Manage MIDI related objects and sessions' lifecycles correctly

media/midi/midi_manager.h

 // 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 <map>
 #include <set>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
 #include "media/base/media_export.h"
 #include "media/midi/midi_port_info.h"
 #include "media/midi/midi_result.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }  // namespace base
 
 namespace media {
 
 // A MidiManagerClient registers with the MidiManager to receive MIDI data.
 // See MidiManager::RequestAccess() and MidiManager::ReleaseAccess()
 // for details.
 class MEDIA_EXPORT MidiManagerClient {
  public:
   virtual ~MidiManagerClient() {}
 
   // CompleteStartSession() is called when platform dependent preparation is
   // finished.
-  virtual void CompleteStartSession(int client_id, MidiResult result) = 0;
+  virtual void CompleteStartSession(MidiResult 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 port_index,
                                const uint8* data,
                                size_t length,
@@ skipping 18 matching lines @@
   // thread.
   static MidiManager* Create();
 
   // 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 MIDI_OK if the session is started.
   // Otherwise CompleteStartSession() is called with proper MidiResult code.
   // StartSession() and EndSession() can be called on the Chrome_IOThread.
   // CompleteStartSession() will be invoked on the same Chrome_IOThread.
-  void StartSession(MidiManagerClient* client, int client_id);
+  void StartSession(MidiManagerClient* client);
 
   // A client calls EndSession() to stop receiving MIDI data.
   void EndSession(MidiManagerClient* client);
 
   // 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|.
@@ skipping 56 matching lines @@
 
   size_t clients_size_for_testing() const { return clients_.size(); }
   size_t pending_clients_size_for_testing() const {
     return pending_clients_.size();
   }
 
  private:
   void CompleteInitializationInternal(MidiResult result);
 
   // Keeps track of all clients who wish to receive MIDI data.
-  typedef std::set<MidiManagerClient*> ClientList;
-  ClientList clients_;
+  typedef std::set<MidiManagerClient*> ClientSet;
+  ClientSet clients_;
 
   // Keeps track of all clients who are waiting for CompleteStartSession().
-  typedef std::multimap<MidiManagerClient*, int> PendingClientMap;
-  PendingClientMap pending_clients_;
+  ClientSet pending_clients_;
 
   // Keeps a SingleThreadTaskRunner of the thread that calls StartSession in
   // order to invoke CompleteStartSession() on the thread.
   scoped_refptr<base::SingleThreadTaskRunner> session_thread_runner_;
 
   // Keeps true if platform dependent initialization is already completed.
   bool initialized_;
 
   // Keeps the platform dependent initialization result if initialization is
   // completed. Otherwise keeps MIDI_NOT_SUPPORTED.
   MidiResult result_;
 
   // Protects access to |clients_|, |pending_clients_|, |initialized_|, and
   // |result_|.
   base::Lock lock_;
 
   MidiPortInfoList input_ports_;
   MidiPortInfoList output_ports_;
 
   DISALLOW_COPY_AND_ASSIGN(MidiManager);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_MIDI_MIDI_MANAGER_H_