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1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. | 1 // Copyright (c) 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/memory/discardable_memory_android.h" | 5 #include "base/memory/discardable_memory.h" |
6 | |
7 #include <sys/mman.h> | |
8 #include <unistd.h> | |
9 | |
10 #include <limits> | |
11 | 6 |
12 #include "base/android/sys_utils.h" | 7 #include "base/android/sys_utils.h" |
13 #include "base/basictypes.h" | 8 #include "base/basictypes.h" |
14 #include "base/compiler_specific.h" | 9 #include "base/compiler_specific.h" |
15 #include "base/file_util.h" | |
16 #include "base/lazy_instance.h" | 10 #include "base/lazy_instance.h" |
17 #include "base/logging.h" | 11 #include "base/logging.h" |
18 #include "base/memory/discardable_memory_allocator_android.h" | 12 #include "base/memory/discardable_memory_allocator_android.h" |
19 #include "base/memory/discardable_memory_emulated.h" | 13 #include "base/memory/discardable_memory_emulated.h" |
20 #include "base/memory/discardable_memory_malloc.h" | 14 #include "base/memory/discardable_memory_malloc.h" |
21 #include "third_party/ashmem/ashmem.h" | |
22 | 15 |
23 namespace base { | 16 namespace base { |
24 namespace { | 17 namespace { |
25 | 18 |
26 const char kAshmemAllocatorName[] = "DiscardableMemoryAllocator"; | 19 const char kAshmemAllocatorName[] = "DiscardableMemoryAllocator"; |
27 | 20 |
28 struct DiscardableMemoryAllocatorWrapper { | 21 struct DiscardableMemoryAllocatorWrapper { |
29 DiscardableMemoryAllocatorWrapper() | 22 DiscardableMemoryAllocatorWrapper() |
30 : allocator(kAshmemAllocatorName, | 23 : allocator(kAshmemAllocatorName, |
31 GetOptimalAshmemRegionSizeForAllocator()) { | 24 GetOptimalAshmemRegionSizeForAllocator()) { |
32 } | 25 } |
33 | 26 |
34 internal::DiscardableMemoryAllocator allocator; | 27 internal::DiscardableMemoryAllocator allocator; |
35 | 28 |
36 private: | 29 private: |
37 // Returns 64 MBytes for a 512 MBytes device, 128 MBytes for 1024 MBytes... | 30 // Returns 64 MBytes for a 512 MBytes device, 128 MBytes for 1024 MBytes... |
38 static size_t GetOptimalAshmemRegionSizeForAllocator() { | 31 static size_t GetOptimalAshmemRegionSizeForAllocator() { |
39 // Note that this may do some I/O (without hitting the disk though) so it | 32 // Note that this may do some I/O (without hitting the disk though) so it |
40 // should not be called on the critical path. | 33 // should not be called on the critical path. |
41 return base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8; | 34 return base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8; |
42 } | 35 } |
43 }; | 36 }; |
44 | 37 |
45 LazyInstance<DiscardableMemoryAllocatorWrapper>::Leaky g_context = | 38 LazyInstance<DiscardableMemoryAllocatorWrapper>::Leaky g_context = |
46 LAZY_INSTANCE_INITIALIZER; | 39 LAZY_INSTANCE_INITIALIZER; |
47 | 40 |
48 } // namespace | 41 } // namespace |
49 | 42 |
50 namespace internal { | |
51 | |
52 bool CreateAshmemRegion(const char* name, | |
53 size_t size, | |
54 int* out_fd, | |
55 void** out_address) { | |
56 int fd = ashmem_create_region(name, size); | |
57 if (fd < 0) { | |
58 DLOG(ERROR) << "ashmem_create_region() failed"; | |
59 return false; | |
60 } | |
61 file_util::ScopedFD fd_closer(&fd); | |
62 | |
63 const int err = ashmem_set_prot_region(fd, PROT_READ | PROT_WRITE); | |
64 if (err < 0) { | |
65 DLOG(ERROR) << "Error " << err << " when setting protection of ashmem"; | |
66 return false; | |
67 } | |
68 | |
69 // There is a problem using MAP_PRIVATE here. As we are constantly calling | |
70 // Lock() and Unlock(), data could get lost if they are not written to the | |
71 // underlying file when Unlock() gets called. | |
72 void* const address = mmap( | |
73 NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); | |
74 if (address == MAP_FAILED) { | |
75 DPLOG(ERROR) << "Failed to map memory."; | |
76 return false; | |
77 } | |
78 | |
79 ignore_result(fd_closer.release()); | |
80 *out_fd = fd; | |
81 *out_address = address; | |
82 return true; | |
83 } | |
84 | |
85 bool CloseAshmemRegion(int fd, size_t size, void* address) { | |
86 if (munmap(address, size) == -1) { | |
87 DPLOG(ERROR) << "Failed to unmap memory."; | |
88 close(fd); | |
89 return false; | |
90 } | |
91 return close(fd) == 0; | |
92 } | |
93 | |
94 DiscardableMemoryLockStatus LockAshmemRegion(int fd, | |
95 size_t off, | |
96 size_t size, | |
97 const void* address) { | |
98 const int result = ashmem_pin_region(fd, off, size); | |
99 DCHECK_EQ(0, mprotect(address, size, PROT_READ | PROT_WRITE)); | |
100 return result == ASHMEM_WAS_PURGED ? DISCARDABLE_MEMORY_LOCK_STATUS_PURGED | |
101 : DISCARDABLE_MEMORY_LOCK_STATUS_SUCCESS; | |
102 } | |
103 | |
104 bool UnlockAshmemRegion(int fd, size_t off, size_t size, const void* address) { | |
105 const int failed = ashmem_unpin_region(fd, off, size); | |
106 if (failed) | |
107 DLOG(ERROR) << "Failed to unpin memory."; | |
108 // This allows us to catch accesses to unlocked memory. | |
109 DCHECK_EQ(0, mprotect(address, size, PROT_NONE)); | |
110 return !failed; | |
111 } | |
112 | |
113 } // namespace internal | |
114 | |
115 // static | 43 // static |
116 void DiscardableMemory::RegisterMemoryPressureListeners() { | 44 void DiscardableMemory::RegisterMemoryPressureListeners() { |
117 internal::DiscardableMemoryEmulated::RegisterMemoryPressureListeners(); | 45 internal::DiscardableMemoryEmulated::RegisterMemoryPressureListeners(); |
118 } | 46 } |
119 | 47 |
120 // static | 48 // static |
121 void DiscardableMemory::UnregisterMemoryPressureListeners() { | 49 void DiscardableMemory::UnregisterMemoryPressureListeners() { |
122 internal::DiscardableMemoryEmulated::UnregisterMemoryPressureListeners(); | 50 internal::DiscardableMemoryEmulated::UnregisterMemoryPressureListeners(); |
123 } | 51 } |
124 | 52 |
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169 bool DiscardableMemory::PurgeForTestingSupported() { | 97 bool DiscardableMemory::PurgeForTestingSupported() { |
170 return false; | 98 return false; |
171 } | 99 } |
172 | 100 |
173 // static | 101 // static |
174 void DiscardableMemory::PurgeForTesting() { | 102 void DiscardableMemory::PurgeForTesting() { |
175 NOTIMPLEMENTED(); | 103 NOTIMPLEMENTED(); |
176 } | 104 } |
177 | 105 |
178 } // namespace base | 106 } // namespace base |
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