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1 // Copyright 2013 The Chromium Authors. All rights reserved. | 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 | 2 // Use of this source code is governed by a BSD-style license that can be |
3 // found in the LICENSE file. | 3 // found in the LICENSE file. |
4 | 4 |
5 #include "base/files/memory_mapped_file.h" | 5 #include "base/files/memory_mapped_file.h" |
6 | 6 |
7 #include <stddef.h> | 7 #include <stddef.h> |
8 #include <stdint.h> | 8 #include <stdint.h> |
9 | 9 |
10 #include <limits> | 10 #include <limits> |
11 | 11 |
12 #include "base/files/file_path.h" | 12 #include "base/files/file_path.h" |
13 #include "base/strings/string16.h" | 13 #include "base/strings/string16.h" |
14 #include "base/threading/thread_restrictions.h" | 14 #include "base/threading/thread_restrictions.h" |
15 | 15 |
16 namespace base { | 16 namespace base { |
17 | 17 |
18 MemoryMappedFile::MemoryMappedFile() : data_(NULL), length_(0), image_(false) { | 18 MemoryMappedFile::MemoryMappedFile() : data_(NULL), length_(0), image_(false) { |
19 } | 19 } |
20 | 20 |
21 bool MemoryMappedFile::InitializeAsImageSection(const FilePath& file_name) { | 21 bool MemoryMappedFile::InitializeAsImageSection(const FilePath& file_name) { |
22 image_ = true; | 22 image_ = true; |
23 return Initialize(file_name); | 23 return Initialize(file_name); |
24 } | 24 } |
25 | 25 |
26 bool MemoryMappedFile::MapFileRegionToMemory( | 26 bool MemoryMappedFile::MapFileRegionToMemory( |
27 const MemoryMappedFile::Region& region) { | 27 const MemoryMappedFile::Region& region, |
28 Access access) { | |
28 ThreadRestrictions::AssertIOAllowed(); | 29 ThreadRestrictions::AssertIOAllowed(); |
29 | 30 |
30 if (!file_.IsValid()) | 31 if (!file_.IsValid()) |
31 return false; | 32 return false; |
32 | 33 |
33 int flags = image_ ? SEC_IMAGE | PAGE_READONLY : PAGE_READONLY; | 34 int flags = image_ ? SEC_IMAGE : 0; |
forshaw
2016/05/09 21:23:19
While we're changing this I'd highly recommend we
bcwhite
2016/05/10 00:44:41
Hmmm.... How about I work towards that in a diffe
forshaw
2016/05/10 07:04:30
Well we could do it in another CL, sure. I'd argue
bcwhite
2016/05/10 21:00:54
Since it's not actually in-use anywhere, I guess t
| |
35 uint32_t size_low = 0; | |
36 uint32_t size_high = 0; | |
37 switch (access) { | |
38 case READ_ONLY: | |
39 flags |= PAGE_READONLY; | |
40 break; | |
41 case READ_WRITE: | |
42 flags |= PAGE_READWRITE; | |
43 break; | |
44 case READ_WRITE_EXTEND: | |
45 flags |= PAGE_READWRITE; | |
46 size_high = static_cast<uint32_t>(region.size >> 32); | |
47 size_low = static_cast<uint32_t>(region.size & 0xFFFFFFFF); | |
48 break; | |
49 } | |
34 | 50 |
35 file_mapping_.Set(::CreateFileMapping(file_.GetPlatformFile(), NULL, | 51 file_mapping_.Set(::CreateFileMapping(file_.GetPlatformFile(), NULL, flags, |
36 flags, 0, 0, NULL)); | 52 size_high, size_low, NULL)); |
erikchen
2016/05/10 02:21:51
A question, mostly for forshaw:
Should we be remo
forshaw
2016/05/10 07:04:30
I don't believe so, at least as far as I can tell
| |
37 if (!file_mapping_.IsValid()) | 53 if (!file_mapping_.IsValid()) |
38 return false; | 54 return false; |
39 | 55 |
40 LARGE_INTEGER map_start = {}; | 56 LARGE_INTEGER map_start = {}; |
41 SIZE_T map_size = 0; | 57 SIZE_T map_size = 0; |
42 int32_t data_offset = 0; | 58 int32_t data_offset = 0; |
43 | 59 |
44 if (region == MemoryMappedFile::Region::kWholeFile) { | 60 if (region == MemoryMappedFile::Region::kWholeFile) { |
61 DCHECK_NE(READ_WRITE_EXTEND, access); | |
45 int64_t file_len = file_.GetLength(); | 62 int64_t file_len = file_.GetLength(); |
46 if (file_len <= 0 || file_len > std::numeric_limits<int32_t>::max()) | 63 if (file_len <= 0 || file_len > std::numeric_limits<int32_t>::max()) |
47 return false; | 64 return false; |
48 length_ = static_cast<size_t>(file_len); | 65 length_ = static_cast<size_t>(file_len); |
49 } else { | 66 } else { |
50 // The region can be arbitrarily aligned. MapViewOfFile, instead, requires | 67 // The region can be arbitrarily aligned. MapViewOfFile, instead, requires |
51 // that the start address is aligned to the VM granularity (which is | 68 // that the start address is aligned to the VM granularity (which is |
52 // typically larger than a page size, for instance 32k). | 69 // typically larger than a page size, for instance 32k). |
53 // Also, conversely to POSIX's mmap, the |map_size| doesn't have to be | 70 // Also, conversely to POSIX's mmap, the |map_size| doesn't have to be |
54 // aligned and must be less than or equal the mapped file size. | 71 // aligned and must be less than or equal the mapped file size. |
(...skipping 10 matching lines...) Expand all Loading... | |
65 static_cast<uint64_t>(size) > std::numeric_limits<SIZE_T>::max()) { | 82 static_cast<uint64_t>(size) > std::numeric_limits<SIZE_T>::max()) { |
66 DLOG(ERROR) << "Region bounds are not valid for MapViewOfFile"; | 83 DLOG(ERROR) << "Region bounds are not valid for MapViewOfFile"; |
67 return false; | 84 return false; |
68 } | 85 } |
69 map_start.QuadPart = aligned_start; | 86 map_start.QuadPart = aligned_start; |
70 map_size = static_cast<SIZE_T>(size); | 87 map_size = static_cast<SIZE_T>(size); |
71 length_ = static_cast<size_t>(region.size); | 88 length_ = static_cast<size_t>(region.size); |
72 } | 89 } |
73 | 90 |
74 data_ = static_cast<uint8_t*>( | 91 data_ = static_cast<uint8_t*>( |
75 ::MapViewOfFile(file_mapping_.Get(), FILE_MAP_READ, map_start.HighPart, | 92 ::MapViewOfFile(file_mapping_.Get(), |
76 map_start.LowPart, map_size)); | 93 (flags & PAGE_READONLY) ? FILE_MAP_READ : FILE_MAP_WRITE, |
94 map_start.HighPart, map_start.LowPart, map_size)); | |
77 if (data_ == NULL) | 95 if (data_ == NULL) |
78 return false; | 96 return false; |
79 data_ += data_offset; | 97 data_ += data_offset; |
80 return true; | 98 return true; |
81 } | 99 } |
82 | 100 |
83 void MemoryMappedFile::CloseHandles() { | 101 void MemoryMappedFile::CloseHandles() { |
84 if (data_) | 102 if (data_) |
85 ::UnmapViewOfFile(data_); | 103 ::UnmapViewOfFile(data_); |
86 if (file_mapping_.IsValid()) | 104 if (file_mapping_.IsValid()) |
87 file_mapping_.Close(); | 105 file_mapping_.Close(); |
88 if (file_.IsValid()) | 106 if (file_.IsValid()) |
89 file_.Close(); | 107 file_.Close(); |
90 | 108 |
91 data_ = NULL; | 109 data_ = NULL; |
92 length_ = 0; | 110 length_ = 0; |
93 } | 111 } |
94 | 112 |
95 } // namespace base | 113 } // namespace base |
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