base/mac/scoped_mach_port.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef BASE_MAC_SCOPED_MACH_PORT_H_
   6 #define BASE_MAC_SCOPED_MACH_PORT_H_
   7
   8 #include <mach/mach.h>
   9
  10 #include "base/base_export.h"
  11 #include "base/scoped_generic.h"
  12
  13 namespace base {
  14 namespace mac {
  15
  16 namespace internal {
  17
  18 struct BASE_EXPORT SendRightTraits {
  19   static mach_port_t InvalidValue() {
  20     return MACH_PORT_NULL;
  21   }
  22
  23   static void Free(mach_port_t port);
  24 };
  25
  26 struct BASE_EXPORT ReceiveRightTraits {
  27   static mach_port_t InvalidValue() {
  28     return MACH_PORT_NULL;
  29   }
  30
  31   static void Free(mach_port_t port);
  32 };
  33
  34 }  // namespace internal
  35
  36 // A scoper for handling a Mach port that names a send right. Send rights are
  37 // reference counted, and this takes ownership of the right on construction
  38 // and then removes a reference to the right on destruction. If the reference
  39 // is the last one on the right, the right is deallocated.
  40 class BASE_EXPORT ScopedMachSendRight :
  41     public base::ScopedGeneric<mach_port_t, internal::SendRightTraits> {
  42  public:
  43   explicit ScopedMachSendRight(mach_port_t port = traits_type::InvalidValue())
  44       : ScopedGeneric(port) {}
  45
  46   operator mach_port_t() const { return get(); }
  47 };
  48
  49 // A scoper for handling a Mach port's receive right. There is only one
  50 // receive right per port. This takes ownership of the receive right on
  51 // construction and then destroys the right on destruction, turning all
  52 // outstanding send rights into dead names.
  53 class BASE_EXPORT ScopedMachReceiveRight :
  54     public base::ScopedGeneric<mach_port_t, internal::ReceiveRightTraits> {
  55  public:
  56   explicit ScopedMachReceiveRight(
  57       mach_port_t port = traits_type::InvalidValue()) : ScopedGeneric(port) {}
  58
  59   operator mach_port_t() const { return get(); }
  60 };
  61
  62 }  // namespace mac
  63 }  // namespace base
  64
  65 #endif  // BASE_MAC_SCOPED_MACH_PORT_H_