2 // Copyright (c) 2012 Samsung Electronics Co., Ltd.
4 // Licensed under the Apache License, Version 2.0 (the License);
5 // you may not use this file except in compliance with the License.
6 // You may obtain a copy of the License at
8 // http://www.apache.org/licenses/LICENSE-2.0
10 // Unless required by applicable law or agreed to in writing, software
11 // distributed under the License is distributed on an "AS IS" BASIS,
12 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 // See the License for the specific language governing permissions and
14 // limitations under the License.
18 * @file FIoMemoryMappedFile.h
19 * @brief This is the header file for the %MemoryMappedFile class.
21 * This header file contains the declarations of the %MemoryMappedFile class.
24 #ifndef _FIO_MEMORY_MAPPED_FILE_H_
25 #define _FIO_MEMORY_MAPPED_FILE_H_
27 #include <FOspConfig.h>
28 #include <FBaseObject.h>
30 namespace Tizen { namespace Io
34 * @enum MemoryMappedFileFlag
36 * Defines flags providing information about the handling of a memory mapped file.
40 enum MemoryMappedFileFlag
42 MEMORY_MAPPED_FILE_FLAG_SHARED = 0x01, /**< Changes are shared with other processes mapping the same file */
43 MEMORY_MAPPED_FILE_FLAG_PRIVATE = 0x02, /**< Changes are not visible to other processes mapping the same file */
44 MEMORY_MAPPED_FILE_FLAG_FIXED = 0x10 /**< This forces the system to use the specified mapping address exactly,
45 which should be a multiple of the page size */
49 * @enum MemoryMappedFileSyncFlag
51 * Defines synchronization flags of a memory mapped file.
55 enum MemoryMappedFileSyncFlag
57 MEMORY_MAPPED_FILE_SYNC_FLAG_ASYNC = 0x01, /**< Asynchronous update */
58 MEMORY_MAPPED_FILE_SYNC_FLAG_SYNC = 0x02 /**< Synchronous update */
62 * @class MemoryMappedFile
63 * @brief This class provides features mapping a file to virtual address space.
67 * @final This class is not intended for extension.
69 * The %MemoryMappedFile class provides features for using a memory mapped file,
70 * which maps the data of a file to an application's virtual address space.
78 * using namespace Tizen::Base;
79 * using namespace Tizen::Base::Collection;
80 * using namespace Tizen::Io;
81 * using namespace Tizen::App;
84 * MyApp::Execute(void)
86 * String filePath(App::GetInstance()->GetAppDataPath() + L”myFile.txt”);
87 * file.Construct(filePath, “w+);
89 * String testMsg(L”MemoryMappedFileTest”);
90 * file.Write(testMsg);
93 * long long mapLength = 4096;
94 * MemoryMappedFile mapFile;
95 * mapFile.Construct(file);
96 * void* pMappedAddr = mapFile.Map(null, mapLength, MEMORY_PROTECTION_MODE_READ | MEMORY_PROTECTION_MODE_WRITE, MEMORY_MAPPED_FILE_FLAG_SHARED, 0);
98 * char* pBuffer = new char[testMsg.GetLength() + 1];
99 * memcpy(pBuffer, pMappedAddr, testMsg.GetLength());
105 class _OSP_EXPORT_ MemoryMappedFile
106 : public Tizen::Base::Object
111 * The object is not fully constructed after this constructor is called. For full construction, the Construct() method must be called right after calling this constructor.
115 MemoryMappedFile(void);
118 * This destructor overrides Tizen::Base::Object::~Object().
122 ~MemoryMappedFile(void);
125 * Initializes this instance of %MemoryMappedFile with a specified file.
129 * @return An error code
130 * @param[in] file The File instance for memory mapping
131 * @exception E_SUCCESS The method is successful.
132 * @exception E_INVALID_ARG The specified @c file is not opened for reading. @n
133 * The opening mode should not be "w" or "a".
134 * @remarks The specified @c file should be initialized by the Io::File::Construct() method.
135 * @see Tizen::Io::File
137 result Construct(const File& file);
140 * Creates a new mapping for the specified file in the virtual address space of the calling process.
144 * @return The mapped address space, @n
145 * else @c null pointer if this method fails
146 * @param[in] address A starting address of the mapping @n
147 * If the specified @c address is @c null, the system chooses the address.
148 * It should be a multiple of the page size.
149 * @param[in] length The length of the mapping space
150 * @param[in] protection The memory protection of the mapping @n
151 * It is either Base::Runtime::MEMORY_PROTECTION_MODE_NONE or the bitwise-inclusive OR of one
152 * or more of the other modes in Base::Runtime::MemoryProtectionMode.
153 * @param[in] flag The flag providing information about the handling of a memory mapped file @n
154 * It is the bitwise-inclusive OR of the flags in Tizen::Io::MemoryMappedFileFlag.
155 * @param[in] offset The start offset of the specified file @n
156 * It should be a multiple of the page size.
157 * @exception E_SUCCESS The method is successful.
158 * @exception E_ILLEGAL_ACCESS The specified @c flag is MEMORY_MAPPED_FILE_FLAG_SHARED and the specified @c
159 * protection is MEMORY_PROTECTION_MODE_WRITE, but the specified file of
160 * MemoryMappedFile::Construct() is not opened with read-write mode.
161 * @exception E_INVALID_ARG Either of the following conditions has occurred: @n
162 * - The specified @c address or @c offset is not aligned on a page boundary. @n
163 * - The specified @c length is not positive. @n
164 * - The specified @c protection, @c flag, or @c offset @ is invalid. @n
165 * - The specified @c flag cannot contain both MEMORY_MAPPED_FILE_FLAG_PRIVATE and
166 * MEMORY_MAPPED_FILE_FLAG_SHARED.
167 * @exception E_MAX_EXCEEDED The number of mapped regions has exceeded the maximum limit.
168 * @exception E_OBJECT_LOCKED The mapped file has been locked.
169 * @exception E_OUT_OF_MEMORY Either of the following conditions has occurred: @n
170 * - The memory is insufficient. @n
171 * - The specified @c flag is MEMORY_MAPPED_FILE_FLAG_FIXED, and the specified address
172 * range exceeds that allowed for the address space of a current process.
173 * @exception E_IO Either of the following conditions has occurred: @n
174 * - The underlying file system does not support memory mapping. @n
175 * - The specified @c protection is MEMORY_PROTECTION_MODE_EXEC, but the mapped file
176 * exists on a file system that has been mounted no-exec.
177 * @remarks The specific error code can be accessed using the GetLastResult() method. @n
178 * When this instance is destructed, all mappings are deleted automatically.
179 * @see Tizen::Base::Runtime::MemoryManager
181 void* Map(void* address, long long length, unsigned long protection, unsigned long flag, long long offset);
184 * Deletes the mapping of the specified address space. @n
185 * Further references to the addresses within the range result in generation of an invalid memory access. @n
186 * This method flushes all changes of a shared mapping to the correlated file on the permanent storage.
190 * @return An error code
191 * @param[in] address The memory mapping address to unmap
192 * @param[in] length The length of the mapping space
193 * @exception E_SUCCESS The method is successful.
194 * @exception E_INVALID_ARG Either of the following conditions has occurred: @n
195 * - The specified @c address is not aligned on a page boundary. @n
196 * - The specified @c length is not positive. @n
197 * - The specified address range is out of the valid address space of a current process.
198 * @remarks When this instance is destructed, all mappings of the instance are not unmapped automatically.
200 result Unmap(void* address, long long length);
203 * Flushes all changes of an address range to the correlated file on the permanent storage.
207 * @return An error code
208 * @param[in] address The memory mapping address to synchronize
209 * @param[in] length The length of the mapping space
210 * @param[in] syncFlag The synchronization option
211 * @exception E_SUCCESS The method is successful.
212 * @exception E_INVALID_ARG Either of the following conditions has occurred: @n
213 * - The specified @c address is not aligned on a page boundary. @n
214 * - The specified @c length is not positive. @n
215 * - The specified @c syncFlag is invalid. @n
216 * - The specified @c address space is not mapped.
217 * @exception E_IO Either of the following conditions has occurred: @n
218 * - An unexpected device failure has occurred as the media ejected suddenly. @n
219 * - %File corruption is detected.
220 * @remarks The specific page size of a current file system is provided by Tizen::System::SystemInfo class with
222 * @see Tizen::Io::MemoryMappedFileSyncFlag
223 * @see Tizen::System::SystemInfo
225 result Sync(void* address, long long length, MemoryMappedFileSyncFlag syncFlag);
229 * The implementation of this copy constructor is intentionally blank and declared as private to prohibit copying of objects.
233 MemoryMappedFile(const MemoryMappedFile& rhs);
236 * The implementation of this copy assignment operator is intentionally blank and declared as private to prohibit copying of objects.
240 MemoryMappedFile& operator =(const MemoryMappedFile& rhs);
242 class _MemoryMappedFileImpl* __pMemoryMappedFileImpl;
244 friend class _MemoryMappedFileImpl;
246 }; // MemoryMappedFile
250 #endif // _FIO_MEMORY_MAPPED_FILE_H_