weak demo weak demo

main.go

package main

import (
	"fmt"
	"runtime"
	"strings"
	"time"
	"unsafe"
	"weak"
)

func main() {
	originalObject := "Hello, World!"
	runtime.AddCleanup(&originalObject, func(s int64) {
		fmt.Println("originalObject clean at: ", s)
	}, time.Now().Unix())
	weakPtr := weak.Make(&originalObject)
	fmt.Println(fmt.Sprintf("originalObject:addr %x", &originalObject))
	fmt.Println(fmt.Sprintf("weakPtr addr:%x,size:%d", weakPtr, unsafe.Sizeof(weakPtr)))
	runtime.GC()
	time.Sleep(1 * time.Millisecond)
	value := weakPtr.Value()
	if value != nil && strings.Contains(*value, originalObject) {
		fmt.Println("First GC :value: ", *value)
	} else {
		fmt.Println("first gc. Weak reference value is nil")
	}
	runtime.GC()
	time.Sleep(1 * time.Millisecond)
	value = weakPtr.Value()
	if value != nil {
		fmt.Println("Second GC", *value)
	} else {
		fmt.Println("Second GC: Weak reference value is nil")
	}
}