1 // Copyright (c) 2015 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "base/sys_info.h"
6 #include "shared_memory_region.h"
7
8 namespace media {
9
SharedMemoryRegion(const base::SharedMemoryHandle & handle,off_t offset,size_t size,bool read_only)10 SharedMemoryRegion::SharedMemoryRegion(const base::SharedMemoryHandle& handle,
11 off_t offset,
12 size_t size,
13 bool read_only)
14 : shm_(handle, read_only),
15 offset_(offset),
16 size_(size),
17 alignment_size_(offset % base::SysInfo::VMAllocationGranularity()) {
18 DCHECK_GE(offset_, 0) << "Invalid offset: " << offset_;
19 }
20
SharedMemoryRegion(const BitstreamBuffer & bitstream_buffer,bool read_only)21 SharedMemoryRegion::SharedMemoryRegion(const BitstreamBuffer& bitstream_buffer,
22 bool read_only)
23 : SharedMemoryRegion(bitstream_buffer.handle(),
24 bitstream_buffer.offset(),
25 bitstream_buffer.size(),
26 read_only) {}
27
Map()28 bool SharedMemoryRegion::Map() {
29 if (offset_ < 0) {
30 DVLOG(1) << "Invalid offset: " << offset_;
31 return false;
32 }
33 return shm_.MapAt(offset_ - alignment_size_, size_ + alignment_size_);
34 }
35
memory()36 void* SharedMemoryRegion::memory() {
37 int8_t* addr = reinterpret_cast<int8_t*>(shm_.memory());
38 return addr ? addr + alignment_size_ : nullptr;
39 }
40
41 } // namespace media
42