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1 | ////////////////////////////////////////////////////////////////////////////// |
2 | // | |
3 | // (C) Copyright Ion Gaztanaga 2009-2012. Distributed under the Boost | |
4 | // Software License, Version 1.0. (See accompanying file | |
5 | // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) | |
6 | // | |
7 | // See http://www.boost.org/libs/interprocess for documentation. | |
8 | // | |
9 | ////////////////////////////////////////////////////////////////////////////// | |
10 | ||
11 | #ifndef BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP | |
12 | #define BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP | |
13 | ||
14 | #ifndef BOOST_CONFIG_HPP | |
15 | # include <boost/config.hpp> | |
16 | #endif | |
17 | # | |
18 | #if defined(BOOST_HAS_PRAGMA_ONCE) | |
19 | # pragma once | |
20 | #endif | |
21 | ||
22 | #include <boost/interprocess/detail/config_begin.hpp> | |
23 | #include <boost/interprocess/detail/workaround.hpp> | |
24 | ||
25 | #if !defined(BOOST_INTERPROCESS_XSI_SHARED_MEMORY_OBJECTS) | |
26 | #error "This header can't be used in operating systems without XSI (System V) shared memory support" | |
27 | #endif | |
28 | ||
29 | #include <boost/interprocess/creation_tags.hpp> | |
30 | #include <boost/interprocess/exceptions.hpp> | |
31 | #include <boost/interprocess/detail/utilities.hpp> | |
32 | ||
33 | #include <boost/interprocess/detail/os_file_functions.hpp> | |
34 | #include <boost/interprocess/interprocess_fwd.hpp> | |
35 | #include <boost/interprocess/exceptions.hpp> | |
36 | #include <boost/interprocess/xsi_key.hpp> | |
37 | #include <boost/interprocess/permissions.hpp> | |
38 | #include <boost/interprocess/detail/simple_swap.hpp> | |
39 | // move | |
40 | #include <boost/move/utility_core.hpp> | |
41 | // other boost | |
42 | #include <boost/cstdint.hpp> | |
43 | // std | |
44 | #include <cstddef> | |
45 | // OS | |
46 | #include <sys/shm.h> | |
47 | ||
48 | ||
49 | //!\file | |
50 | //!Describes a class representing a native xsi shared memory. | |
51 | ||
52 | namespace boost { | |
53 | namespace interprocess { | |
54 | ||
55 | //!A class that wraps XSI (System V) shared memory. | |
56 | //!Unlike shared_memory_object, xsi_shared_memory needs a valid | |
57 | //!xsi_key to identify a shared memory object. | |
58 | //! | |
59 | //!Warning: XSI shared memory and interprocess portable | |
60 | //!shared memory (boost::interprocess::shared_memory_object) | |
61 | //!can't communicate between them. | |
62 | class xsi_shared_memory | |
63 | { | |
64 | #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED) | |
65 | //Non-copyable and non-assignable | |
66 | BOOST_MOVABLE_BUT_NOT_COPYABLE(xsi_shared_memory) | |
67 | #endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED | |
68 | ||
69 | public: | |
70 | //!Default constructor. | |
71 | //!Represents an empty xsi_shared_memory. | |
72 | xsi_shared_memory(); | |
73 | ||
74 | //!Initializes *this with a shmid previously obtained (possibly from another process) | |
75 | //!This lower-level initializer allows shared memory mapping without having a key. | |
76 | xsi_shared_memory(open_only_t, int shmid) | |
77 | : m_shmid (shmid) | |
78 | {} | |
79 | ||
80 | //!Creates a new XSI shared memory from 'key', with size "size" and permissions "perm". | |
81 | //!If the shared memory previously exists, throws an error. | |
82 | xsi_shared_memory(create_only_t, const xsi_key &key, std::size_t size, const permissions& perm = permissions()) | |
83 | { this->priv_open_or_create(ipcdetail::DoCreate, key, perm, size); } | |
84 | ||
85 | //!Opens an existing shared memory with identifier 'key' or creates a new XSI shared memory from | |
86 | //!identifier 'key', with size "size" and permissions "perm". | |
87 | xsi_shared_memory(open_or_create_t, const xsi_key &key, std::size_t size, const permissions& perm = permissions()) | |
88 | { this->priv_open_or_create(ipcdetail::DoOpenOrCreate, key, perm, size); } | |
89 | ||
90 | //!Tries to open a XSI shared memory with identifier 'key' | |
91 | //!If the shared memory does not previously exist, it throws an error. | |
92 | xsi_shared_memory(open_only_t, const xsi_key &key) | |
93 | { this->priv_open_or_create(ipcdetail::DoOpen, key, permissions(), 0); } | |
94 | ||
95 | //!Moves the ownership of "moved"'s shared memory object to *this. | |
96 | //!After the call, "moved" does not represent any shared memory object. | |
97 | //!Does not throw | |
98 | xsi_shared_memory(BOOST_RV_REF(xsi_shared_memory) moved) | |
99 | : m_shmid(-1) | |
100 | { this->swap(moved); } | |
101 | ||
102 | //!Moves the ownership of "moved"'s shared memory to *this. | |
103 | //!After the call, "moved" does not represent any shared memory. | |
104 | //!Does not throw | |
105 | xsi_shared_memory &operator=(BOOST_RV_REF(xsi_shared_memory) moved) | |
106 | { | |
107 | xsi_shared_memory tmp(boost::move(moved)); | |
108 | this->swap(tmp); | |
109 | return *this; | |
110 | } | |
111 | ||
112 | //!Swaps two xsi_shared_memorys. Does not throw | |
113 | void swap(xsi_shared_memory &other); | |
114 | ||
115 | //!Destroys *this. The shared memory won't be destroyed, just | |
116 | //!this connection to it. Use remove() to destroy the shared memory. | |
117 | ~xsi_shared_memory(); | |
118 | ||
119 | //!Returns the shared memory ID that | |
120 | //!identifies the shared memory | |
121 | int get_shmid() const; | |
122 | ||
123 | //!Returns the mapping handle. | |
124 | //!Never throws | |
125 | mapping_handle_t get_mapping_handle() const; | |
126 | ||
127 | //!Erases the XSI shared memory object identified by shmid | |
128 | //!from the system. | |
129 | //!Returns false on error. Never throws | |
130 | static bool remove(int shmid); | |
131 | ||
132 | #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED) | |
133 | private: | |
134 | ||
135 | //!Closes a previously opened file mapping. Never throws. | |
136 | bool priv_open_or_create( ipcdetail::create_enum_t type | |
137 | , const xsi_key &key | |
138 | , const permissions& perm | |
139 | , std::size_t size); | |
140 | int m_shmid; | |
141 | #endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED | |
142 | }; | |
143 | ||
144 | #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED) | |
145 | ||
146 | inline xsi_shared_memory::xsi_shared_memory() | |
147 | : m_shmid(-1) | |
148 | {} | |
149 | ||
150 | inline xsi_shared_memory::~xsi_shared_memory() | |
151 | {} | |
152 | ||
153 | inline int xsi_shared_memory::get_shmid() const | |
154 | { return m_shmid; } | |
155 | ||
156 | inline void xsi_shared_memory::swap(xsi_shared_memory &other) | |
157 | { | |
158 | (simple_swap)(m_shmid, other.m_shmid); | |
159 | } | |
160 | ||
161 | inline mapping_handle_t xsi_shared_memory::get_mapping_handle() const | |
162 | { mapping_handle_t mhnd = { m_shmid, true}; return mhnd; } | |
163 | ||
164 | inline bool xsi_shared_memory::priv_open_or_create | |
165 | (ipcdetail::create_enum_t type, const xsi_key &key, const permissions& permissions, std::size_t size) | |
166 | { | |
167 | int perm = permissions.get_permissions(); | |
168 | perm &= 0x01FF; | |
169 | int shmflg = perm; | |
170 | ||
171 | switch(type){ | |
172 | case ipcdetail::DoOpen: | |
173 | shmflg |= 0; | |
174 | break; | |
175 | case ipcdetail::DoCreate: | |
176 | shmflg |= IPC_CREAT | IPC_EXCL; | |
177 | break; | |
178 | case ipcdetail::DoOpenOrCreate: | |
179 | shmflg |= IPC_CREAT; | |
180 | break; | |
181 | default: | |
182 | { | |
183 | error_info err = other_error; | |
184 | throw interprocess_exception(err); | |
185 | } | |
186 | } | |
187 | ||
188 | int ret = ::shmget(key.get_key(), size, shmflg); | |
189 | int shmid = ret; | |
190 | if((type == ipcdetail::DoOpen) && (-1 != ret)){ | |
191 | //Now get the size | |
192 | ::shmid_ds xsi_ds; | |
193 | ret = ::shmctl(ret, IPC_STAT, &xsi_ds); | |
194 | size = xsi_ds.shm_segsz; | |
195 | } | |
196 | if(-1 == ret){ | |
197 | error_info err = system_error_code(); | |
198 | throw interprocess_exception(err); | |
199 | } | |
200 | ||
201 | m_shmid = shmid; | |
202 | return true; | |
203 | } | |
204 | ||
205 | inline bool xsi_shared_memory::remove(int shmid) | |
206 | { return -1 != ::shmctl(shmid, IPC_RMID, 0); } | |
207 | ||
208 | #endif //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED | |
209 | ||
210 | } //namespace interprocess { | |
211 | } //namespace boost { | |
212 | ||
213 | #include <boost/interprocess/detail/config_end.hpp> | |
214 | ||
215 | #endif //BOOST_INTERPROCESS_XSI_SHARED_MEMORY_HPP |