base/android/scoped_hardware_buffer_handle.cc

   1 // Copyright 2018 The Chromium Authors
   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/android/scoped_hardware_buffer_handle.h"
   6
   7 #include "base/android/android_hardware_buffer_compat.h"
   8 #include "base/logging.h"
   9 #include "base/posix/unix_domain_socket.h"
  10
  11 namespace base {
  12 namespace android {
  13
  14 ScopedHardwareBufferHandle::ScopedHardwareBufferHandle() = default;
  15
  16 ScopedHardwareBufferHandle::ScopedHardwareBufferHandle(
  17     ScopedHardwareBufferHandle&& other) {
  18   *this = std::move(other);
  19 }
  20
  21 ScopedHardwareBufferHandle::~ScopedHardwareBufferHandle() {
  22   reset();
  23 }
  24
  25 // static
  26 ScopedHardwareBufferHandle ScopedHardwareBufferHandle::Adopt(
  27     AHardwareBuffer* buffer) {
  28   return ScopedHardwareBufferHandle(buffer);
  29 }
  30
  31 // static
  32 ScopedHardwareBufferHandle ScopedHardwareBufferHandle::Create(
  33     AHardwareBuffer* buffer) {
  34   AndroidHardwareBufferCompat::GetInstance().Acquire(buffer);
  35   return ScopedHardwareBufferHandle(buffer);
  36 }
  37
  38 ScopedHardwareBufferHandle& ScopedHardwareBufferHandle::operator=(
  39     ScopedHardwareBufferHandle&& other) {
  40   reset();
  41   std::swap(buffer_, other.buffer_);
  42   return *this;
  43 }
  44
  45 bool ScopedHardwareBufferHandle::is_valid() const {
  46   return buffer_ != nullptr;
  47 }
  48
  49 AHardwareBuffer* ScopedHardwareBufferHandle::get() const {
  50   return buffer_;
  51 }
  52
  53 void ScopedHardwareBufferHandle::reset() {
  54   if (buffer_) {
  55     AndroidHardwareBufferCompat::GetInstance().Release(buffer_);
  56     buffer_ = nullptr;
  57   }
  58 }
  59
  60 AHardwareBuffer* ScopedHardwareBufferHandle::Take() {
  61   AHardwareBuffer* buffer = buffer_;
  62   buffer_ = nullptr;
  63   return buffer;
  64 }
  65
  66 ScopedHardwareBufferHandle ScopedHardwareBufferHandle::Clone() const {
  67   DCHECK(buffer_);
  68   AndroidHardwareBufferCompat::GetInstance().Acquire(buffer_);
  69   return ScopedHardwareBufferHandle(buffer_);
  70 }
  71
  72 ScopedFD ScopedHardwareBufferHandle::SerializeAsFileDescriptor() const {
  73   DCHECK(is_valid());
  74
  75   ScopedFD reader, writer;
  76   if (!CreateSocketPair(&reader, &writer)) {
  77     PLOG(ERROR) << "socketpair";
  78     return ScopedFD();
  79   }
  80
  81   // NOTE: SendHandleToUnixSocket does NOT acquire or retain a reference to the
  82   // buffer object. The caller is therefore responsible for ensuring that the
  83   // buffer remains alive through the lifetime of this file descriptor.
  84   int result =
  85       AndroidHardwareBufferCompat::GetInstance().SendHandleToUnixSocket(
  86           buffer_, writer.get());
  87   if (result < 0) {
  88     PLOG(ERROR) << "send";
  89     return ScopedFD();
  90   }
  91
  92   return reader;
  93 }
  94
  95 // static
  96 ScopedHardwareBufferHandle
  97 ScopedHardwareBufferHandle::DeserializeFromFileDescriptor(ScopedFD fd) {
  98   DCHECK(fd.is_valid());
  99   DCHECK(AndroidHardwareBufferCompat::IsSupportAvailable());
 100   AHardwareBuffer* buffer = nullptr;
 101
 102   // NOTE: Upon success, RecvHandleFromUnixSocket acquires a new reference to
 103   // the AHardwareBuffer.
 104   int result =
 105       AndroidHardwareBufferCompat::GetInstance().RecvHandleFromUnixSocket(
 106           fd.get(), &buffer);
 107   if (result < 0) {
 108     PLOG(ERROR) << "recv";
 109     return ScopedHardwareBufferHandle();
 110   }
 111
 112   return ScopedHardwareBufferHandle(buffer);
 113 }
 114
 115 ScopedHardwareBufferHandle::ScopedHardwareBufferHandle(AHardwareBuffer* buffer)
 116     : buffer_(buffer) {
 117   DCHECK(AndroidHardwareBufferCompat::IsSupportAvailable());
 118 }
 119
 120 }  // namespace android
 121 }  // namespace base