Initial audio implementation.

ppapi/shared_impl/audio_impl.cc

Index: ppapi/shared_impl/audio_impl.cc
===================================================================
--- ppapi/shared_impl/audio_impl.cc	(revision 0)
+++ ppapi/shared_impl/audio_impl.cc	(revision 0)
@@ -0,0 +1,96 @@
+// Copyright (c) 2010 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.
+
+#include "ppapi/shared_impl/audio_impl.h"
+
+#include "base/logging.h"
+
+namespace pp {
+namespace shared_impl {
+
+AudioImpl::AudioImpl()
+    : playing_(false),
+      shared_memory_size_(0),
+      callback_(NULL),
+      user_data_(NULL) {
+}
+
+AudioImpl::~AudioImpl() {
+  // Closing the socket causes the thread to exit - wait for it.
+  socket_->Close();
+  if (audio_thread_.get()) {
+    audio_thread_->Join();
+    audio_thread_.reset();
+  }
+}
+
+void AudioImpl::SetCallback(PPB_Audio_Callback callback, void* user_data) {
+  callback_ = callback;
+  user_data_ = user_data;
+}
+
+void AudioImpl::SetStartPlaybackState() {
+  DCHECK(!playing_);
+  DCHECK(!audio_thread_.get());
+
+  // If the socket doesn't exist, that means that the plugin has started before
+  // the browser has had a chance to create all the shared memory info and
+  // notify us. This is a common case. In this case, we just set the playing_
+  // flag and the playback will automatically start when that data is available
+  // in SetStreamInfo.
+  if (callback_ && socket_.get())
+    StartThread();
+  playing_ = true;
+}
+
+void AudioImpl::SetStopPlaybackState() {
+  DCHECK(playing_);
+
+  if (audio_thread_.get()) {
+    audio_thread_->Join();
+    audio_thread_.reset();
+  }
+  playing_ = false;
+}
+
+void AudioImpl::SetStreamInfo(base::SharedMemoryHandle shared_memory_handle,
+                              size_t shared_memory_size,
+                              base::SyncSocket::Handle socket_handle) {
+  socket_.reset(new base::SyncSocket(socket_handle));
+  shared_memory_.reset(new base::SharedMemory(shared_memory_handle, false));
+  shared_memory_size_ = shared_memory_size;
+
+  if (callback_) {
+    shared_memory_->Map(shared_memory_size_);
+
+    // In common case StartPlayback() was called before StreamCreated().
+    if (playing_)
+      StartThread();
+  }
+}
+
+void AudioImpl::StartThread() {
+  DCHECK(callback_);
+  DCHECK(!audio_thread_.get());
+  audio_thread_.reset(new base::DelegateSimpleThread(
+      this, "plugin_audio_thread"));
+  audio_thread_->Start();
+}
+
+void AudioImpl::Run() {
+  int pending_data;
+  void* buffer = shared_memory_->memory();
+
+  while (sizeof(pending_data) ==
+      socket_->Receive(&pending_data, sizeof(pending_data)) &&
+      pending_data >= 0) {
+    // Exit the thread on pause.
+    if (pending_data < 0)
+      return;
+    callback_(buffer, shared_memory_size_, user_data_);
+  }
+}
+
+}  // namespace shared_impl
+}  // namespace pp