1 | // |
2 | // SharedMemoryImpl.h |
3 | // |
4 | // Library: Foundation |
5 | // Package: Processes |
6 | // Module: SharedMemoryImpl |
7 | // |
8 | // Definition of the SharedMemoryImpl class. |
9 | // |
10 | // Copyright (c) 2007, Applied Informatics Software Engineering GmbH. |
11 | // and Contributors. |
12 | // |
13 | // SPDX-License-Identifier: BSL-1.0 |
14 | // |
15 | |
16 | |
17 | #ifndef Foundation_SharedMemoryImpl_INCLUDED |
18 | #define Foundation_SharedMemoryImpl_INCLUDED |
19 | |
20 | |
21 | #include "Poco/Foundation.h" |
22 | #include "Poco/SharedMemory.h" |
23 | #include "Poco/RefCountedObject.h" |
24 | |
25 | |
26 | namespace Poco { |
27 | |
28 | |
29 | class Foundation_API SharedMemoryImpl: public RefCountedObject |
30 | /// Shared memory implementation for POSIX platforms. |
31 | { |
32 | public: |
33 | SharedMemoryImpl(const std::string& name, std::size_t size, SharedMemory::AccessMode mode, const void* addrHint, bool server); |
34 | /// Creates or connects to a shared memory object with the given name. |
35 | /// |
36 | /// For maximum portability, name should be a valid Unix filename and not |
37 | /// contain any slashes or backslashes. |
38 | /// |
39 | /// An address hint can be passed to the system, specifying the desired |
40 | /// start address of the shared memory area. Whether the hint |
41 | /// is actually honored is, however, up to the system. Windows platform |
42 | /// will generally ignore the hint. |
43 | /// |
44 | /// If server is set to false, the shared memory region will be unlinked |
45 | /// by calling shm_unlink when the SharedMemory object is destroyed. |
46 | |
47 | SharedMemoryImpl(const Poco::File& file, SharedMemory::AccessMode mode, const void* addrHint); |
48 | /// Maps the entire contents of file into a shared memory segment. |
49 | /// |
50 | /// An address hint can be passed to the system, specifying the desired |
51 | /// start address of the shared memory area. Whether the hint |
52 | /// is actually honored is, however, up to the system. Windows platform |
53 | /// will generally ignore the hint. |
54 | |
55 | char* begin() const; |
56 | /// Returns the start address of the shared memory segment. |
57 | |
58 | char* end() const; |
59 | /// Returns the one-past-end end address of the shared memory segment. |
60 | |
61 | protected: |
62 | void map(const void* addrHint); |
63 | /// Maps the shared memory object. |
64 | |
65 | void unmap(); |
66 | /// Unmaps the shared memory object. |
67 | |
68 | void close(); |
69 | /// Releases the handle for the shared memory segment. |
70 | |
71 | ~SharedMemoryImpl(); |
72 | /// Destroys the SharedMemoryImpl. |
73 | |
74 | private: |
75 | SharedMemoryImpl(); |
76 | SharedMemoryImpl(const SharedMemoryImpl&); |
77 | SharedMemoryImpl& operator = (const SharedMemoryImpl&); |
78 | |
79 | std::size_t _size; |
80 | int _fd; |
81 | char* _address; |
82 | SharedMemory::AccessMode _access; |
83 | std::string _name; |
84 | bool _fileMapped; |
85 | bool _server; |
86 | }; |
87 | |
88 | |
89 | // |
90 | // inlines |
91 | // |
92 | inline char* SharedMemoryImpl::begin() const |
93 | { |
94 | return _address; |
95 | } |
96 | |
97 | |
98 | inline char* SharedMemoryImpl::end() const |
99 | { |
100 | return _address + _size; |
101 | } |
102 | |
103 | |
104 | } // namespace Poco |
105 | |
106 | |
107 | #endif // Foundation_SharedMemoryImpl_INCLUDED |
108 | |