Go-标准库-runtime（二）

package main

import (
	"fmt"
	"runtime"
)

func main() {
	var mem runtime.MemStats
	runtime.ReadMemStats(&mem)
	fmt.Println("Before allocation:")
	fmt.Printf("Alloc = %v MiB\n", mem.Alloc/1024/1024)
	fmt.Printf("TotalAlloc = %v MiB\n", mem.TotalAlloc/1024/1024)
	fmt.Printf("HeapAlloc = %v MiB\n", mem.HeapAlloc/1024/1024)
	fmt.Printf("HeapSys = %v MiB\n", mem.HeapSys/1024/1024)

	data := make([]byte, 1024*1024*1024)
	fmt.Println("After allocation:")
	runtime.ReadMemStats(&mem)
	fmt.Printf("Alloc = %v MiB\n", mem.Alloc/1024/1024)
	fmt.Printf("TotalAlloc = %v MiB\n", mem.TotalAlloc/1024/1024)
	fmt.Printf("HeapAlloc = %v MiB\n", mem.HeapAlloc/1024/1024)
	fmt.Printf("HeapSys = %v MiB\n", mem.HeapSys/1024/1024)

	data = nil
	runtime.GC()
	fmt.Println("After GC:")
	runtime.ReadMemStats(&mem)
	fmt.Printf("Alloc = %v MiB\n", mem.Alloc/1024/1024)
	fmt.Printf("TotalAlloc = %v MiB\n", mem.TotalAlloc/1024/1024)
	fmt.Printf("HeapAlloc = %v MiB\n", mem.HeapAlloc/1024/1024)
	fmt.Printf("HeapSys = %v MiB\n", mem.HeapSys/1024/1024)
}