c.setContext(nil)
+				close(done)
 				input = ""
 			}
 		}

rpc/types.go

@@ -284,3 +284,31 @@ type Client interface {
 
 	Close()
 }
+
+type ClientRestartWrapper struct {
+	client Client
+	newClientFn func() Client
+	mu sync.RWMutex
+}
+
+func NewClientRestartWrapper(newClientFn func() Client) *ClientRestartWrapper {
+	return &ClientRestartWrapper {
+		client: newClientFn(),
+		newClientFn: newClientFn,
+	}
+}
+
+func (rw *ClientRestartWrapper) Client() Client {
+	rw.mu.RLock()
+	defer rw.mu.RUnlock()
+	
+	return rw.client
+}
+
+func (rw *ClientRestartWrapper) Restart() {
+	rw.mu.Lock()
+	defer rw.mu.Unlock()
+	
+	rw.client.Close()
+	rw.client = rw.newClientFn()
+}