race condition demo update

tmpbook · tmpbook · commit ed7e50306a76 · 2018-01-22T23:22:59.000+08:00
diff --git a/race-condition/1000Goroutines/main.go b/race-condition/1000Goroutines/main.go
@@ -5,7 +5,7 @@ import (
 	"sync"
 )
 
-// N 是内存里的一个数子
+// N 是内存里的一个对象
 var (
 	N         = 0
 	waitgroup sync.WaitGroup
diff --git a/race-condition/2Goroutines/main.go b/race-condition/2Goroutines/main.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+// N 是内存里的一个对象
+var (
+	N         = 0
+	waitgroup sync.WaitGroup
+)
+
+func counter(number *int) {
+	for i := 0; i < 1000; i++ {
+		*number++
+	}
+	waitgroup.Done()
+}
+
+func main() {
+	waitgroup.Add(2)
+	go counter(&N)
+	go counter(&N)
+
+	waitgroup.Wait()
+	fmt.Println(N)
+}
