Fix: errors on 'exit' and signal handling / Feature: node panel in GUI (

#70)

* [cli][pylibs] Bugfix for OTNS 'exit' command.

* [cli][cmd][dispatcher][otns_main][otnstester][simulation][visualize] harmonized the 'exit' debug messages; bugfix that CLI Close() could lockup.

* [web] added node info panel textarea. It shows also last Tx power and Tx channel based on the info received from the 'Send' push event.

* [cli] try to avoid blocking on CLI close

* [all] better staged starting of webserver and other components. This solves the issue that webserver was being started still while rest of program was already done exiting.

* [all] remove unused code, minor updates.

cli/CmdRunner.go

@@ -34,16 +34,17 @@ import (
 	"strings"
 	"time"
 
+	"github.com/pkg/errors"
+	"github.com/simonlingoogle/go-simplelogger"
+	"gopkg.in/yaml.v3"
+
 	"github.com/openthread/ot-ns/dispatcher"
 	"github.com/openthread/ot-ns/progctx"
 	"github.com/openthread/ot-ns/radiomodel"
 	"github.com/openthread/ot-ns/simulation"
 	. "github.com/openthread/ot-ns/types"
 	"github.com/openthread/ot-ns/visualize"
 	"github.com/openthread/ot-ns/web"
-	"github.com/pkg/errors"
-	"github.com/simonlingoogle/go-simplelogger"
-	"gopkg.in/yaml.v3"
 )
 
 const (
@@ -103,45 +104,54 @@ type CmdRunner struct {
 	help          Help
 }
 
-func (rt *CmdRunner) RunCommand(cmdline string, output io.Writer) error {
-	if rt.ctx.Err() != nil {
-		return nil
-	}
-	// if character '!' is used to invoke no-node (global) context, remove it.
-	if len(cmdline) > 1 && cmdline[0] == '!' {
-		cmdline = cmdline[1:]
+func NewCmdRunner(ctx *progctx.ProgCtx, sim *simulation.Simulation) *CmdRunner {
+	cr := &CmdRunner{
+		ctx:           ctx,
+		sim:           sim,
+		contextNodeId: InvalidNodeId,
+		help:          newHelp(),
 	}
-	// run the OTNS-CLI command without node contexts
-	cmd := Command{}
+	sim.SetCmdRunner(cr)
+	return cr
+}
 
-	if err := ParseBytes([]byte(cmdline), &cmd); err != nil {
-		if _, err := fmt.Fprintf(output, "Error: %v\n", err); err != nil {
-			return err
+func (rt *CmdRunner) RunCommand(cmdline string, output io.Writer) error {
+	if rt.ctx.Err() == nil {
+		// if character '!' is used to invoke no-node (global) context, remove it.
+		if len(cmdline) > 1 && cmdline[0] == '!' {
+			cmdline = cmdline[1:]
 		}
-	} else {
-		rt.execute(&cmd, output)
-	}
+		// run the OTNS-CLI command without node context
+		cmd := Command{}
 
-	return nil
+		if err := ParseBytes([]byte(cmdline), &cmd); err != nil {
+			if _, err := fmt.Fprintf(output, "Error: %v\n", err); err != nil {
+				return err
+			}
+		} else {
+			rt.execute(&cmd, output)
+		}
+	}
+	return rt.ctx.Err()
 }
 
 func (rt *CmdRunner) HandleCommand(cmdline string, output io.Writer) error {
-	if rt.ctx.Err() != nil {
-		return nil
-	} else if rt.contextNodeId != InvalidNodeId && !isContextlessCommand(cmdline) {
-		// run the command in node context
-		cmd := Command{
-			Node: &NodeCmd{
-				Node:    NodeSelector{Id: rt.contextNodeId},
-				Command: &cmdline,
-			},
+	if rt.ctx.Err() == nil {
+		if rt.contextNodeId != InvalidNodeId && !isContextlessCommand(cmdline) {
+			// run the command in node context
+			cmd := Command{
+				Node: &NodeCmd{
+					Node:    NodeSelector{Id: rt.contextNodeId},
+					Command: &cmdline,
+				},
+			}
+			rt.execute(&cmd, output)
+		} else {
+			// run the command without node-specific context
+			return rt.RunCommand(cmdline, output)
 		}
-		rt.execute(&cmd, output)
-		return nil
-	} else {
-		// run the command without node-specific context
-		return rt.RunCommand(cmdline, output)
 	}
+	return rt.ctx.Err()
 }
 
 func (rt *CmdRunner) GetPrompt() string {
@@ -167,8 +177,6 @@ func (rt *CmdRunner) execute(cmd *Command, output io.Writer) {
 	defer func() {
 		if cc.Err() != nil {
 			cc.outputf("Error: %v\n", cc.Err())
-		} else if rt.ctx.Err() != nil {
-			cc.outputf("Error: %s\n", simulation.CommandInterruptedError)
 		} else if !cc.isBackgroundCmd {
 			cc.outputf("Done\n")
 		} else {
@@ -287,7 +295,7 @@ func (rt *CmdRunner) executeGo(cc *CommandContext, cmd *GoCmd) {
 			})
 			cc.err = <-done
 
-			if rt.ctx.Err() != nil {
+			if rt.ctx.Err() != nil || cc.err != nil {
 				break
 			}
 		}
@@ -312,12 +320,7 @@ func (rt *CmdRunner) postAsyncWait(f func(sim *simulation.Simulation)) {
 		f(rt.sim)
 		close(done)
 	})
-	select {
-	case <-done:
-		break
-	case <-rt.ctx.Done():
-		break
-	}
+	<-done
 }
 
 func (rt *CmdRunner) executeAddNode(cc *CommandContext, cmd *AddCmd) {
@@ -1030,14 +1033,3 @@ func (rt *CmdRunner) executeHelp(cc *CommandContext, cmd *HelpCmd) {
 		cc.outputStr(rt.help.outputGeneralHelp())
 	}
 }
-
-func NewCmdRunner(ctx *progctx.ProgCtx, sim *simulation.Simulation) *CmdRunner {
-	cr := &CmdRunner{
-		ctx:           ctx,
-		sim:           sim,
-		contextNodeId: InvalidNodeId,
-		help:          newHelp(),
-	}
-	sim.SetCmdRunner(cr)
-	return cr
-}

cli/runcli/runcli.go

@@ -33,6 +33,7 @@ import (
 	"strings"
 
 	"github.com/chzyer/readline"
+	"github.com/simonlingoogle/go-simplelogger"
 )
 
 type CliHandler interface {
@@ -54,8 +55,11 @@ func DefaultCliOptions() *CliOptions {
 	}
 }
 
+// TODO convert into a cli object
 var (
-	readlineInstance *readline.Instance
+	readlineInstance *readline.Instance = nil
+	waitCliClosed                       = make(chan struct{})
+	Started                             = make(chan struct{})
 )
 
 func RestorePrompt() {
@@ -64,42 +68,56 @@ func RestorePrompt() {
 	}
 }
 
-func StopCli() {
-	if readlineInstance != nil {
-		_ = readlineInstance.Close()
-	}
-}
-
-func RunCli(handler CliHandler, options *CliOptions) error {
+func getCliOptions(options *CliOptions) *CliOptions {
 	if options == nil {
 		options = DefaultCliOptions()
 	}
-
-	stdin := options.Stdin
-	if stdin == nil {
-		stdin = os.Stdin
+	if options.Stdin == nil {
+		options.Stdin = os.Stdin
 	}
-
-	stdout := options.Stdout
-	if stdout == nil {
-		stdout = os.Stdout
+	if options.Stdout == nil {
+		options.Stdout = os.Stdout
 	}
 
+	return options
+}
+
+func StopCli(options *CliOptions) {
+	// cannot call readlineInstance.Close() here, it can block
+	// (https://github.com/chzyer/readline/issues/217)
+	options = getCliOptions(options)
+	// send ETX(Ctrl-C, 0x03, readline.CharInterrupt) to avoid readline internally blocking on Runes() select.
+	_, _ = options.Stdin.WriteString("\003")
+	_ = options.Stdin.Close()
+	simplelogger.Debugf("Waiting for CLI to stop ...")
+	<-waitCliClosed
+	simplelogger.Debugf("CLI wait-for-stop done.")
+}
+
+func RunCli(handler CliHandler, options *CliOptions) error {
+	defer close(waitCliClosed)
+
+	options = getCliOptions(options)
+
+	stdin := options.Stdin
 	stdinIsTerminal := readline.IsTerminal(int(stdin.Fd()))
 	if stdinIsTerminal {
 		stdinState, err := readline.GetState(int(stdin.Fd()))
 		if err != nil {
+			close(Started)
 			return err
 		}
 		defer func() {
 			_ = readline.Restore(int(stdin.Fd()), stdinState)
 		}()
 	}
 
+	stdout := options.Stdout
 	stdoutIsTerminal := readline.IsTerminal(int(stdout.Fd()))
 	if stdoutIsTerminal {
 		stdoutState, err := readline.GetState(int(stdout.Fd()))
 		if err != nil {
+			close(Started)
 			return err
 		}
 		defer func() {
@@ -134,24 +152,28 @@ func RunCli(handler CliHandler, options *CliOptions) error {
 	l, err := readline.NewEx(readlineConfig)
 
 	if err != nil {
+		close(Started)
 		return err
 	}
 
 	defer func() {
 		_ = l.Close()
 	}()
 	readlineInstance = l
+	close(Started)
 
 	for {
 		// update the prompt and read a line
 		l.SetPrompt(handler.GetPrompt())
 		line, err := l.Readline()
 
-		if errors.Is(err, readline.ErrInterrupt) {
+		if len(line) > 0 && line[0] == readline.CharInterrupt {
+			return nil
+		} else if errors.Is(err, readline.ErrInterrupt) {
 			if len(line) == 0 {
 				return nil
 			} else {
-				continue
+				continue // Ctrl-C in midline edit only cancels the present cmd line.
 			}
 		} else if err == io.EOF {
 			return nil

cmd/otns-replay/grpc_service.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2022, The OTNS Authors.
+// Copyright (c) 2020-2023, The OTNS Authors.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
@@ -32,10 +32,11 @@ import (
 	"os"
 	"time"
 
-	pb "github.com/openthread/ot-ns/visualize/grpc/pb"
 	"github.com/pkg/errors"
 	"github.com/simonlingoogle/go-simplelogger"
 	"google.golang.org/protobuf/encoding/prototext"
+
+	pb "github.com/openthread/ot-ns/visualize/grpc/pb"
 )
 
 var (

cmd/otns/otns.go

@@ -1,4 +1,4 @@
-// Copyright (c) 2020, The OTNS Authors.
+// Copyright (c) 2020-2023, The OTNS Authors.
 // All rights reserved.
 //
 // Redistribution and use in source and binary forms, with or without
@@ -42,6 +42,6 @@ func main() {
 	otns_main.Main(ctx, func(ctx *progctx.ProgCtx, args *otns_main.MainArgs) visualize.Visualizer {
 		return nil
 	}, nil)
-	simplelogger.Debugf("OTNS exit.")
+	simplelogger.Debugf("OTNS main() exit.")
 	os.Exit(0)
 }

cmd/real/otns-silk-proxy/otns-silk-proxy.go

@@ -1,3 +1,29 @@
+// Copyright (c) 2020-2023, The OTNS Authors.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are met:
+// 1. Redistributions of source code must retain the above copyright
+//    notice, this list of conditions and the following disclaimer.
+// 2. Redistributions in binary form must reproduce the above copyright
+//    notice, this list of conditions and the following disclaimer in the
+//    documentation and/or other materials provided with the distribution.
+// 3. Neither the name of the copyright holder nor the
+//    names of its contributors may be used to endorse or promote products
+//    derived from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+// POSSIBILITY OF SUCH DAMAGE.
+
 package main
 
 import (

dispatcher/FailureCtrl_test.go

@@ -55,9 +55,6 @@ func (m mockDispatcherCallback) OnLogMessage(logEntry LogEntry) {
 func (m mockDispatcherCallback) OnNextEventTime(curTimeUs uint64, nextTimeUs uint64) {
 }
 
-func (m mockDispatcherCallback) OnStop() {
-}
-
 func TestFailureCtrlNonFailure(t *testing.T) {
 	node1 := &Node{
 		Id: 0x1,

dispatcher/Node.go

@@ -30,11 +30,11 @@ import (
 	"fmt"
 	"net"
 
+	"github.com/simonlingoogle/go-simplelogger"
+
 	"github.com/openthread/ot-ns/radiomodel"
 	"github.com/openthread/ot-ns/threadconst"
 	. "github.com/openthread/ot-ns/types"
-
-	"github.com/simonlingoogle/go-simplelogger"
 )
 
 const (