statefule goroutines _ golang

這是一個建立於 的文章，其中的資訊可能已經有所發展或是發生改變。

In the previous example we used explicit locking with mutexes to synchronize access to shared state across multiple goroutines. Another option is to use the built-in synchronization features of goroutines and channels to achieve the same result. This channel-based approach aligns with Go's ideas of sharing memory by communivating and having each piece of data owned by exactly 1 goroutine

package mainimport (    "fmt"    "math/rand"    "sync/atomic"    "time")type read0p struct {    key  int    resp chan int}type write0p struct {    key  int    val  int    resp chan bool}func main() {    var ops int64 = 0    reads := make(chan *read0p)    writes := make(chan *write0p)    go func() {        var state = make(map[int]int)        for {            select {            case read := <-reads:                read.resp <- state[read.key]            case write := <-writes:                state[write.key] = write.val                write.resp <- true            }        }    }()    for r := 0; r < 100; r++ {        go func() {            for {                read := &read0p{                    key:  rand.Intn(5),                    resp: make(chan int),                }                reads <- read                fmt.Println("<-read.resp:", <-read.resp)                atomic.AddInt64(&ops, 1)            }        }()    }    for w := 0; w < 10; w++ {        go func() {            for {                write := &write0p{                    key:  rand.Intn(5),                    val:  rand.Intn(100),                    resp: make(chan bool),                }                writes <- write                <-write.resp                atomic.AddInt64(&ops, 1)            }        }()    }    time.Sleep(time.Second)    opsFinal := atomic.LoadInt64(&ops)    fmt.Println("ops:", opsFinal)}

ops: 329696

總結 :

　　1 : atomic.AddInt64 原子性的增加一個值