From 5f48a845b14f742a6055d69520e9d05dc17187bd Mon Sep 17 00:00:00 2001
From: matst80 <mats.tornberg@gmail.com>
Date: Mon, 11 Nov 2024 17:28:49 +0100
Subject: [PATCH] add some locks

---
 cart-grain.go | 9 +++++++++
 grain-pool.go | 8 ++++++++
 2 files changed, 17 insertions(+)

diff --git a/cart-grain.go b/cart-grain.go
index ca97cc4..447f032 100644
--- a/cart-grain.go
+++ b/cart-grain.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"slices"
+	"sync"
 	"time"
 
 	messages "git.tornberg.me/go-cart-actor/proto"
@@ -41,6 +42,7 @@ type CartDelivery struct {
 }
 
 type CartGrain struct {
+	mu              sync.RWMutex
 	lastItemId      int
 	lastDeliveryId  int
 	storageMessages []Message
@@ -111,6 +113,8 @@ func (c *CartGrain) AddItem(sku string, qty int) ([]byte, error) {
 func (c *CartGrain) GetStorageMessage(since int64) []StorableMessage {
 
 	ret := make([]StorableMessage, 0)
+	c.mu.RLock()
+	defer c.mu.RUnlock()
 	for _, message := range c.storageMessages {
 		if *message.TimeStamp > since {
 			ret = append(ret, message)
@@ -189,6 +193,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) ([]byte, erro
 				}
 			}
 			if !found {
+				c.mu.Lock()
 				c.lastItemId++
 				c.Items = append(c.Items, &CartItem{
 					Id:       c.lastItemId,
@@ -199,6 +204,7 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) ([]byte, erro
 					Image:    msg.Image,
 				})
 				c.TotalPrice += msg.Price * int64(msg.Quantity)
+				c.mu.Unlock()
 			}
 		}
 	case ChangeQuantityType:
@@ -269,8 +275,11 @@ func (c *CartGrain) HandleMessage(message *Message, isReplay bool) ([]byte, erro
 	if err != nil {
 		return nil, err
 	}
+
 	if !isReplay {
+		c.mu.Lock()
 		c.storageMessages = append(c.storageMessages, *message)
+		c.mu.Unlock()
 	}
 	return json.Marshal(c)
 }
diff --git a/grain-pool.go b/grain-pool.go
index 1a8827c..9a26804 100644
--- a/grain-pool.go
+++ b/grain-pool.go
@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
+	"sync"
 	"time"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -36,6 +37,7 @@ type Ttl struct {
 }
 
 type GrainLocalPool struct {
+	mu       sync.RWMutex
 	grains   map[CartId]*CartGrain
 	expiry   []Ttl
 	spawn    func(id CartId) (*CartGrain, error)
@@ -62,6 +64,8 @@ func NewGrainLocalPool(size int, ttl time.Duration, spawn func(id CartId) (*Cart
 }
 
 func (p *GrainLocalPool) SetAvailable(availableWithLastChangeUnix map[CartId]int64) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
 	for id := range availableWithLastChangeUnix {
 		if _, ok := p.grains[id]; !ok {
 			p.grains[id] = nil
@@ -76,6 +80,8 @@ func (p *GrainLocalPool) SetAvailable(availableWithLastChangeUnix map[CartId]int
 func (p *GrainLocalPool) Purge() {
 	lastChangeTime := time.Now().Add(-p.Ttl)
 	keepChanged := lastChangeTime.Unix()
+	p.mu.Lock()
+	defer p.mu.Unlock()
 	for i := 0; i < len(p.expiry); i++ {
 		item := p.expiry[i]
 		if item.Expires.Before(time.Now()) {
@@ -100,6 +106,8 @@ func (p *GrainLocalPool) GetGrains() map[CartId]*CartGrain {
 
 func (p *GrainLocalPool) GetGrain(id CartId) (*CartGrain, error) {
 	var err error
+	p.mu.RLock()
+	defer p.mu.RUnlock()
 	grain, ok := p.grains[id]
 	grainLookups.Inc()
 	if grain == nil || !ok {