| // 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 MEDIA_BASE_UNALIGNED_SHARED_MEMORY_H_ |
| #define MEDIA_BASE_UNALIGNED_SHARED_MEMORY_H_ |
| |
| #include <stdint.h> |
| |
| #include "base/macros.h" |
| #include "base/memory/shared_memory.h" |
| #include "media/base/media_export.h" |
| |
| namespace media { |
| |
| // Wrapper over base::SharedMemory that can be mapped at unaligned offsets. |
| class MEDIA_EXPORT UnalignedSharedMemory { |
| public: |
| UnalignedSharedMemory(const base::SharedMemoryHandle& handle, bool read_only); |
| ~UnalignedSharedMemory(); |
| |
| bool MapAt(off_t offset, size_t size); |
| void* memory() const; |
| |
| private: |
| base::SharedMemory shm_; |
| |
| // Offset withing |shm_| memory that data has been mapped; strictly less than |
| // base::SysInfo::VMAllocationGranularity(). |
| size_t misalignment_; |
| |
| DISALLOW_COPY_AND_ASSIGN(UnalignedSharedMemory); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_BASE_UNALIGNED_SHARED_MEMORY_H_ |