libgo/go/runtime/debug.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 (
   8         "runtime/internal/atomic"
   9         "unsafe"
  10 )
  11
  12 // GOMAXPROCS sets the maximum number of CPUs that can be executing
  13 // simultaneously and returns the previous setting. If n < 1, it does not
  14 // change the current setting.
  15 // The number of logical CPUs on the local machine can be queried with NumCPU.
  16 // This call will go away when the scheduler improves.
  17 func GOMAXPROCS(n int) int {
  18         if n > _MaxGomaxprocs {
  19                 n = _MaxGomaxprocs
  20         }
  21         lock(&sched.lock)
  22         ret := int(gomaxprocs)
  23         unlock(&sched.lock)
  24         if n <= 0 || n == ret {
  25                 return ret
  26         }
  27
  28         stopTheWorld("GOMAXPROCS")
  29
  30         // newprocs will be processed by startTheWorld
  31         newprocs = int32(n)
  32
  33         startTheWorld()
  34         return ret
  35 }
  36
  37 // NumCPU returns the number of logical CPUs usable by the current process.
  38 //
  39 // The set of available CPUs is checked by querying the operating system
  40 // at process startup. Changes to operating system CPU allocation after
  41 // process startup are not reflected.
  42 func NumCPU() int {
  43         return int(ncpu)
  44 }
  45
  46 // NumCgoCall returns the number of cgo calls made by the current process.
  47 func NumCgoCall() int64 {
  48         var n int64
  49         for mp := (*m)(atomic.Loadp(unsafe.Pointer(&allm))); mp != nil; mp = mp.alllink {
  50                 n += int64(mp.ncgocall)
  51         }
  52         return n
  53 }
  54
  55 // NumGoroutine returns the number of goroutines that currently exist.
  56 func NumGoroutine() int {
  57         waitForSystemGoroutines()
  58         return int(gcount())
  59 }
  60
  61 // Get field tracking information.  Only fields with a tag go:"track"
  62 // are tracked.  This function will add every such field that is
  63 // referenced to the map.  The keys in the map will be
  64 // PkgPath.Name.FieldName.  The value will be true for each field
  65 // added.
  66 func Fieldtrack(map[string]bool)