| OLD | NEW |
|---|
| (Empty) |
| 1 // Copyright 2013 The Chromium Authors. All rights reserved. | |
| 2 // Use of this source code is governed by a BSD-style license that can be | |
| 3 // found in the LICENSE file. | |
| 4 | |
| 5 #include "base/files/memory_mapped_file.h" | |
| 6 | |
| 7 #include <sys/mman.h> | |
| 8 #include <sys/stat.h> | |
| 9 #include <unistd.h> | |
| 10 | |
| 11 #include "base/logging.h" | |
| 12 #include "base/threading/thread_restrictions.h" | |
| 13 | |
| 14 namespace base { | |
| 15 | |
| 16 MemoryMappedFile::MemoryMappedFile() : data_(NULL), length_(0) { | |
| 17 } | |
| 18 | |
| 19 #if !defined(OS_NACL) | |
| 20 bool MemoryMappedFile::MapFileRegionToMemory( | |
| 21 const MemoryMappedFile::Region& region) { | |
| 22 ThreadRestrictions::AssertIOAllowed(); | |
| 23 | |
| 24 off_t map_start = 0; | |
| 25 size_t map_size = 0; | |
| 26 int32 data_offset = 0; | |
| 27 | |
| 28 if (region == MemoryMappedFile::Region::kWholeFile) { | |
| 29 int64 file_len = file_.GetLength(); | |
| 30 if (file_len == -1) { | |
| 31 DPLOG(ERROR) << "fstat " << file_.GetPlatformFile(); | |
| 32 return false; | |
| 33 } | |
| 34 map_size = static_cast<size_t>(file_len); | |
| 35 length_ = map_size; | |
| 36 } else { | |
| 37 // The region can be arbitrarily aligned. mmap, instead, requires both the | |
| 38 // start and size to be page-aligned. Hence, we map here the page-aligned | |
| 39 // outer region [|aligned_start|, |aligned_start| + |size|] which contains | |
| 40 // |region| and then add up the |data_offset| displacement. | |
| 41 int64 aligned_start = 0; | |
| 42 int64 aligned_size = 0; | |
| 43 CalculateVMAlignedBoundaries(region.offset, | |
| 44 region.size, | |
| 45 &aligned_start, | |
| 46 &aligned_size, | |
| 47 &data_offset); | |
| 48 | |
| 49 // Ensure that the casts in the mmap call below are sane. | |
| 50 if (aligned_start < 0 || aligned_size < 0 || | |
| 51 aligned_start > std::numeric_limits<off_t>::max() || | |
| 52 static_cast<uint64>(aligned_size) > | |
| 53 std::numeric_limits<size_t>::max() || | |
| 54 static_cast<uint64>(region.size) > std::numeric_limits<size_t>::max()) { | |
| 55 DLOG(ERROR) << "Region bounds are not valid for mmap"; | |
| 56 return false; | |
| 57 } | |
| 58 | |
| 59 map_start = static_cast<off_t>(aligned_start); | |
| 60 map_size = static_cast<size_t>(aligned_size); | |
| 61 length_ = static_cast<size_t>(region.size); | |
| 62 } | |
| 63 | |
| 64 data_ = static_cast<uint8*>(mmap(NULL, | |
| 65 map_size, | |
| 66 PROT_READ, | |
| 67 MAP_SHARED, | |
| 68 file_.GetPlatformFile(), | |
| 69 map_start)); | |
| 70 if (data_ == MAP_FAILED) { | |
| 71 DPLOG(ERROR) << "mmap " << file_.GetPlatformFile(); | |
| 72 return false; | |
| 73 } | |
| 74 | |
| 75 data_ += data_offset; | |
| 76 return true; | |
| 77 } | |
| 78 #endif | |
| 79 | |
| 80 void MemoryMappedFile::CloseHandles() { | |
| 81 ThreadRestrictions::AssertIOAllowed(); | |
| 82 | |
| 83 if (data_ != NULL) | |
| 84 munmap(data_, length_); | |
| 85 file_.Close(); | |
| 86 | |
| 87 data_ = NULL; | |
| 88 length_ = 0; | |
| 89 } | |
| 90 | |
| 91 } // namespace base | |
| OLD | NEW |
|---|
Chromium Code Reviews
