defer wg.Done() worker(i) }() } wg.Wait() } 注意事项 defer后面跟的必须是函数或者方法调用,defer后面的表达式不能直接加括号。 defer (fmt.Println(1))//编译报错,因为defer后面跟的表达式不能加括号defer fmt.Println(1)//编译正确,函数最后输出 被defer的函数的参数在定
var wg sync.WaitGroup func main() { for i := 0; i < 10; i++ { wg.Add(1) go f1(i) } wg.Wait() } sync.Mutex 互斥锁 package main import ( "fmt" "sync" ) var x = 0 var wg sync.WaitGroup var mu sync.Mutex func add() { defer wg.Done() for i := 0; i < 500000;...
wg.Add(1) go func() { defer wg.Done() increment() }() } wg.Wait() fmt.Println("Counter:", counter) }
func processChunk(chunk []int64, wg*sync.WaitGroup,failedList *[]int64) { defer wg.Done() fmt.Println("failedList===open1===", failedList)for_, uid :=range chunk {//将失败的UIDs添加到failedList*failedList = append(*failedList, uid)// 关键位置 } fmt.Println("failedList===open2==...
wg.Wait() } WithValue (key值不能为基础类型,应该用用户自定义的类型) package main import ( "context" "fmt" "sync" "time" ) type cjp string var wg sync.WaitGroup func f(ctx context.Context) { defer wg.Done() LOOP: for { fmt.Println(ctx.Value(cjp("mt"))) ...
defer wg1.Done() line = <row from f> result = go processRow(line) newFile.Println(result) // Write new processed line to newFile wg2.Wait() newFile.Close() } func main() { for each f logfile { go processFile(f) } wg1.Wait() } 所以,想法是我同时处理这 5 个文件,然后每个文...
varcounter=0funcincrement(chchanint,wg*sync.WaitGroup){deferwg.Done()// 标记该 goroutine 完成...
1.2defer的执行顺序 如果有多个defer语句,它们会按照后进先出(LIFO)的顺序执行。 funcmain(){deferfmt.Println("First")deferfmt.Println("Second")deferfmt.Println("Third") fmt.Println("Hello") } AI代码助手复制代码 输出结果: Hello ThirdSecondFirst ...
= nil { fmt.Println(err) return } chunks[i] = Chunk{Index: int64(i), Data: data} } // 并发上传文件块 wg := sync.WaitGroup{} for i, chunk := range chunks { wg.Add(1) go func(index int, data []byte) { defer wg.Done() key := fmt.Sprintf("%v/%v/%v", handler.File...
defer wg.Done() increment() }() } wg.Wait() fmt.Println("Counter:", counter) } 读写锁(RWMutex):适用于读多写少的场景,允许多个 Goroutine 同时进行读操作,但写操作时会独占资源。 原子操作:Go 语言的sync/atomic包提供了原子操作函数,用于对整数类型进行原子性的读写操作,避免了锁的开销。