audio_device_thread.h revision 5821806d5e7f356e8fa4b058a389a808ea183019
15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#ifndef MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/basictypes.h" 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/ref_counted.h" 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/memory/scoped_ptr.h" 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/shared_memory.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/sync_socket.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/synchronization/lock.h" 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "media/base/media_export.h" 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "media/audio/audio_parameters.h" 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "media/audio/shared_memory_util.h" 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class MessageLoop; 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace media { 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class AudioBus; 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Data transfer between browser and render process uses a combination 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// of sync sockets and shared memory. To read from the socket and render 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// data, we use a worker thread, a.k.a. the AudioDeviceThread, which reads 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// data from the browser via the socket and fills the shared memory from the 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// audio thread via the AudioDeviceThread::Callback interface/class. 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// For more details see the documentation in audio_device.h. 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// TODO(tommi): Multiple audio input/output device instances should be able to 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// share the same thread instead of spinning one per instance. 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class MEDIA_EXPORT AudioDeviceThread { 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This is the callback interface/base class that Audio[Output|Input]Device 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // implements to render input/output data. The callbacks run on the 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // thread owned by AudioDeviceThread. 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) class Callback { 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Callback(const AudioParameters& audio_parameters, 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int input_channels, 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::SharedMemoryHandle memory, 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int memory_length); 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~Callback(); 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // One time initialization for the callback object on the audio thread. 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void InitializeOnAudioThread(); 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Derived implementations must call shared_memory_.Map appropriately 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // before Process can be called. 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void MapSharedMemory() = 0; 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Called whenever we receive notifications about pending data. 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void Process(int pending_data) = 0; 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) protected: 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Protected so that derived classes can access directly. 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The variables are 'const' since values are calculated/set in the 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // constructor and must never change. 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const AudioParameters audio_parameters_; 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const int input_channels_; 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const int samples_per_ms_; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const int bytes_per_ms_; 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::SharedMemory shared_memory_; 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const int memory_length_; 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 675821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 685821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(Callback); 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AudioDeviceThread(); 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ~AudioDeviceThread(); 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Starts the audio thread. The thread must not already be running. 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void Start(AudioDeviceThread::Callback* callback, 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::SyncSocket::Handle socket, 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const char* thread_name); 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This tells the audio thread to stop and clean up the data. 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The method can stop the thread synchronously or asynchronously. 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // In the latter case, the thread will still be running after Stop() 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // returns, but the callback pointer is cleared so no further callbacks will 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // be made (IOW after Stop() returns, it is safe to delete the callback). 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The |loop_for_join| parameter is required for asynchronous operation 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // in order to join the worker thread and close the thread handle later via a 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // posted task. 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If set to NULL, function will wait for the thread to exit before returning. 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void Stop(MessageLoop* loop_for_join); 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Returns true if the thread is stopped or stopping. 915821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool IsStopped(); 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Our own private SimpleThread override. We implement this in a 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // private class so that we get the following benefits: 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 1) AudioDeviceThread doesn't expose SimpleThread methods. 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // I.e. the caller can't call Start()/Stop() - which would be bad. 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2) We override ThreadMain to add additional on-thread initialization 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // while still synchronized with SimpleThread::Start() to provide 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // reliable initialization. 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) class Thread; 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::Lock thread_lock_; 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) scoped_refptr<AudioDeviceThread::Thread> thread_; 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(AudioDeviceThread); 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace media. 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ 112