| // Copyright (c) 2012 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. |
| |
| #ifndef SERVICES_AUDIO_SYNC_READER_H_ |
| #define SERVICES_AUDIO_SYNC_READER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| #include <memory> |
| #include <string> |
| |
| #include "base/callback.h" |
| #include "base/compiler_specific.h" |
| #include "base/macros.h" |
| #include "base/memory/unsafe_shared_memory_region.h" |
| #include "base/process/process.h" |
| #include "base/sync_socket.h" |
| #include "base/time/time.h" |
| #include "build/build_config.h" |
| #include "media/base/audio_bus.h" |
| #include "services/audio/output_controller.h" |
| |
| #if defined(OS_POSIX) |
| #include "base/file_descriptor_posix.h" |
| #endif |
| |
| namespace audio { |
| |
| // An OutputController::SyncReader implementation using SyncSocket. This is used |
| // by OutputController to provide a low latency data source for transmitting |
| // audio packets between the Audio Service process and the process where the |
| // mojo client runs. |
| class SyncReader : public OutputController::SyncReader { |
| public: |
| // Constructor: Creates and maps shared memory; and initializes a SyncSocket |
| // pipe, assigning the client handle to |foreign_socket|. The caller must |
| // confirm IsValid() returns true before any other methods are called. |
| SyncReader(base::RepeatingCallback<void(const std::string&)> log_callback, |
| const media::AudioParameters& params, |
| base::CancelableSyncSocket* foreign_socket); |
| |
| ~SyncReader() override; |
| |
| // Returns true if the SyncReader initialized successfully, and |
| // TakeSharedMemoryRegion() will return a valid region. |
| bool IsValid() const; |
| |
| // Transfers shared memory region ownership to a caller. It shouldn't be |
| // called more than once. |
| base::UnsafeSharedMemoryRegion TakeSharedMemoryRegion(); |
| |
| // OutputController::SyncReader implementation. |
| void RequestMoreData(base::TimeDelta delay, |
| base::TimeTicks delay_timestamp, |
| int prior_frames_skipped) override; |
| void Read(media::AudioBus* dest) override; |
| void Close() override; |
| |
| private: |
| // Blocks until data is ready for reading or a timeout expires. Returns false |
| // if an error or timeout occurs. |
| bool WaitUntilDataIsReady(); |
| |
| const base::RepeatingCallback<void(const std::string&)> log_callback_; |
| |
| base::UnsafeSharedMemoryRegion shared_memory_region_; |
| base::WritableSharedMemoryMapping shared_memory_mapping_; |
| |
| // Mutes all incoming samples. This is used to prevent audible sound |
| // during automated testing. |
| const bool mute_audio_for_testing_; |
| |
| // Denotes that the most recent socket error has been logged. Used to avoid |
| // log spam. |
| bool had_socket_error_; |
| |
| // Socket for transmitting audio data. |
| base::CancelableSyncSocket socket_; |
| |
| const uint32_t output_bus_buffer_size_; |
| |
| // Shared memory wrapper used for transferring audio data to Read() callers. |
| std::unique_ptr<media::AudioBus> output_bus_; |
| |
| // Track the number of times the renderer missed its real-time deadline and |
| // report a UMA stat during destruction. |
| size_t renderer_callback_count_; |
| size_t renderer_missed_callback_count_; |
| size_t trailing_renderer_missed_callback_count_; |
| |
| // The maximum amount of time to wait for data from the renderer. Calculated |
| // from the parameters given at construction. |
| const base::TimeDelta maximum_wait_time_; |
| |
| // The index of the audio buffer we're expecting to be sent from the renderer; |
| // used to block with timeout for audio data. |
| uint32_t buffer_index_; |
| |
| DISALLOW_COPY_AND_ASSIGN(SyncReader); |
| }; |
| |
| } // namespace audio |
| |
| #endif // SERVICES_AUDIO_SYNC_READER_H_ |