go/test/chan/select2.go
Emmanuel Odeke 53fd522c0d all: make copyright headers consistent with one space after period
Follows suit with https://go-review.googlesource.com/#/c/20111.

Generated by running
$ grep -R 'Go Authors.  All' * | cut -d":" -f1 | while read F;do perl -pi -e 's/Go
Authors.  All/Go Authors. All/g' $F;done

The code in cmd/internal/unvendor wasn't changed.

Fixes #15213

Change-Id: I4f235cee0a62ec435f9e8540a1ec08ae03b1a75f
Reviewed-on: https://go-review.googlesource.com/21819
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2016-05-02 13:43:18 +00:00

54 lines
1 KiB
Go

// run
// Copyright 2010 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.
// Test that selects do not consume undue memory.
package main
import "runtime"
func sender(c chan int, n int) {
for i := 0; i < n; i++ {
c <- 1
}
}
func receiver(c, dummy chan int, n int) {
for i := 0; i < n; i++ {
select {
case <-c:
// nothing
case <-dummy:
panic("dummy")
}
}
}
func main() {
runtime.MemProfileRate = 0
c := make(chan int)
dummy := make(chan int)
// warm up
go sender(c, 100000)
receiver(c, dummy, 100000)
runtime.GC()
memstats := new(runtime.MemStats)
runtime.ReadMemStats(memstats)
alloc := memstats.Alloc
// second time shouldn't increase footprint by much
go sender(c, 100000)
receiver(c, dummy, 100000)
runtime.GC()
runtime.ReadMemStats(memstats)
// Be careful to avoid wraparound.
if memstats.Alloc > alloc && memstats.Alloc-alloc > 1.1e5 {
println("BUG: too much memory for 100,000 selects:", memstats.Alloc-alloc)
}
}