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// run
// 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"
func main() {
{
x := inuse()
c := make(chan []byte, 10)
c <- make([]byte, 10<<20)
close(c)
f1(c, x)
}
{
x := inuse()
c := make(chan []byte, 10)
c <- make([]byte, 10<<20)
close(c)
f2(c, x)
}
}
func f1(c chan []byte, start int64) {
for x := range c {
if delta := inuse() - start; delta < 9<<20 {
println("BUG: f1: after alloc: expected delta at least 9MB, got: ", delta)
println(x)
}
x = nil
if delta := inuse() - start; delta > 1<<20 {
println("BUG: f1: after alloc: expected delta below 1MB, got: ", delta)
println(x)
}
}
}
func f2(c chan []byte, start int64) {
for {
x, ok := <-c
if !ok {
break
}
if delta := inuse() - start; delta < 9<<20 {
println("BUG: f2: after alloc: expected delta at least 9MB, got: ", delta)
println(x)
}
x = nil
if delta := inuse() - start; delta > 1<<20 {
println("BUG: f2: after alloc: expected delta below 1MB, got: ", delta)
println(x)
}
}
}
func inuse() int64 {
runtime.GC()
var st runtime.MemStats
runtime.ReadMemStats(&st)
return int64(st.Alloc)
}
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