github.com/qiuhoude/go-web@v0.0.0-20220223060959-ab545e78f20d/prepare/14_concurrent/mutex/main.go (about)

     1  package main
     2  
     3  import (
     4  	"fmt"
     5  	"sync"
     6  )
     7  
     8  /*
     9  A: 不能编译
    10  B: 输出 main --> A --> B --> C
    11  C: 输出 main
    12  D: panic 答案deadlock!
    13  */
    14  var mu sync.Mutex
    15  var chain string
    16  
    17  func main() {
    18  	chain = "main"
    19  	A()
    20  	fmt.Println(chain)
    21  }
    22  func A() {
    23  	mu.Lock()
    24  	defer mu.Unlock()
    25  	chain = chain + " --> A"
    26  	B()
    27  }
    28  func B() {
    29  	chain = chain + " --> B"
    30  	C()
    31  }
    32  func C() {
    33  	mu.Lock()
    34  	defer mu.Unlock()
    35  	chain = chain + " --> C"
    36  }