libgo/go/runtime/mem.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 package runtime
   6
   7 import "unsafe"
   8
   9 // Note: the MemStats struct should be kept in sync with
  10 // struct MStats in malloc.h
  11
  12 // A MemStats records statistics about the memory allocator.
  13 type MemStats struct {
  14         // General statistics.
  15         Alloc      uint64 // bytes allocated and still in use
  16         TotalAlloc uint64 // bytes allocated (even if freed)
  17         Sys        uint64 // bytes obtained from system (sum of XxxSys below)
  18         Lookups    uint64 // number of pointer lookups
  19         Mallocs    uint64 // number of mallocs
  20         Frees      uint64 // number of frees
  21
  22         // Main allocation heap statistics.
  23         HeapAlloc    uint64 // bytes allocated and still in use
  24         HeapSys      uint64 // bytes obtained from system
  25         HeapIdle     uint64 // bytes in idle spans
  26         HeapInuse    uint64 // bytes in non-idle span
  27         HeapReleased uint64 // bytes released to the OS
  28         HeapObjects  uint64 // total number of allocated objects
  29
  30         // Low-level fixed-size structure allocator statistics.
  31         //      Inuse is bytes used now.
  32         //      Sys is bytes obtained from system.
  33         StackInuse  uint64 // bootstrap stacks
  34         StackSys    uint64
  35         MSpanInuse  uint64 // mspan structures
  36         MSpanSys    uint64
  37         MCacheInuse uint64 // mcache structures
  38         MCacheSys   uint64
  39         BuckHashSys uint64 // profiling bucket hash table
  40         GCSys       uint64 // GC metadata
  41         OtherSys    uint64 // other system allocations
  42
  43         // Garbage collector statistics.
  44         NextGC       uint64 // next run in HeapAlloc time (bytes)
  45         LastGC       uint64 // last run in absolute time (ns)
  46         PauseTotalNs uint64
  47         PauseNs      [256]uint64 // circular buffer of recent GC pause times, most recent at [(NumGC+255)%256]
  48         NumGC        uint32
  49         EnableGC     bool
  50         DebugGC      bool
  51
  52         // Per-size allocation statistics.
  53         // 61 is NumSizeClasses in the C code.
  54         BySize [61]struct {
  55                 Size    uint32
  56                 Mallocs uint64
  57                 Frees   uint64
  58         }
  59 }
  60
  61 var Sizeof_C_MStats uintptr // filled in by malloc.goc
  62
  63 func init() {
  64         var memStats MemStats
  65         if Sizeof_C_MStats != unsafe.Sizeof(memStats) {
  66                 println(Sizeof_C_MStats, unsafe.Sizeof(memStats))
  67                 panic("MStats vs MemStatsType size mismatch")
  68         }
  69 }
  70
  71 // ReadMemStats populates m with memory allocator statistics.
  72 func ReadMemStats(m *MemStats)
  73
  74 // GC runs a garbage collection.
  75 func GC()