| // Copyright 2018 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef MOJO_CORE_PLATFORM_SHARED_MEMORY_MAPPING_H_ |
| #define MOJO_CORE_PLATFORM_SHARED_MEMORY_MAPPING_H_ |
| |
| #include <stddef.h> |
| |
| #include <memory> |
| |
| #include "base/logging.h" |
| #include "base/macros.h" |
| #include "base/memory/platform_shared_memory_region.h" |
| #include "base/memory/shared_memory_mapping.h" |
| #include "mojo/core/system_impl_export.h" |
| |
| namespace mojo { |
| namespace core { |
| |
| // A mapping of a |base::subtle::PlatformSharedMemoryRegion|, created |
| // exclusively by |SharedBufferDispatcher::MapBuffer()|. Automatically maps |
| // upon construction and unmaps upon destruction. |
| // |
| // Mappings are NOT thread-safe. |
| // |
| // This may represent either a |base::ReadOnlySharedMemoryMapping| OR a |
| // |base::WritableSharedMemoryMapping|, and it supports non-page-aligned base |
| // offsets for convenience. |
| class MOJO_SYSTEM_IMPL_EXPORT PlatformSharedMemoryMapping { |
| public: |
| enum class Type { |
| kReadOnly, |
| kWritable, |
| }; |
| |
| PlatformSharedMemoryMapping(base::subtle::PlatformSharedMemoryRegion* region, |
| size_t offset, |
| size_t length); |
| ~PlatformSharedMemoryMapping(); |
| |
| bool IsValid() const; |
| |
| void* GetBase() const; |
| size_t GetLength() const; |
| |
| private: |
| const Type type_; |
| const size_t offset_; |
| const size_t length_; |
| void* base_ = nullptr; |
| std::unique_ptr<base::SharedMemoryMapping> mapping_; |
| |
| DISALLOW_COPY_AND_ASSIGN(PlatformSharedMemoryMapping); |
| }; |
| |
| } // namespace core |
| } // namespace mojo |
| |
| #endif // MOJO_CORE_PLATFORM_SHARED_MEMORY_MAPPING_H_ |