audio_device_thread.h revision 9ab5563a3196760eb381d102cbb2bc0f7abc6a50
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" 119ab5563a3196760eb381d102cbb2bc0f7abc6a50Ben Murdoch#include "base/memory/shared_memory.h" 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/sync_socket.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/synchronization/lock.h" 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "media/audio/audio_parameters.h" 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "media/audio/shared_memory_util.h" 169ab5563a3196760eb381d102cbb2bc0f7abc6a50Ben Murdoch#include "media/base/media_export.h" 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 18c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)namespace base { 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class MessageLoop; 20c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles)} 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace media { 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class AudioBus; 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Data transfer between browser and render process uses a combination 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// of sync sockets and shared memory. To read from the socket and render 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// data, we use a worker thread, a.k.a. the AudioDeviceThread, which reads 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// data from the browser via the socket and fills the shared memory from the 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// audio thread via the AudioDeviceThread::Callback interface/class. 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// For more details see the documentation in audio_device.h. 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// TODO(tommi): Multiple audio input/output device instances should be able to 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// share the same thread instead of spinning one per instance. 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)class MEDIA_EXPORT AudioDeviceThread { 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This is the callback interface/base class that Audio[Output|Input]Device 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // implements to render input/output data. The callbacks run on the 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // thread owned by AudioDeviceThread. 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) class Callback { 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) public: 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) Callback(const AudioParameters& audio_parameters, 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::SharedMemoryHandle memory, 432a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) int memory_length, 442a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) int total_segments); 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual ~Callback(); 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // One time initialization for the callback object on the audio thread. 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void InitializeOnAudioThread(); 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Derived implementations must call shared_memory_.Map appropriately 515821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // before Process can be called. 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void MapSharedMemory() = 0; 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Called whenever we receive notifications about pending data. 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) virtual void Process(int pending_data) = 0; 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) protected: 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Protected so that derived classes can access directly. 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The variables are 'const' since values are calculated/set in the 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // constructor and must never change. 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const AudioParameters audio_parameters_; 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const int samples_per_ms_; 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const int bytes_per_ms_; 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::SharedMemory shared_memory_; 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const int memory_length_; 672a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) const int total_segments_; 682a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles) int segment_length_; 695821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 705821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 715821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(Callback); 725821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) }; 735821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 745821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AudioDeviceThread(); 755821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) ~AudioDeviceThread(); 765821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 775821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Starts the audio thread. The thread must not already be running. 785821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) void Start(AudioDeviceThread::Callback* callback, 795821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::SyncSocket::Handle socket, 805821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) const char* thread_name); 815821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 825821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // This tells the audio thread to stop and clean up the data. 835821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The method can stop the thread synchronously or asynchronously. 845821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // In the latter case, the thread will still be running after Stop() 855821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // returns, but the callback pointer is cleared so no further callbacks will 865821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // be made (IOW after Stop() returns, it is safe to delete the callback). 875821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The |loop_for_join| parameter is required for asynchronous operation 885821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // in order to join the worker thread and close the thread handle later via a 895821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // posted task. 905821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // If set to NULL, function will wait for the thread to exit before returning. 91c2e0dbddbe15c98d52c4786dac06cb8952a8ae6dTorne (Richard Coles) void Stop(base::MessageLoop* loop_for_join); 925821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 935821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Returns true if the thread is stopped or stopping. 945821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) bool IsStopped(); 955821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 965821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) private: 975821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // Our own private SimpleThread override. We implement this in a 985821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // private class so that we get the following benefits: 995821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 1) AudioDeviceThread doesn't expose SimpleThread methods. 1005821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // I.e. the caller can't call Start()/Stop() - which would be bad. 1015821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // 2) We override ThreadMain to add additional on-thread initialization 1025821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // while still synchronized with SimpleThread::Start() to provide 1035821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // reliable initialization. 1045821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) class Thread; 1055821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1065821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::Lock thread_lock_; 1075821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) scoped_refptr<AudioDeviceThread::Thread> thread_; 1085821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1095821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DISALLOW_COPY_AND_ASSIGN(AudioDeviceThread); 1105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)}; 1115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace media. 1135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 1145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#endif // MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_ 115