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28
29#ifndef XNU_LIBKERN_LIBKERN_CXX_OS_SHARED_PTR_H
30#define XNU_LIBKERN_LIBKERN_CXX_OS_SHARED_PTR_H
31
32#include <libkern/c++/intrusive_shared_ptr.h>
33#include <libkern/c++/OSMetaClass.h>
34
35struct intrusive_osobject_retainer {
36 static void
37 retain(OSMetaClassBase const& obj)
38 {
39 obj.retain();
40 }
41 static void
42 release(OSMetaClassBase const& obj)
43 {
44 obj.release();
45 }
46};
47
48template <typename Tag>
49struct intrusive_tagged_osobject_retainer {
50 static void
51 retain(OSMetaClassBase const& obj)
52 {
53 obj.taggedRetain(OSTypeID(Tag));
54 }
55 static void
56 release(OSMetaClassBase const& obj)
57 {
58 obj.taggedRelease(OSTypeID(Tag));
59 }
60};
61
62inline constexpr auto OSNoRetain = libkern::no_retain;
63inline constexpr auto OSRetain = libkern::retain;
64
65template <typename T>
66class __attribute__((trivial_abi)) OSSharedPtr: public libkern::intrusive_shared_ptr<T, intrusive_osobject_retainer> {
67 using libkern::intrusive_shared_ptr<T, intrusive_osobject_retainer>::intrusive_shared_ptr;
68};
69
70template <typename T, typename Tag>
71class __attribute__((trivial_abi)) OSTaggedSharedPtr: public libkern::intrusive_shared_ptr<T, intrusive_tagged_osobject_retainer<Tag> > {
72 using libkern::intrusive_shared_ptr<T, intrusive_tagged_osobject_retainer<Tag> >::intrusive_shared_ptr;
73};
74
75template <typename T>
76OSSharedPtr<T>
77OSMakeShared()
78{
79 T* memory = OSTypeAlloc(T);
80 // OSTypeAlloc returns an object with a refcount of 1, so we must not
81 // retain when constructing the shared pointer.
82 return OSSharedPtr<T>(memory, OSNoRetain);
83}
84
85template <typename Destination, typename Source>
86OSSharedPtr<Destination>
87OSDynamicPtrCast(OSSharedPtr<Source> const& source)
88{
89 Destination* raw = OSDynamicCast(Destination, source.get());
90 if (raw == nullptr) {
91 return nullptr;
92 } else {
93 OSSharedPtr<Destination> dest(raw, OSRetain);
94 return dest;
95 }
96}
97
98template <typename Destination, typename Source>
99OSSharedPtr<Destination>
100OSDynamicPtrCast(OSSharedPtr<Source> && source)
101{
102 Destination* raw = OSDynamicCast(Destination, source.get());
103 if (raw == nullptr) {
104 return nullptr;
105 } else {
106 OSSharedPtr<Destination> dest(raw, OSNoRetain);
107 source.detach(); // we stole the retain!
108 return dest;
109 }
110}
111
112template <typename Destination, typename Tag, typename Source>
113OSTaggedSharedPtr<Destination, Tag>
114OSDynamicPtrCast(OSTaggedSharedPtr<Source, Tag> const& source)
115{
116 Destination* raw = OSDynamicCast(Destination, source.get());
117 if (raw == nullptr) {
118 return nullptr;
119 } else {
120 OSTaggedSharedPtr<Destination, Tag> dest(raw, OSRetain);
121 return dest;
122 }
123}
124
125template <typename To, typename From>
126OSSharedPtr<To>
127OSStaticPtrCast(OSSharedPtr<From> const& ptr) noexcept
128{
129 return OSSharedPtr<To>(static_cast<To*>(ptr.get()), OSRetain);
130}
131
132template <typename To, typename From>
133OSSharedPtr<To>
134OSStaticPtrCast(OSSharedPtr<From>&& ptr) noexcept
135{
136 return OSSharedPtr<To>(static_cast<To*>(ptr.detach()), OSNoRetain);
137}
138
139template <typename To, typename From>
140OSSharedPtr<To>
141OSConstPtrCast(OSSharedPtr<From> const& ptr) noexcept
142{
143 return OSSharedPtr<To>(const_cast<To*>(ptr.get()), OSRetain);
144}
145
146template <typename To, typename From>
147OSSharedPtr<To>
148OSConstPtrCast(OSSharedPtr<From>&& ptr) noexcept
149{
150 return OSSharedPtr<To>(const_cast<To*>(ptr.detach()), OSNoRetain);
151}
152
153#endif // !XNU_LIBKERN_LIBKERN_CXX_OS_SHARED_PTR_H
154