golang sync.pool

 

 

这个例子，理解一下

 

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package main   import (     "fmt"     "sync"     "time" )   // Pool for our struct A var pool *sync.Pool   // A dummy struct with a member type A struct {     Name string }   // Func to init pool func initPool() {     pool = &sync.Pool {         New: func()interface{} {             fmt.Println("Returning new A")             return new(A)         },     } }   // Main func func main() {     // Initializing pool     initPool()     // Get hold of instance one     one := pool.Get().(*A)     one.Name = "first"     fmt.Printf("one.Name = %s\n", one.Name)     // Pass one to a go routine that just stops for 10 second     // Assume that this could be any i/o bound task, something like an API call     go func(o *A) {         fmt.Printf("Before pool.Put\no.Name = %s\n", o.Name)         time.Sleep(10 * time.Second)         fmt.Printf("After pool.Put With same object\no.Name = %s\n", o.Name)     }(one)     // Main routine performs some operations for 1 second     time.Sleep(1 * time.Second)     // Till then your main routine submits back the main object     pool.Put(one)     two := pool.Get().(*A)     two.Name = "second"     fmt.Printf("two.Name = %s\n", two.Name)     // Just for the sake of demo wait for next 15 seconds     time.Sleep(15 * time.Second)    }