The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 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 | #include <stdio.h> |
| 27 | #include <stdlib.h> |
| 28 | |
| 29 | #ifdef HAVE_POSIX_FILEMAP |
| 30 | #include <sys/mman.h> |
| 31 | #endif |
| 32 | |
| 33 | #include <string.h> |
| 34 | #include <memory.h> |
| 35 | #include <errno.h> |
| 36 | #include <assert.h> |
| 37 | |
| 38 | using namespace android; |
| 39 | |
| 40 | /*static*/ long FileMap::mPageSize = -1; |
| 41 | |
| 42 | |
| 43 | /* |
| 44 | * Constructor. Create an empty object. |
| 45 | */ |
| 46 | FileMap::FileMap(void) |
| 47 | : mRefCount(1), mFileName(NULL), mBasePtr(NULL), mBaseLength(0), |
| 48 | mDataPtr(NULL), mDataLength(0) |
| 49 | { |
| 50 | } |
| 51 | |
| 52 | /* |
| 53 | * Destructor. |
| 54 | */ |
| 55 | FileMap::~FileMap(void) |
| 56 | { |
| 57 | assert(mRefCount == 0); |
| 58 | |
| 59 | //printf("+++ removing FileMap %p %u\n", mDataPtr, mDataLength); |
| 60 | |
| 61 | mRefCount = -100; // help catch double-free |
| 62 | if (mFileName != NULL) { |
| 63 | free(mFileName); |
| 64 | } |
| 65 | #ifdef HAVE_POSIX_FILEMAP |
Jeff Brown | db36064 | 2010-12-02 13:50:46 -0800 | [diff] [blame] | 66 | if (mBasePtr && munmap(mBasePtr, mBaseLength) != 0) { |
The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 67 | LOGD("munmap(%p, %d) failed\n", mBasePtr, (int) mBaseLength); |
| 68 | } |
| 69 | #endif |
| 70 | #ifdef HAVE_WIN32_FILEMAP |
Jeff Brown | db36064 | 2010-12-02 13:50:46 -0800 | [diff] [blame] | 71 | if (mBasePtr && UnmapViewOfFile(mBasePtr) == 0) { |
The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 72 | LOGD("UnmapViewOfFile(%p) failed, error = %ld\n", mBasePtr, |
| 73 | GetLastError() ); |
| 74 | } |
Jeff Brown | db36064 | 2010-12-02 13:50:46 -0800 | [diff] [blame] | 75 | if (mFileMapping != INVALID_HANDLE_VALUE) { |
| 76 | CloseHandle(mFileMapping); |
| 77 | } |
The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 78 | CloseHandle(mFileHandle); |
| 79 | #endif |
| 80 | } |
| 81 | |
| 82 | |
| 83 | /* |
| 84 | * Create a new mapping on an open file. |
| 85 | * |
| 86 | * Closing the file descriptor does not unmap the pages, so we don't |
| 87 | * claim ownership of the fd. |
| 88 | * |
| 89 | * Returns "false" on failure. |
| 90 | */ |
Kenny Root | 18092dd | 2010-11-24 12:56:06 -0800 | [diff] [blame] | 91 | bool FileMap::create(const char* origFileName, int fd, off64_t offset, size_t length, |
| 92 | bool readOnly) |
The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 93 | { |
| 94 | #ifdef HAVE_WIN32_FILEMAP |
| 95 | int adjust; |
Kenny Root | 18092dd | 2010-11-24 12:56:06 -0800 | [diff] [blame] | 96 | off64_t adjOffset; |
The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 97 | size_t adjLength; |
| 98 | |
| 99 | if (mPageSize == -1) { |
| 100 | SYSTEM_INFO si; |
| 101 | |
| 102 | GetSystemInfo( &si ); |
| 103 | mPageSize = si.dwAllocationGranularity; |
| 104 | } |
| 105 | |
| 106 | DWORD protect = readOnly ? PAGE_READONLY : PAGE_READWRITE; |
| 107 | |
| 108 | mFileHandle = (HANDLE) _get_osfhandle(fd); |
| 109 | mFileMapping = CreateFileMapping( mFileHandle, NULL, protect, 0, 0, NULL); |
| 110 | if (mFileMapping == NULL) { |
| 111 | LOGE("CreateFileMapping(%p, %lx) failed with error %ld\n", |
| 112 | mFileHandle, protect, GetLastError() ); |
| 113 | return false; |
| 114 | } |
| 115 | |
| 116 | adjust = offset % mPageSize; |
| 117 | adjOffset = offset - adjust; |
| 118 | adjLength = length + adjust; |
| 119 | |
| 120 | mBasePtr = MapViewOfFile( mFileMapping, |
| 121 | readOnly ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS, |
| 122 | 0, |
| 123 | (DWORD)(adjOffset), |
| 124 | adjLength ); |
| 125 | if (mBasePtr == NULL) { |
| 126 | LOGE("MapViewOfFile(%ld, %ld) failed with error %ld\n", |
| 127 | adjOffset, adjLength, GetLastError() ); |
| 128 | CloseHandle(mFileMapping); |
| 129 | mFileMapping = INVALID_HANDLE_VALUE; |
| 130 | return false; |
| 131 | } |
| 132 | #endif |
| 133 | #ifdef HAVE_POSIX_FILEMAP |
| 134 | int prot, flags, adjust; |
Kenny Root | 18092dd | 2010-11-24 12:56:06 -0800 | [diff] [blame] | 135 | off64_t adjOffset; |
The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 136 | size_t adjLength; |
| 137 | |
| 138 | void* ptr; |
| 139 | |
| 140 | assert(mRefCount == 1); |
| 141 | assert(fd >= 0); |
| 142 | assert(offset >= 0); |
| 143 | assert(length > 0); |
| 144 | |
| 145 | /* init on first use */ |
| 146 | if (mPageSize == -1) { |
| 147 | #if NOT_USING_KLIBC |
| 148 | mPageSize = sysconf(_SC_PAGESIZE); |
| 149 | if (mPageSize == -1) { |
| 150 | LOGE("could not get _SC_PAGESIZE\n"); |
| 151 | return false; |
| 152 | } |
| 153 | #else |
| 154 | /* this holds for Linux, Darwin, Cygwin, and doesn't pain the ARM */ |
| 155 | mPageSize = 4096; |
| 156 | #endif |
| 157 | } |
| 158 | |
| 159 | adjust = offset % mPageSize; |
| 160 | try_again: |
| 161 | adjOffset = offset - adjust; |
| 162 | adjLength = length + adjust; |
| 163 | |
| 164 | flags = MAP_SHARED; |
| 165 | prot = PROT_READ; |
| 166 | if (!readOnly) |
| 167 | prot |= PROT_WRITE; |
| 168 | |
| 169 | ptr = mmap(NULL, adjLength, prot, flags, fd, adjOffset); |
| 170 | if (ptr == MAP_FAILED) { |
| 171 | // Cygwin does not seem to like file mapping files from an offset. |
| 172 | // So if we fail, try again with offset zero |
| 173 | if (adjOffset > 0) { |
| 174 | adjust = offset; |
| 175 | goto try_again; |
| 176 | } |
| 177 | |
| 178 | LOGE("mmap(%ld,%ld) failed: %s\n", |
| 179 | (long) adjOffset, (long) adjLength, strerror(errno)); |
| 180 | return false; |
| 181 | } |
| 182 | mBasePtr = ptr; |
| 183 | #endif /* HAVE_POSIX_FILEMAP */ |
| 184 | |
| 185 | mFileName = origFileName != NULL ? strdup(origFileName) : NULL; |
| 186 | mBaseLength = adjLength; |
| 187 | mDataOffset = offset; |
| 188 | mDataPtr = (char*) mBasePtr + adjust; |
| 189 | mDataLength = length; |
| 190 | |
| 191 | assert(mBasePtr != NULL); |
| 192 | |
Steve Block | 6807e59 | 2011-10-20 11:56:00 +0100 | [diff] [blame^] | 193 | ALOGV("MAP: base %p/%d data %p/%d\n", |
The Android Open Source Project | edbf3b6 | 2009-03-03 19:31:44 -0800 | [diff] [blame] | 194 | mBasePtr, (int) mBaseLength, mDataPtr, (int) mDataLength); |
| 195 | |
| 196 | return true; |
| 197 | } |
| 198 | |
| 199 | /* |
| 200 | * Provide guidance to the system. |
| 201 | */ |
| 202 | int FileMap::advise(MapAdvice advice) |
| 203 | { |
| 204 | #if HAVE_MADVISE |
| 205 | int cc, sysAdvice; |
| 206 | |
| 207 | switch (advice) { |
| 208 | case NORMAL: sysAdvice = MADV_NORMAL; break; |
| 209 | case RANDOM: sysAdvice = MADV_RANDOM; break; |
| 210 | case SEQUENTIAL: sysAdvice = MADV_SEQUENTIAL; break; |
| 211 | case WILLNEED: sysAdvice = MADV_WILLNEED; break; |
| 212 | case DONTNEED: sysAdvice = MADV_DONTNEED; break; |
| 213 | default: |
| 214 | assert(false); |
| 215 | return -1; |
| 216 | } |
| 217 | |
| 218 | cc = madvise(mBasePtr, mBaseLength, sysAdvice); |
| 219 | if (cc != 0) |
| 220 | LOGW("madvise(%d) failed: %s\n", sysAdvice, strerror(errno)); |
| 221 | return cc; |
| 222 | #else |
| 223 | return -1; |
| 224 | #endif // HAVE_MADVISE |
| 225 | } |