sync.mutex start

.idea/vcs.xml

@@ -2,5 +2,6 @@
 <project version="4">
   <component name="VcsDirectoryMappings">
     <mapping directory="$PROJECT_DIR$" vcs="Git" />
+    <mapping directory="$PROJECT_DIR$/logging" vcs="Git" />
   </component>
 </project>

sync/mutex.go

@@ -0,0 +1,29 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+)
+
+// 互斥锁
+var x = 0
+
+var wg sync.WaitGroup
+var lock sync.Mutex
+
+func add() {
+	for i := 0; i < 5000; i++ {
+		lock.Lock()
+		x = x + 1
+		lock.Unlock()
+	}
+	wg.Done()
+}
+
+func main() {
+	wg.Add(2)
+	go add()
+	go add()
+	wg.Wait()
+	fmt.Println(x)
+}