test/gc2.go

   1 // run
   2
   3 //go:build !nacl && !js
   4
   5 // Copyright 2011 The Go Authors. All rights reserved.
   6 // Use of this source code is governed by a BSD-style
   7 // license that can be found in the LICENSE file.
   8
   9 // Test that buffered channels are garbage collected properly.
  10 // An interesting case because they have finalizers and used to
  11 // have self loops that kept them from being collected.
  12 // (Cyclic data with finalizers is never finalized, nor collected.)
  13
  14 package main
  15
  16 import (
  17         "fmt"
  18         "os"
  19         "runtime"
  20 )
  21
  22 func main() {
  23         const N = 10000
  24         st := new(runtime.MemStats)
  25         memstats := new(runtime.MemStats)
  26         runtime.ReadMemStats(st)
  27         for i := 0; i < N; i++ {
  28                 c := make(chan int, 10)
  29                 _ = c
  30                 if i%100 == 0 {
  31                         for j := 0; j < 4; j++ {
  32                                 runtime.GC()
  33                                 runtime.Gosched()
  34                                 runtime.GC()
  35                                 runtime.Gosched()
  36                         }
  37                 }
  38         }
  39
  40         runtime.ReadMemStats(memstats)
  41         obj := int64(memstats.HeapObjects - st.HeapObjects)
  42         if obj > N/5 {
  43                 fmt.Println("too many objects left:", obj)
  44                 os.Exit(1)
  45         }
  46 }