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go/test/init1.go
Brad Fitzpatrick b5b11bdbc6 test: deflake init1.go test, tighten its bounds
Per the comment at top, this test is about whether the GC runs during
init, but it was testing more than that, and testing how much the GC
collected in a certain amount of time.

Instead, loosen this test to just see whether it ran at all and not
how well it did.

Fixes #9848

Change-Id: I31da7dd769140d7b49aa6c149a543fae6076aa5e
Reviewed-on: https://go-review.googlesource.com/4820
Reviewed-by: Rick Hudson <rlh@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
2015-02-13 22:13:56 +00:00

54 lines
1.1 KiB
Go

// run
// Copyright 2011 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 goroutines and garbage collection run during init.
package main
import "runtime"
var x []byte
func init() {
c := make(chan int)
go send(c)
<-c
const N = 1000
const MB = 1 << 20
b := make([]byte, MB)
for i := range b {
b[i] = byte(i%10 + '0')
}
s := string(b)
memstats := new(runtime.MemStats)
runtime.ReadMemStats(memstats)
sys, numGC := memstats.Sys, memstats.NumGC
// Generate 1,000 MB of garbage, only retaining 1 MB total.
for i := 0; i < N; i++ {
x = []byte(s)
}
// Verify that the garbage collector ran by seeing if we
// allocated fewer than N*MB bytes from the system.
runtime.ReadMemStats(memstats)
sys1, numGC1 := memstats.Sys, memstats.NumGC
if sys1-sys >= N*MB || numGC1 == numGC {
println("allocated 1000 chunks of", MB, "and used ", sys1-sys, "memory")
println("numGC went", numGC, "to", numGC)
panic("init1")
}
}
func send(c chan int) {
c <- 1
}
func main() {
}