Merge pull request #539 from foonix/gpsd-connection-management

Gpsd connection management

main/gen_gdl90.go

@@ -984,6 +984,7 @@ type settings struct {
 	ES_Enabled           bool
 	Ping_Enabled         bool
 	GPS_Enabled          bool
+	GpsdAddress          string
 	NetworkOutputs       []networkConnection
 	SerialOutputs        map[string]serialConnection
 	AHRS_Enabled         bool
@@ -1046,6 +1047,7 @@ func defaultSettings() {
 	globalSettings.UAT_Enabled = true
 	globalSettings.ES_Enabled = true
 	globalSettings.GPS_Enabled = true
+	globalSettings.GpsdAddress = "localhost:2947"
 	//FIXME: Need to change format below.
 	globalSettings.NetworkOutputs = []networkConnection{
 		{Conn: nil, Ip: "", Port: 4000, Capability: NETWORK_GDL90_STANDARD | NETWORK_AHRS_GDL90},

main/gpsd.go

@@ -6,8 +6,13 @@ import (
 	"log"
 	"math"
 	"sync"
+	"time"
 )
 
+// Channel to disconnect current gpsd connection
+var killGpsd chan struct{}
+var gps *gpsd.Session
+
 // Determine type of satellite based on PRN number.
 func satelliteType(prnId int) uint8 {
 	// TODO: Galileo
@@ -53,7 +58,9 @@ func isSbasInSolution() bool {
 
 func processDEVICES(r interface{}) {
 	devices := r.(*gpsd.DEVICESReport)
-	log.Printf("DEVICES (%d)", len(devices.Devices))
+	if globalSettings.DEBUG {
+		log.Printf("DEVICES (%d)", len(devices.Devices))
+	}
 	for _, dev := range devices.Devices {
 		log.Printf("  %s %s %x %s %s %i %s %s %i %s %s %i %d %d",
 			dev.Path,
@@ -78,7 +85,9 @@ func processDEVICES(r interface{}) {
 
 func processTPV(r interface{}) {
 	tpv := r.(*gpsd.TPVReport)
-	log.Printf("TPV", tpv.Device, tpv.Mode, tpv.Time, tpv.Tag)
+	if globalSettings.DEBUG {
+		log.Printf("TPV", tpv.Device, tpv.Mode, tpv.Time, tpv.Tag)
+	}
 
 	mySituation.mu_GPS.Lock()
 	satelliteMutex.Lock()
@@ -128,7 +137,9 @@ func processTPV(r interface{}) {
 
 func processSKY(r interface{}) {
 	sky := r.(*gpsd.SKYReport)
-	log.Printf("SKY", sky.Device, sky.Tag)
+	if globalSettings.DEBUG {
+		log.Printf("SKY", sky.Device, sky.Tag)
+	}
 
 	mySituation.mu_GPS.Lock()
 	satelliteMutex.Lock()
@@ -171,7 +182,9 @@ func processSKY(r interface{}) {
 
 func processATT(r interface{}) {
 	att := r.(*gpsd.ATTReport)
-	log.Printf("ATT", att.Device, att.Tag, att.Pitch, att.Roll, att.Heading)
+	if globalSettings.DEBUG {
+		log.Printf("ATT", att.Device, att.Tag, att.Pitch, att.Roll, att.Heading)
+	}
 
 	mySituation.mu_GPS.Lock()
 
@@ -196,18 +209,61 @@ func initGpsd() {
 	satelliteMutex = &sync.Mutex{}
 	Satellites = make(map[string]SatelliteInfo)
 
-	var gps *gpsd.Session
-	var err error
+	killGpsd = make(chan struct{})
 
-	if gps, err = gpsd.Dial(gpsd.DefaultAddress); err != nil {
-		log.Printf("Failed to connect to gpsd: %s", err)
+	if globalSettings.GPS_Enabled {
+		connectGpsd(globalSettings.GpsdAddress)
+	}
+}
+
+// Main interface for enabling and changing the gpsd connection
+// Calling will block until previous connection disconnects
+// If address is zero value, it connects to gpsd on the local machine
+func connectGpsd(address string) {
+	// kill existing monitor goroutine if it exists
+	if gps != nil {
+		disconnectGpsd()
 	}
 
-	gps.AddFilter("DEVICES", processDEVICES)
-	gps.AddFilter("TPV", processTPV)
-	gps.AddFilter("SKY", processSKY)
-	gps.AddFilter("ATT", processATT)
+	if address == "" {
+		address = gpsd.DefaultAddress
+	}
 
-	gps.SendCommand("DEVICES")
-	gps.Watch()
+	go func() {
+		for {
+			var err error
+			if gps, err = gpsd.Dial(address); err != nil {
+				log.Printf("Failed to connect to gpsd: %s", err)
+				time.Sleep(time.Second)
+				continue
+			}
+
+			log.Printf("Gpsd %s Connected.", address)
+
+			gps.AddFilter("DEVICES", processDEVICES)
+			gps.AddFilter("TPV", processTPV)
+			gps.AddFilter("SKY", processSKY)
+			gps.AddFilter("ATT", processATT)
+
+			reconnect := gps.Watch()
+
+			select {
+			case <-killGpsd:
+				log.Printf("Gpsd %s disconnecting", address)
+				gps.Close()
+				gps = nil
+				return
+			case <-reconnect:
+				log.Printf("Gpsd %s disconnected. Reconnecting..", address)
+				time.Sleep(time.Second)
+			}
+		}
+	}()
+}
+
+// Disconnect from gpsd
+// Blocks until connection is disconnected and all goroutines are stopped
+func disconnectGpsd() {
+	log.Printf("Stopping gpsd session")
+	killGpsd <- struct{}{}
 }

main/managementinterface.go

@@ -218,6 +218,12 @@ func handleSettingsSetRequest(w http.ResponseWriter, r *http.Request) {
 					case "Ping_Enabled":
 						globalSettings.Ping_Enabled = val.(bool)
 					case "GPS_Enabled":
+						switch {
+						case val.(bool) == true && globalSettings.GPS_Enabled == false:
+							connectGpsd(globalSettings.GpsdAddress)
+						case val.(bool) == false && globalSettings.GPS_Enabled == true:
+							disconnectGpsd()
+						}
 						globalSettings.GPS_Enabled = val.(bool)
 					case "AHRS_Enabled":
 						globalSettings.AHRS_Enabled = val.(bool)