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enervent-ctrl
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#9 Mutex locking for bus operations

This commit is contained in:
Jarno Rankinen 2023-01-29 22:09:37 +02:00
parent 8143414c39
commit 876123e518
1 changed files with 9 additions and 1 deletions
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8
enervent-ctrl-go/pingvinKL/pingvinKL.go
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@ -5,6 +5,7 @@ import (
"log" "log"
"os" "os"
"strings" "strings"
"sync"
"time" "time"
"github.com/goburrow/modbus" "github.com/goburrow/modbus"
@ -27,6 +28,7 @@ func newCoil(symbol string, description string) pingvinCoil {
// unit modbus data // unit modbus data
type PingvinKL struct { type PingvinKL struct {
Coils []pingvinCoil Coils []pingvinCoil
buslock *sync.Mutex
} }
// read a CSV file containing data for coils or registers // read a CSV file containing data for coils or registers
@ -64,6 +66,7 @@ func (p PingvinKL) getHandler() *modbus.RTUClientHandler {
func (p PingvinKL) Update() { func (p PingvinKL) Update() {
handler := p.getHandler() handler := p.getHandler()
p.buslock.Lock()
err := handler.Connect() err := handler.Connect()
if err != nil { if err != nil {
log.Fatal("Update: handler.Connect: ", err) log.Fatal("Update: handler.Connect: ", err)
@ -74,6 +77,7 @@ func (p PingvinKL) Update() {
if err != nil { if err != nil {
log.Fatal("Update: client.ReadCoils:", err) log.Fatal("Update: client.ReadCoils:", err)
} }
p.buslock.Unlock()
// modbus.ReadCoils returns a byte array, with the first byte's bits representing coil values 0-7, // modbus.ReadCoils returns a byte array, with the first byte's bits representing coil values 0-7,
// second byte coils 8-15 etc. // second byte coils 8-15 etc.
// Within each byte, LSB represents the lowest n coil while MSB is the highest // Within each byte, LSB represents the lowest n coil while MSB is the highest
@ -95,6 +99,7 @@ func (p PingvinKL) Update() {
func (p PingvinKL) ReadCoil(n uint16) []byte { func (p PingvinKL) ReadCoil(n uint16) []byte {
handler := p.getHandler() handler := p.getHandler()
p.buslock.Lock()
err := handler.Connect() err := handler.Connect()
if err != nil { if err != nil {
log.Fatal("ReadCoil: handler.Connect: ", err) log.Fatal("ReadCoil: handler.Connect: ", err)
@ -102,15 +107,18 @@ func (p PingvinKL) ReadCoil(n uint16) []byte {
defer handler.Close() defer handler.Close()
client := modbus.NewClient(handler) client := modbus.NewClient(handler)
results, err := client.ReadCoils(n, 1) results, err := client.ReadCoils(n, 1)
p.buslock.Unlock()
if err != nil { if err != nil {
log.Fatal("ReadCoil: client.ReadCoils", err) log.Fatal("ReadCoil: client.ReadCoils", err)
} }
p.Coils[n].Value = results[0] == 1
return results return results
} }
// create a PingvinKL struct, read coils and registers from CSVs // create a PingvinKL struct, read coils and registers from CSVs
func New() PingvinKL { func New() PingvinKL {
pingvin := PingvinKL{} pingvin := PingvinKL{}
pingvin.buslock = &sync.Mutex{}
coilData := readCsvLines("coils.csv") coilData := readCsvLines("coils.csv")
for i := 0; i < len(coilData); i++ { for i := 0; i < len(coilData); i++ {
pingvin.Coils = append(pingvin.Coils, newCoil(coilData[i][1], coilData[i][2])) pingvin.Coils = append(pingvin.Coils, newCoil(coilData[i][1], coilData[i][2]))