libgo/go/runtime/mallocrep.go

   1 // Copyright 2009 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 // Repeated malloc test.
   6
   7 // +build ignore
   8
   9 package main
  10
  11 import (
  12         "flag"
  13         "runtime"
  14 )
  15
  16 var chatty = flag.Bool("v", false, "chatty")
  17
  18 var oldsys uint64
  19 var memstats runtime.MemStats
  20
  21 func bigger() {
  22         st := &memstats
  23         runtime.ReadMemStats(st)
  24         if oldsys < st.Sys {
  25                 oldsys = st.Sys
  26                 if *chatty {
  27                         println(st.Sys, " system bytes for ", st.Alloc, " Go bytes")
  28                 }
  29                 if st.Sys > 1e9 {
  30                         println("too big")
  31                         panic("fail")
  32                 }
  33         }
  34 }
  35
  36 func main() {
  37         runtime.GC()                    // clean up garbage from init
  38         runtime.ReadMemStats(&memstats) // first call can do some allocations
  39         runtime.MemProfileRate = 0      // disable profiler
  40         stacks := memstats.Alloc        // ignore stacks
  41         flag.Parse()
  42         for i := 0; i < 1<<7; i++ {
  43                 for j := 1; j <= 1<<22; j <<= 1 {
  44                         if i == 0 && *chatty {
  45                                 println("First alloc:", j)
  46                         }
  47                         if a := memstats.Alloc - stacks; a != 0 {
  48                                 println("no allocations but stats report", a, "bytes allocated")
  49                                 panic("fail")
  50                         }
  51                         b := runtime.Alloc(uintptr(j))
  52                         runtime.ReadMemStats(&memstats)
  53                         during := memstats.Alloc - stacks
  54                         runtime.Free(b)
  55                         runtime.ReadMemStats(&memstats)
  56                         if a := memstats.Alloc - stacks; a != 0 {
  57                                 println("allocated ", j, ": wrong stats: during=", during, " after=", a, " (want 0)")
  58                                 panic("fail")
  59                         }
  60                         bigger()
  61                 }
  62                 if i%(1<<10) == 0 && *chatty {
  63                         println(i)
  64                 }
  65                 if i == 0 {
  66                         if *chatty {
  67                                 println("Primed", i)
  68                         }
  69                         //      runtime.frozen = true
  70                 }
  71         }
  72 }