1 /*
2 * Copyright (C) 2021 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 #include "src/tracing/ipc/shared_memory_windows.h"
18
19 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
20
21 #include <memory>
22 #include <random>
23
24 #include <Windows.h>
25
26 #include "perfetto/base/logging.h"
27 #include "perfetto/ext/base/string_utils.h"
28
29 namespace perfetto {
30
31 // static
Create(size_t size)32 std::unique_ptr<SharedMemoryWindows> SharedMemoryWindows::Create(size_t size) {
33 base::ScopedPlatformHandle shmem_handle;
34 std::random_device rnd_dev;
35 uint64_t rnd_key = (static_cast<uint64_t>(rnd_dev()) << 32) | rnd_dev();
36 std::string key = "perfetto_shm_" + base::Uint64ToHexStringNoPrefix(rnd_key);
37 shmem_handle.reset(CreateFileMappingA(
38 INVALID_HANDLE_VALUE, // Use paging file.
39 nullptr, // Default security.
40 PAGE_READWRITE,
41 static_cast<DWORD>(size >> 32), // maximum object size (high-order DWORD)
42 static_cast<DWORD>(size), // maximum object size (low-order DWORD)
43 key.c_str()));
44
45 if (!shmem_handle) {
46 PERFETTO_PLOG("CreateFileMapping() call failed");
47 return nullptr;
48 }
49 void* start =
50 MapViewOfFile(*shmem_handle, FILE_MAP_ALL_ACCESS, /*offsetHigh=*/0,
51 /*offsetLow=*/0, size);
52 if (!start) {
53 PERFETTO_PLOG("MapViewOfFile() failed");
54 return nullptr;
55 }
56
57 return std::unique_ptr<SharedMemoryWindows>(new SharedMemoryWindows(
58 start, size, std::move(key), std::move(shmem_handle)));
59 }
60
61 // static
Attach(const std::string & key)62 std::unique_ptr<SharedMemoryWindows> SharedMemoryWindows::Attach(
63 const std::string& key) {
64 base::ScopedPlatformHandle shmem_handle;
65 shmem_handle.reset(
66 OpenFileMappingA(FILE_MAP_ALL_ACCESS, /*inherit=*/false, key.c_str()));
67 if (!shmem_handle) {
68 PERFETTO_PLOG("Failed to OpenFileMapping()");
69 return nullptr;
70 }
71
72 void* start =
73 MapViewOfFile(*shmem_handle, FILE_MAP_ALL_ACCESS, /*offsetHigh=*/0,
74 /*offsetLow=*/0, /*dwNumberOfBytesToMap=*/0);
75 if (!start) {
76 PERFETTO_PLOG("MapViewOfFile() failed");
77 return nullptr;
78 }
79
80 MEMORY_BASIC_INFORMATION info{};
81 if (!VirtualQuery(start, &info, sizeof(info))) {
82 PERFETTO_PLOG("VirtualQuery() failed");
83 return nullptr;
84 }
85 size_t size = info.RegionSize;
86 return std::unique_ptr<SharedMemoryWindows>(
87 new SharedMemoryWindows(start, size, key, std::move(shmem_handle)));
88 }
89
SharedMemoryWindows(void * start,size_t size,std::string key,base::ScopedPlatformHandle handle)90 SharedMemoryWindows::SharedMemoryWindows(void* start,
91 size_t size,
92 std::string key,
93 base::ScopedPlatformHandle handle)
94 : start_(start),
95 size_(size),
96 key_(std::move(key)),
97 handle_(std::move(handle)) {}
98
~SharedMemoryWindows()99 SharedMemoryWindows::~SharedMemoryWindows() {
100 if (start_)
101 UnmapViewOfFile(start_);
102 }
103
104 SharedMemoryWindows::Factory::~Factory() = default;
105
CreateSharedMemory(size_t size)106 std::unique_ptr<SharedMemory> SharedMemoryWindows::Factory::CreateSharedMemory(
107 size_t size) {
108 return SharedMemoryWindows::Create(size);
109 }
110
111 } // namespace perfetto
112
113 #endif // !OS_WIN
114