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 // Note: ported from Chromium commit head: 60f9667 5 6 #include "base/sys_info.h" 7 #include "shared_memory_region.h" 8 9 namespace media { 10 11 SharedMemoryRegion::SharedMemoryRegion(const base::SharedMemoryHandle& handle, 12 off_t offset, 13 size_t size, 14 bool read_only) 15 : shm_(handle, read_only), 16 offset_(offset), 17 size_(size), 18 alignment_size_(offset % base::SysInfo::VMAllocationGranularity()) { 19 DCHECK_GE(offset_, 0) << "Invalid offset: " << offset_; 20 } 21 22 SharedMemoryRegion::SharedMemoryRegion(const BitstreamBuffer& bitstream_buffer, 23 bool read_only) 24 : SharedMemoryRegion(bitstream_buffer.handle(), 25 bitstream_buffer.offset(), 26 bitstream_buffer.size(), 27 read_only) {} 28 29 bool SharedMemoryRegion::Map() { 30 if (offset_ < 0) { 31 DVLOG(1) << "Invalid offset: " << offset_; 32 return false; 33 } 34 return shm_.MapAt(offset_ - alignment_size_, size_ + alignment_size_); 35 } 36 37 void* SharedMemoryRegion::memory() { 38 int8_t* addr = reinterpret_cast<int8_t*>(shm_.memory()); 39 return addr ? addr + alignment_size_ : nullptr; 40 } 41 42 } // namespace media 43
