| // Copyright (c) 2013 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 MEDIA_MIDI_MIDI_MANAGER_H_ |
| #define MEDIA_MIDI_MIDI_MANAGER_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <set> |
| #include <vector> |
| |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/synchronization/lock.h" |
| #include "base/thread_annotations.h" |
| #include "base/time/time.h" |
| #include "media/midi/midi_export.h" |
| #include "media/midi/midi_service.mojom.h" |
| |
| namespace base { |
| class SingleThreadTaskRunner; |
| } // namespace base |
| |
| namespace midi { |
| |
| class MidiService; |
| |
| // A MidiManagerClient registers with the MidiManager to receive MIDI data. |
| // See MidiManager::RequestAccess() and MidiManager::ReleaseAccess() |
| // for details. |
| // TODO(toyoshim): Consider to have a MidiServiceClient interface. |
| class MIDI_EXPORT MidiManagerClient { |
| public: |
| virtual ~MidiManagerClient() {} |
| |
| // AddInputPort() and AddOutputPort() are called before CompleteStartSession() |
| // is called to notify existing MIDI ports, and also called after that to |
| // notify new MIDI ports are added. |
| virtual void AddInputPort(const mojom::PortInfo& info) = 0; |
| virtual void AddOutputPort(const mojom::PortInfo& info) = 0; |
| |
| // SetInputPortState() and SetOutputPortState() are called to notify a known |
| // device gets disconnected, or connected again. |
| virtual void SetInputPortState(uint32_t port_index, |
| mojom::PortState state) = 0; |
| virtual void SetOutputPortState(uint32_t port_index, |
| mojom::PortState state) = 0; |
| |
| // CompleteStartSession() is called when platform dependent preparation is |
| // finished. |
| virtual void CompleteStartSession(mojom::Result result) = 0; |
| |
| // ReceiveMidiData() is called when MIDI data has been received from the |
| // MIDI system. |
| // |port_index| represents the specific input port from input_ports(). |
| // |data| represents a series of bytes encoding one or more MIDI messages. |
| // |length| is the number of bytes in |data|. |
| // |timestamp| is the time the data was received, in seconds. |
| virtual void ReceiveMidiData(uint32_t port_index, |
| const uint8_t* data, |
| size_t length, |
| base::TimeTicks timestamp) = 0; |
| |
| // AccumulateMidiBytesSent() is called to acknowledge when bytes have |
| // successfully been sent to the hardware. |
| // This happens as a result of the client having previously called |
| // MidiManager::DispatchSendMidiData(). |
| virtual void AccumulateMidiBytesSent(size_t n) = 0; |
| |
| // Detach() is called when MidiManager is going to shutdown immediately. |
| // Client should not touch MidiManager instance after Detach() is called. |
| virtual void Detach() = 0; |
| }; |
| |
| // Manages access to all MIDI hardware. MidiManager runs on the I/O thread. |
| // |
| // Note: We will eventually remove utility functions that are shared among |
| // platform dependent MidiManager inheritances such as MidiManagerClient |
| // management. MidiService should provide such shareable utility functions as |
| // it does TaskService. |
| class MIDI_EXPORT MidiManager { |
| public: |
| static const size_t kMaxPendingClientCount = 128; |
| |
| explicit MidiManager(MidiService* service); |
| virtual ~MidiManager(); |
| |
| static MidiManager* Create(MidiService* service); |
| |
| // A client calls StartSession() to receive and send MIDI data. |
| // If the session is ready to start, the MIDI system is lazily initialized |
| // and the client is registered to receive MIDI data. |
| // CompleteStartSession() is called with mojom::Result::OK if the session is |
| // started. Otherwise CompleteStartSession() is called with a proper |
| // mojom::Result code. |
| void StartSession(MidiManagerClient* client); |
| |
| // A client calls EndSession() to stop receiving MIDI data. |
| // Returns false if |client| did not start a session. |
| bool EndSession(MidiManagerClient* client); |
| |
| // Returns true if there is at least one client that keep a session open. |
| bool HasOpenSession(); |
| |
| // DispatchSendMidiData() is called when MIDI data should be sent to the MIDI |
| // system. |
| // This method is supposed to return immediately and should not block. |
| // |port_index| represents the specific output port from output_ports(). |
| // |data| represents a series of bytes encoding one or more MIDI messages. |
| // |length| is the number of bytes in |data|. |
| // |timestamp| is the time to send the data. A value of 0 means send "now" or |
| // as soon as possible. The default implementation is for unsupported |
| // platforms. |
| virtual void DispatchSendMidiData(MidiManagerClient* client, |
| uint32_t port_index, |
| const std::vector<uint8_t>& data, |
| base::TimeTicks timestamp); |
| |
| // This method ends all sessions by detaching and removing all registered |
| // clients. This method can be called from any thread. |
| void EndAllSessions(); |
| |
| protected: |
| friend class MidiManagerUsb; |
| |
| // Initializes the platform dependent MIDI system. MidiManager class has a |
| // default implementation that synchronously calls CompleteInitialization() |
| // with mojom::Result::NOT_SUPPORTED. A derived class for a specific platform |
| // should override this method correctly. |
| // Platform dependent initialization can be processed synchronously or |
| // asynchronously. When the initialization is completed, |
| // CompleteInitialization() should be called with |result|. |
| // |result| should be mojom::Result::OK on success, otherwise a proper |
| // mojom::Result. |
| virtual void StartInitialization(); |
| |
| // Called from a platform dependent implementation of StartInitialization(). |
| // The method distributes |result| to MIDIManagerClient objects in |
| // |pending_clients_|. |
| void CompleteInitialization(mojom::Result result); |
| |
| // The following five methods can be called on any thread to notify clients of |
| // status changes on ports, or to obtain port status. |
| void AddInputPort(const mojom::PortInfo& info); |
| void AddOutputPort(const mojom::PortInfo& info); |
| void SetInputPortState(uint32_t port_index, mojom::PortState state); |
| void SetOutputPortState(uint32_t port_index, mojom::PortState state); |
| mojom::PortState GetOutputPortState(uint32_t port_index); |
| |
| // Invoke AccumulateMidiBytesSent() for |client| safely. If the session was |
| // already closed, do nothing. Can be called on any thread. |
| void AccumulateMidiBytesSent(MidiManagerClient* client, size_t n); |
| |
| // Dispatches to all clients. Can be called on any thread. |
| void ReceiveMidiData(uint32_t port_index, |
| const uint8_t* data, |
| size_t length, |
| base::TimeTicks time); |
| |
| // Only for testing. |
| size_t GetClientCountForTesting(); |
| size_t GetPendingClientCountForTesting(); |
| |
| MidiService* service() { return service_; } |
| |
| private: |
| enum class InitializationState { |
| NOT_STARTED, |
| STARTED, |
| COMPLETED, |
| }; |
| |
| // Note: Members that are not protected by any lock should be accessed only on |
| // the I/O thread. |
| |
| // Tracks platform dependent initialization state. |
| InitializationState initialization_state_ = InitializationState::NOT_STARTED; |
| |
| // Keeps the platform dependent initialization result if initialization is |
| // completed. Otherwise keeps mojom::Result::NOT_INITIALIZED. |
| mojom::Result result_ = mojom::Result::NOT_INITIALIZED; |
| |
| // Keeps track of all clients who are waiting for CompleteStartSession(). |
| std::set<MidiManagerClient*> pending_clients_ GUARDED_BY(lock_); |
| |
| // Keeps track of all clients who wish to receive MIDI data. |
| std::set<MidiManagerClient*> clients_ GUARDED_BY(lock_); |
| |
| // Keeps a SingleThreadTaskRunner of the thread that calls StartSession in |
| // order to invoke CompleteStartSession() on the thread. This is touched only |
| // on the IO thread usually, but to be guarded by |lock_| for thread checks. |
| scoped_refptr<base::SingleThreadTaskRunner> session_thread_runner_ |
| GUARDED_BY(lock_); |
| |
| // Keeps all PortInfo. |
| std::vector<mojom::PortInfo> input_ports_ GUARDED_BY(lock_); |
| std::vector<mojom::PortInfo> output_ports_ GUARDED_BY(lock_); |
| |
| // Tracks if actual data transmission happens. |
| bool data_sent_ GUARDED_BY(lock_) = false; |
| bool data_received_ GUARDED_BY(lock_) = false; |
| |
| // Protects members above. |
| base::Lock lock_; |
| |
| // MidiService outlives MidiManager. |
| MidiService* const service_; |
| |
| DISALLOW_COPY_AND_ASSIGN(MidiManager); |
| }; |
| |
| } // namespace midi |
| |
| #endif // MEDIA_MIDI_MIDI_MANAGER_H_ |