CODEWITHSUNDEEP
goatomic
recolic
recolic

Reputation: 626

sync/atomic StoreInt32 strange behavior

This code is simplified and describes my problem. It seems that atomic.StoreInt32 not work but I'm not sure why.

package main
import (
    "fmt"
    "sync/atomic"
)

type slave struct {
    failed int32
}
func NewSlave() slave {
    return slave{0}
}
func (worker slave) Fail() {
    atomic.StoreInt32(&worker.failed, 1) // Here's the problem.
}
func (worker slave) IsFailed() bool {
    failed := atomic.LoadInt32(&worker.failed) == 1
    return failed
}
func (worker slave) FailureReset() {
    atomic.StoreInt32(&worker.failed, 0)
}

func main() {
    s := NewSlave()
    fmt.Println(s.IsFailed())
    s.Fail()
    fmt.Println(s.IsFailed())
    s.FailureReset()
    fmt.Println(s.IsFailed())
}

->output:

false 0
false 0
false 0

->tested on:

recolic@RECOLICPC ~/tmp> go version
go version go1.9.2 linux/amd64
recolic@RECOLICPC ~/tmp> uname -a
Linux RECOLICPC 4.13.12-1-ARCH #1 SMP PREEMPT Wed Nov 8 11:54:06 CET 2017 x86_64 GNU/Linux

I've read: usage golang atomic LoadInt32/StoreInt32 (64)

Upvotes: 0

Views: 230

Answers (1)

Andy Schweig
Andy Schweig

Reputation: 6739

You need to make your methods take a pointer receiver. As written, the functions are operating on a copy of your worker, so the worker used to invoke the method is not changed. Define the methods like this:

func (worker *slave) Fail() {
    // ...
}

Upvotes: 1

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