xref: /aosp_15_r20/external/perfetto/src/tracing/ipc/shared_memory_windows.h (revision 6dbdd20afdafa5e3ca9b8809fa73465d530080dc)
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 #ifndef SRC_TRACING_IPC_SHARED_MEMORY_WINDOWS_H_
18 #define SRC_TRACING_IPC_SHARED_MEMORY_WINDOWS_H_
19 
20 #include "perfetto/base/build_config.h"
21 
22 #if PERFETTO_BUILDFLAG(PERFETTO_OS_WIN)
23 
24 #include <string>
25 
26 #include "perfetto/base/build_config.h"
27 #include "perfetto/ext/base/scoped_file.h"
28 #include "perfetto/ext/tracing/core/shared_memory.h"
29 
30 namespace perfetto {
31 
32 // Implements the SharedMemory and its factory for the Windows IPC transport.
33 // This used only for standalone builds and NOT in chromium, which instead uses
34 // a custom Mojo wrapper (MojoSharedMemory in chromium's //services/tracing/).
35 class SharedMemoryWindows : public SharedMemory {
36  public:
37   class Factory : public SharedMemory::Factory {
38    public:
39     ~Factory() override;
40     std::unique_ptr<SharedMemory> CreateSharedMemory(size_t) override;
41   };
42 
43   // Create a brand new SHM region.
44   enum Flags { kNone = 0, kInheritableHandles };
45   static std::unique_ptr<SharedMemoryWindows> Create(
46       size_t size, Flags flags=Flags::kNone);
47   static std::unique_ptr<SharedMemoryWindows> Attach(const std::string& key);
48   static std::unique_ptr<SharedMemoryWindows> AttachToHandleWithKey(
49       base::ScopedPlatformHandle fd, const std::string& key);
50   ~SharedMemoryWindows() override;
key()51   const std::string& key() const { return key_; }
handle()52   const base::ScopedPlatformHandle& handle() const { return handle_; }
53 
54   // SharedMemory implementation.
55   using SharedMemory::start;  // Equal priority to const and non-const versions
start()56   const void* start() const override { return start_; }
size()57   size_t size() const override { return size_; }
58 
59  private:
60   SharedMemoryWindows(void* start,
61                       size_t size,
62                       std::string,
63                       base::ScopedPlatformHandle);
64   SharedMemoryWindows(const SharedMemoryWindows&) = delete;
65   SharedMemoryWindows& operator=(const SharedMemoryWindows&) = delete;
66 
67   void* const start_;
68   const size_t size_;
69   std::string key_;
70   base::ScopedPlatformHandle handle_;
71 };
72 
73 }  // namespace perfetto
74 
75 #endif  // OS_WIN
76 
77 #endif  // SRC_TRACING_IPC_SHARED_MEMORY_WINDOWS_H_
78