Golang 垃圾回收和 SetFinalizer

package main

import (
    "fmt"
    "runtime"
    "sync"
    "time"
)

type SampleResource struct {
    id   int
    done chan bool
}

func NewSampleResource(id int) *SampleResource {
    return &SampleResource{
        id:   id,
        done: make(chan bool),
    }
}

func (r *SampleResource) Close() {
    fmt.Printf("SampleResource %d closed\n", r.id)
    close(r.done)
}

func (r *SampleResource) Stop() {
    fmt.Printf("SampleResource %d stopped\n", r.id)
}

func main() {
    runtime.GOMAXPROCS(1)

    var wg sync.WaitGroup
    wg.Add(1)

    go func() {
        defer wg.Done()
        r := NewSampleResource(1)

        defer r.Close()
        // 设置 finalizer 函数
        runtime.SetFinalizer(r, (*SampleResource).Stop)

        <-r.done
    }()

    wg.Wait()
    fmt.Println("main exit")
}