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   BASE_EXPORT 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   BASE_EXPORT static void Free(mach_port_t port);
  32 };
  33
  34 struct PortSetTraits {
  35   static mach_port_t InvalidValue() {
  36     return MACH_PORT_NULL;
  37   }
  38
  39   BASE_EXPORT static void Free(mach_port_t port);
  40 };
  41
  42 }  // namespace internal
  43
  44 // A scoper for handling a Mach port that names a send right. Send rights are
  45 // reference counted, and this takes ownership of the right on construction
  46 // and then removes a reference to the right on destruction. If the reference
  47 // is the last one on the right, the right is deallocated.
  48 class BASE_EXPORT ScopedMachSendRight :
  49     public base::ScopedGeneric<mach_port_t, internal::SendRightTraits> {
  50  public:
  51   explicit ScopedMachSendRight(mach_port_t port = traits_type::InvalidValue())
  52       : ScopedGeneric(port) {}
  53
  54   operator mach_port_t() const { return get(); }
  55 };
  56
  57 // A scoper for handling a Mach port's receive right. There is only one
  58 // receive right per port. This takes ownership of the receive right on
  59 // construction and then destroys the right on destruction, turning all
  60 // outstanding send rights into dead names.
  61 class BASE_EXPORT ScopedMachReceiveRight :
  62     public base::ScopedGeneric<mach_port_t, internal::ReceiveRightTraits> {
  63  public:
  64   explicit ScopedMachReceiveRight(
  65       mach_port_t port = traits_type::InvalidValue()) : ScopedGeneric(port) {}
  66
  67   operator mach_port_t() const { return get(); }
  68 };
  69
  70 // A scoper for handling a Mach port set. A port set can have only one
  71 // reference. This takes ownership of that single reference on construction and
  72 // destroys the port set on destruction. Destroying a port set does not destroy
  73 // the receive rights that are members of the port set.
  74 class BASE_EXPORT ScopedMachPortSet :
  75     public ScopedGeneric<mach_port_t, internal::PortSetTraits> {
  76  public:
  77   explicit ScopedMachPortSet(mach_port_t port = traits_type::InvalidValue())
  78       : ScopedGeneric(port) {}
  79
  80   operator mach_port_t() const { return get(); }
  81 };
  82
  83 }  // namespace mac
  84 }  // namespace base
  85
  86 #endif  // BASE_MAC_SCOPED_MACH_PORT_H_