1 /*
2 * Copyright (C) 2006 The Android Open Source Project
3 *
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
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
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.
15 */
16
17 //
18 // Shared file mapping class.
19 //
20
21 #define LOG_TAG "filemap"
22
23 #include <utils/FileMap.h>
24 #include <utils/Log.h>
25
26 #if defined(__MINGW32__) && !defined(__USE_MINGW_ANSI_STDIO)
27 # define PRId32 "I32d"
28 # define PRIx32 "I32x"
29 # define PRId64 "I64d"
30 #else
31 #include <inttypes.h>
32 #endif
33 #include <stdio.h>
34 #include <stdlib.h>
35
36 #if !defined(__MINGW32__)
37 #include <sys/mman.h>
38 #endif
39
40 #include <string.h>
41 #include <memory.h>
42 #include <errno.h>
43 #include <assert.h>
44
45 using namespace android;
46
47 /*static*/ long FileMap::mPageSize = -1;
48
49 // Constructor. Create an empty object.
FileMap(void)50 FileMap::FileMap(void)
51 : mFileName(NULL), mBasePtr(NULL), mBaseLength(0),
52 mDataPtr(NULL), mDataLength(0)
53 {
54 }
55
56 // Move Constructor.
FileMap(FileMap && other)57 FileMap::FileMap(FileMap&& other)
58 : mFileName(other.mFileName), mBasePtr(other.mBasePtr), mBaseLength(other.mBaseLength),
59 mDataOffset(other.mDataOffset), mDataPtr(other.mDataPtr), mDataLength(other.mDataLength)
60 #if defined(__MINGW32__)
61 , mFileHandle(other.mFileHandle), mFileMapping(other.mFileMapping)
62 #endif
63 {
64 other.mFileName = NULL;
65 other.mBasePtr = NULL;
66 other.mDataPtr = NULL;
67 #if defined(__MINGW32__)
68 other.mFileHandle = 0;
69 other.mFileMapping = 0;
70 #endif
71 }
72
73 // Move assign operator.
operator =(FileMap && other)74 FileMap& FileMap::operator=(FileMap&& other) {
75 mFileName = other.mFileName;
76 mBasePtr = other.mBasePtr;
77 mBaseLength = other.mBaseLength;
78 mDataOffset = other.mDataOffset;
79 mDataPtr = other.mDataPtr;
80 mDataLength = other.mDataLength;
81 other.mFileName = NULL;
82 other.mBasePtr = NULL;
83 other.mDataPtr = NULL;
84 #if defined(__MINGW32__)
85 mFileHandle = other.mFileHandle;
86 mFileMapping = other.mFileMapping;
87 other.mFileHandle = 0;
88 other.mFileMapping = 0;
89 #endif
90 return *this;
91 }
92
93 // Destructor.
~FileMap(void)94 FileMap::~FileMap(void)
95 {
96 if (mFileName != NULL) {
97 free(mFileName);
98 }
99 #if defined(__MINGW32__)
100 if (mBasePtr && UnmapViewOfFile(mBasePtr) == 0) {
101 ALOGD("UnmapViewOfFile(%p) failed, error = %" PRId32 "\n", mBasePtr,
102 GetLastError() );
103 }
104 if (mFileMapping != INVALID_HANDLE_VALUE) {
105 CloseHandle(mFileMapping);
106 }
107 #else
108 if (mBasePtr && munmap(mBasePtr, mBaseLength) != 0) {
109 ALOGD("munmap(%p, %zu) failed\n", mBasePtr, mBaseLength);
110 }
111 #endif
112 }
113
114
115 // Create a new mapping on an open file.
116 //
117 // Closing the file descriptor does not unmap the pages, so we don't
118 // claim ownership of the fd.
119 //
120 // Returns "false" on failure.
create(const char * origFileName,int fd,off64_t offset,size_t length,bool readOnly)121 bool FileMap::create(const char* origFileName, int fd, off64_t offset, size_t length,
122 bool readOnly)
123 {
124 #if defined(__MINGW32__)
125 int adjust;
126 off64_t adjOffset;
127 size_t adjLength;
128
129 if (mPageSize == -1) {
130 SYSTEM_INFO si;
131
132 GetSystemInfo( &si );
133 mPageSize = si.dwAllocationGranularity;
134 }
135
136 DWORD protect = readOnly ? PAGE_READONLY : PAGE_READWRITE;
137
138 mFileHandle = (HANDLE) _get_osfhandle(fd);
139 mFileMapping = CreateFileMapping( mFileHandle, NULL, protect, 0, 0, NULL);
140 if (mFileMapping == NULL) {
141 ALOGE("CreateFileMapping(%p, %" PRIx32 ") failed with error %" PRId32 "\n",
142 mFileHandle, protect, GetLastError() );
143 return false;
144 }
145
146 adjust = offset % mPageSize;
147 adjOffset = offset - adjust;
148 adjLength = length + adjust;
149
150 mBasePtr = MapViewOfFile( mFileMapping,
151 readOnly ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS,
152 0,
153 (DWORD)(adjOffset),
154 adjLength );
155 if (mBasePtr == NULL) {
156 ALOGE("MapViewOfFile(%" PRId64 ", %zu) failed with error %" PRId32 "\n",
157 adjOffset, adjLength, GetLastError() );
158 CloseHandle(mFileMapping);
159 mFileMapping = INVALID_HANDLE_VALUE;
160 return false;
161 }
162 #else // !defined(__MINGW32__)
163 int prot, flags, adjust;
164 off64_t adjOffset;
165 size_t adjLength;
166
167 void* ptr;
168
169 assert(fd >= 0);
170 assert(offset >= 0);
171 assert(length > 0);
172
173 // init on first use
174 if (mPageSize == -1) {
175 mPageSize = sysconf(_SC_PAGESIZE);
176 if (mPageSize == -1) {
177 ALOGE("could not get _SC_PAGESIZE\n");
178 return false;
179 }
180 }
181
182 adjust = offset % mPageSize;
183 adjOffset = offset - adjust;
184 adjLength = length + adjust;
185
186 flags = MAP_SHARED;
187 prot = PROT_READ;
188 if (!readOnly)
189 prot |= PROT_WRITE;
190
191 ptr = mmap(NULL, adjLength, prot, flags, fd, adjOffset);
192 if (ptr == MAP_FAILED) {
193 ALOGE("mmap(%lld,%zu) failed: %s\n",
194 (long long)adjOffset, adjLength, strerror(errno));
195 return false;
196 }
197 mBasePtr = ptr;
198 #endif // !defined(__MINGW32__)
199
200 mFileName = origFileName != NULL ? strdup(origFileName) : NULL;
201 mBaseLength = adjLength;
202 mDataOffset = offset;
203 mDataPtr = (char*) mBasePtr + adjust;
204 mDataLength = length;
205
206 assert(mBasePtr != NULL);
207
208 ALOGV("MAP: base %p/%zu data %p/%zu\n",
209 mBasePtr, mBaseLength, mDataPtr, mDataLength);
210
211 return true;
212 }
213
214 // Provide guidance to the system.
215 #if !defined(_WIN32)
advise(MapAdvice advice)216 int FileMap::advise(MapAdvice advice)
217 {
218 int cc, sysAdvice;
219
220 switch (advice) {
221 case NORMAL: sysAdvice = MADV_NORMAL; break;
222 case RANDOM: sysAdvice = MADV_RANDOM; break;
223 case SEQUENTIAL: sysAdvice = MADV_SEQUENTIAL; break;
224 case WILLNEED: sysAdvice = MADV_WILLNEED; break;
225 case DONTNEED: sysAdvice = MADV_DONTNEED; break;
226 default:
227 assert(false);
228 return -1;
229 }
230
231 cc = madvise(mBasePtr, mBaseLength, sysAdvice);
232 if (cc != 0)
233 ALOGW("madvise(%d) failed: %s\n", sysAdvice, strerror(errno));
234 return cc;
235 }
236
237 #else
advise(MapAdvice)238 int FileMap::advise(MapAdvice /* advice */)
239 {
240 return -1;
241 }
242 #endif
243