Prevent concurrent read/write to status map

1 files changed, 16 insertions, 5 deletions

diff --git a/status/00-status.go b/status/00-status.go
index bfd7bb9..109c49c 100644
--- a/status/00-status.go
+++ b/status/00-status.go
@@ -3,6 +3,7 @@ package status // import "hhvn.uk/hbspbar/status"
 import (
 	"fmt"
 	"time"
+	"sync"
 	"image"
 	"image/color"
 
@@ -15,14 +16,21 @@ var NewBlocks = make(chan *Blocks)
 var updates   = make(chan *status)
 var statusid  = make(map[string]int)
 
-type Blocks map[int]*status
+type Blocks struct {
+	l *sync.RWMutex
+	m map[int]*status
+}
 
 func (b *Blocks) Len() int {
-	return len(map[int]*status(*b))
+	b.l.RLock()
+	defer b.l.RUnlock()
+	return len(b.m)
 }
 
 func (b *Blocks) Get(i int) (s *status, ok bool) {
-	s, ok = (map[int]*status(*b))[i]
+	b.l.RLock()
+	defer b.l.RUnlock()
+	s, ok = b.m[i]
 	return
 }
 
@@ -33,16 +41,19 @@ type status struct {
 }
 
 func init() {
+	var mutex sync.RWMutex
 	status := make(map[int]*status)
+	b      := &Blocks{&mutex, status}
 
 	go func() {
 		for s := range updates {
 			id := statusid[s.Name]
 
+			mutex.Lock()
 			status[id] = s
+			mutex.Unlock()
 
-			b := Blocks(status)
-			NewBlocks <- &b
+			NewBlocks <- b
 		}
 	}()
 }