1 // run 2 3 // Copyright 2011 The Go Authors. All rights reserved. 4 // Use of this source code is governed by a BSD-style 5 // license that can be found in the LICENSE file. 6 7 // Test that goroutines and garbage collection run during init. 8 9 package main 10 11 import "runtime" 12 13 var x []byte 14 15 func init() { 16 c := make(chan int) 17 go send(c) 18 <-c 19 20 const N = 1000 21 const MB = 1 << 20 22 b := make([]byte, MB) 23 for i := range b { 24 b[i] = byte(i%10 + '0') 25 } 26 s := string(b) 27 28 memstats := new(runtime.MemStats) 29 runtime.ReadMemStats(memstats) 30 sys, numGC := memstats.Sys, memstats.NumGC 31 32 // Generate 1,000 MB of garbage, only retaining 1 MB total. 33 for i := 0; i < N; i++ { 34 x = []byte(s) 35 } 36 37 // Verify that the garbage collector ran by seeing if we 38 // allocated fewer than N*MB bytes from the system. 39 runtime.ReadMemStats(memstats) 40 sys1, numGC1 := memstats.Sys, memstats.NumGC 41 if sys1-sys >= N*MB || numGC1 == numGC { 42 println("allocated 1000 chunks of", MB, "and used ", sys1-sys, "memory") 43 println("numGC went", numGC, "to", numGC1) 44 panic("init1") 45 } 46 } 47 48 func send(c chan int) { 49 c <- 1 50 } 51 52 func main() { 53 } 54
