libgo/go/sync/runtime.go

   1 // Copyright 2012 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 sync
   6
   7 import "unsafe"
   8
   9 // defined in package runtime
  10
  11 // Semacquire waits until *s > 0 and then atomically decrements it.
  12 // It is intended as a simple sleep primitive for use by the synchronization
  13 // library and should not be used directly.
  14 func runtime_Semacquire(s *uint32)
  15
  16 // Semrelease atomically increments *s and notifies a waiting goroutine
  17 // if one is blocked in Semacquire.
  18 // It is intended as a simple wakeup primitive for use by the synchronization
  19 // library and should not be used directly.
  20 func runtime_Semrelease(s *uint32)
  21
  22 // Approximation of notifyList in runtime/sema.go. Size and alignment must
  23 // agree.
  24 type notifyList struct {
  25         wait   uint32
  26         notify uint32
  27         lock   uintptr
  28         head   unsafe.Pointer
  29         tail   unsafe.Pointer
  30 }
  31
  32 // See runtime/sema.go for documentation.
  33 func runtime_notifyListAdd(l *notifyList) uint32
  34
  35 // See runtime/sema.go for documentation.
  36 func runtime_notifyListWait(l *notifyList, t uint32)
  37
  38 // See runtime/sema.go for documentation.
  39 func runtime_notifyListNotifyAll(l *notifyList)
  40
  41 // See runtime/sema.go for documentation.
  42 func runtime_notifyListNotifyOne(l *notifyList)
  43
  44 // Ensure that sync and runtime agree on size of notifyList.
  45 func runtime_notifyListCheck(size uintptr)
  46 func init() {
  47         var n notifyList
  48         runtime_notifyListCheck(unsafe.Sizeof(n))
  49 }
  50
  51 // Active spinning runtime support.
  52 // runtime_canSpin returns true is spinning makes sense at the moment.
  53 func runtime_canSpin(i int) bool
  54
  55 // runtime_doSpin does active spinning.
  56 func runtime_doSpin()