Isolates shutdown-logic to Robot/Robots/Gobot.Stop

Gobot no longer hijacks the os.Interrupt signal handler, leaving any
shutdown logic to the user.

gobot.go

@@ -2,8 +2,6 @@ package gobot
 
 import (
 	"log"
-	"os"
-	"os/signal"
 )
 
 // JSONGobot is a JSON representation of a Gobot.
@@ -33,7 +31,6 @@ func NewJSONGobot(gobot *Gobot) *JSONGobot {
 // Robots, API commands and Events.
 type Gobot struct {
 	robots *Robots
-	trap   func(chan os.Signal)
 	Commander
 	Eventer
 }
@@ -41,18 +38,15 @@ type Gobot struct {
 // NewGobot returns a new Gobot
 func NewGobot() *Gobot {
 	return &Gobot{
-		robots: &Robots{},
-		trap: func(c chan os.Signal) {
-			signal.Notify(c, os.Interrupt)
-		},
+		robots:    &Robots{},
 		Commander: NewCommander(),
 		Eventer:   NewEventer(),
 	}
 }
 
-// Start calls the Start method on each robot in it's collection of robots, and
-// stops all robots on reception of a SIGINT. Start will block the execution of
-// your main function until it receives the SIGINT.
+// Start calls the Start method on each robot in its collection of robots. On
+// error, call Stop to ensure that all robots are returned to a sane, stopped
+// state.
 func (g *Gobot) Start() (errs []error) {
 	if rerrs := g.robots.Start(); len(rerrs) > 0 {
 		for _, err := range rerrs {
@@ -61,31 +55,18 @@ func (g *Gobot) Start() (errs []error) {
 		}
 	}
 
-	c := make(chan os.Signal, 1)
-	g.trap(c)
-	if len(errs) > 0 {
-		// there was an error during start, so we immediatly pass the interrupt
-		// in order to disconnect the initialized robots, connections and devices
-		c <- os.Interrupt
+	return errs
+}
+
+// Stop calls the Stop method on each robot in its collection of robots.
+func (g *Gobot) Stop() (errs []error) {
+	if rerrs := g.robots.Stop(); len(rerrs) > 0 {
+		for _, err := range rerrs {
+			log.Println("Error:", err)
+			errs = append(errs, err)
+		}
 	}
 
-	// waiting for interrupt coming on the channel
-	_ = <-c
-	g.robots.Each(func(r *Robot) {
-		log.Println("Stopping Robot", r.Name, "...")
-		if herrs := r.Devices().Halt(); len(herrs) > 0 {
-			for _, err := range herrs {
-				log.Println("Error:", err)
-				errs = append(errs, err)
-			}
-		}
-		if cerrs := r.Connections().Finalize(); len(cerrs) > 0 {
-			for _, err := range cerrs {
-				log.Println("Error:", err)
-				errs = append(errs, err)
-			}
-		}
-	})
 	return errs
 }
 

gobot_test.go

@@ -3,7 +3,6 @@ package gobot
 import (
 	"errors"
 	"log"
-	"os"
 	"testing"
 )
 
@@ -20,9 +19,6 @@ func TestConnectionEach(t *testing.T) {
 func initTestGobot() *Gobot {
 	log.SetOutput(&NullReadWriteCloser{})
 	g := NewGobot()
-	g.trap = func(c chan os.Signal) {
-		c <- os.Interrupt
-	}
 	g.AddRobot(newTestRobot("Robot1"))
 	g.AddRobot(newTestRobot("Robot2"))
 	g.AddRobot(newTestRobot(""))
@@ -68,6 +64,7 @@ func TestGobotToJSON(t *testing.T) {
 func TestGobotStart(t *testing.T) {
 	g := initTestGobot()
 	Assert(t, len(g.Start()), 0)
+	Assert(t, len(g.Stop()), 0)
 }
 
 func TestGobotStartErrors(t *testing.T) {
@@ -90,6 +87,7 @@ func TestGobotStartErrors(t *testing.T) {
 	}
 
 	Assert(t, len(g.Start()), 1)
+	Assert(t, len(g.Stop()), 0)
 
 	testDriverStart = func() (errs []error) { return }
 	testAdaptorConnect = func() (errs []error) {
@@ -99,14 +97,11 @@ func TestGobotStartErrors(t *testing.T) {
 	}
 
 	Assert(t, len(g.Start()), 1)
+	Assert(t, len(g.Stop()), 0)
 
 	testDriverStart = func() (errs []error) { return }
 	testAdaptorConnect = func() (errs []error) { return }
 
-	g.trap = func(c chan os.Signal) {
-		c <- os.Interrupt
-	}
-
 	testDriverHalt = func() (errs []error) {
 		return []error{
 			errors.New("driver halt error 1"),
@@ -119,5 +114,6 @@ func TestGobotStartErrors(t *testing.T) {
 		}
 	}
 
-	Assert(t, len(g.Start()), 2)
+	Assert(t, len(g.Start()), 0)
+	Assert(t, len(g.Stop()), 2)
 }

robot.go

@@ -67,6 +67,19 @@ func (r *Robots) Start() (errs []error) {
 	return
 }
 
+// Stop calls the Stop method of each Robot in the collection
+func (r *Robots) Stop() (errs []error) {
+	for _, robot := range *r {
+		if errs = robot.Stop(); len(errs) > 0 {
+			for i, err := range errs {
+				errs[i] = fmt.Errorf("Robot %q: %v", robot.Name, err)
+			}
+			return
+		}
+	}
+	return
+}
+
 // Each enumerates through the Robots and calls specified callback function.
 func (r *Robots) Each(f func(*Robot)) {
 	for _, robot := range *r {
@@ -136,6 +149,24 @@ func (r *Robot) Start() (errs []error) {
 	return
 }
 
+// Stop stops a Robot's connections and Devices
+func (r *Robot) Stop() (errs []error) {
+	log.Println("Stopping Robot", r.Name, "...")
+	if heers := r.Devices().Halt(); len(heers) > 0 {
+		for _, err := range heers {
+			errs = append(errs, err)
+		}
+	}
+
+	if ceers := r.Connections().Finalize(); len(ceers) > 0 {
+		for _, err := range ceers {
+			errs = append(errs, err)
+		}
+	}
+
+	return errs
+}
+
 // Devices returns all devices associated with this Robot.
 func (r *Robot) Devices() *Devices {
 	return r.devices