mirror of https://go.googlesource.com/go
42 lines
851 B
Go
42 lines
851 B
Go
// run
|
|
|
|
//go:build amd64
|
|
|
|
// Copyright 2016 The Go Authors. All rights reserved.
|
|
// Use of this source code is governed by a BSD-style
|
|
// license that can be found in the LICENSE file.
|
|
|
|
package main
|
|
|
|
import "runtime"
|
|
|
|
type big [10 << 20]byte
|
|
|
|
func f(x *big, start int64) {
|
|
if delta := inuse() - start; delta < 9<<20 {
|
|
println("after alloc: expected delta at least 9MB, got: ", delta)
|
|
}
|
|
runtime.KeepAlive(x)
|
|
x = nil
|
|
if delta := inuse() - start; delta > 1<<20 {
|
|
println("after drop: expected delta below 1MB, got: ", delta)
|
|
}
|
|
x = new(big)
|
|
if delta := inuse() - start; delta < 9<<20 {
|
|
println("second alloc: expected delta at least 9MB, got: ", delta)
|
|
}
|
|
runtime.KeepAlive(x)
|
|
}
|
|
|
|
func main() {
|
|
x := inuse()
|
|
f(new(big), x)
|
|
}
|
|
|
|
func inuse() int64 {
|
|
runtime.GC()
|
|
var st runtime.MemStats
|
|
runtime.ReadMemStats(&st)
|
|
return int64(st.Alloc)
|
|
}
|