Web MIDI: fix multi-threading problem around message buffer handling

media/midi/midi_manager_mac.cc

 // 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.
 
 #include "media/midi/midi_manager_mac.h"
 
 #include <iostream>
 #include <string>
 
 #include "base/debug/trace_event.h"
@@ skipping 129 matching lines @@
 
     ReceiveMIDIData(
         port_index,
         packet.data,
         packet.length,
         timestamp_seconds);
   }
 }
 
 void MIDIManagerMac::SendMIDIData(MIDIManagerClient* client,
-                                  int port_index,
-                                  const uint8* data,
-                                  size_t length,
+                                  unsigned int port_index,
+                                  const std::vector<uint8>& data,
                                   double timestamp) {
+  DCHECK(CurrentlyOnMIDISendThread());
+
   // System Exclusive has already been filtered.
   MIDITimeStamp coremidi_timestamp = SecondsToMIDITimeStamp(timestamp);
 
   midi_packet_ = MIDIPacketListAdd(
       packet_list_,
       kMaxPacketListSize,
       midi_packet_,
       coremidi_timestamp,
-      length,
-      data);
+      data.size(),
+      &data[0]);
 
   // Lookup the destination based on the port index.
-  // TODO(crogers): re-factor |port_index| to use unsigned
-  // to avoid the need for this check.
-  if (port_index < 0 ||
-      static_cast<size_t>(port_index) >= destinations_.size())
+  if (static_cast<size_t>(port_index) >= destinations_.size())

[scherkus (not reviewing), 2013/08/21 17:46:29]

if you make port_index size_t, you can remove the cast

[Takashi Toyoshima, 2013/08/22 05:47:45]

Done.

     return;
 
   MIDIEndpointRef destination = destinations_[port_index];
 
   MIDISend(coremidi_output_, destination, packet_list_);
 
   // Re-initialize for next time.
   midi_packet_ = MIDIPacketListInit(packet_list_);
 
-  client->AccumulateMIDIBytesSent(length);
+  client->AccumulateMIDIBytesSent(data.size());
 }
 
 MIDIPortInfo MIDIManagerMac::GetPortInfoFromEndpoint(
     MIDIEndpointRef endpoint) {
   SInt32 id_number = 0;
   MIDIObjectGetIntegerProperty(endpoint, kMIDIPropertyUniqueID, &id_number);
   string id = IntToString(id_number);
 
   CFStringRef manufacturer_ref = NULL;
   MIDIObjectGetStringProperty(
@@ skipping 16 matching lines @@
   UInt64 nanoseconds = AudioConvertHostTimeToNanos(timestamp);
   return static_cast<double>(nanoseconds) / 1.0e9;
 }
 
 MIDITimeStamp MIDIManagerMac::SecondsToMIDITimeStamp(double seconds) {
   UInt64 nanos = UInt64(seconds * 1.0e9);
   return AudioConvertNanosToHostTime(nanos);
 }
 
 }  // namespace media