Move audio output number limit to AudioManager.

media/audio/win/audio_manager_win.cc

 // Copyright (c) 2010 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/audio/audio_io.h"
 
 #include <windows.h>
 #include <objbase.h>  // This has to be before initguid.h
 #include <initguid.h>
 #include <mmsystem.h>
@@ skipping 16 matching lines @@
 // The following are defined in various DDK headers, and we (re)define them
 // here to avoid adding the DDK as a chrome dependency.
 #define DRV_QUERYDEVICEINTERFACE 0x80c
 #define DRVM_MAPPER_PREFERRED_GET 0x2015
 #define DRV_QUERYDEVICEINTERFACESIZE 0x80d
 DEFINE_GUID(AM_KSCATEGORY_AUDIO, 0x6994ad04, 0x93ef, 0x11d0,
             0xa3, 0xcc, 0x00, 0xa0, 0xc9, 0x22, 0x31, 0x96);
 
 namespace {
 
+// Maximum number of output streams that can be open simultaneously.
+const size_t kMaxOutputStreams = 50;
+
 // Up to 8 channels can be passed to the driver.
 // This should work, given the right drivers, but graceful error handling is
 // needed.
 const int kWinMaxChannels = 8;
 
 const int kWinMaxInputChannels = 2;
 // We use 3 buffers for recording audio so that if a recording callback takes
 // some time to return we won't lose audio. More buffers while recording are
 // ok because they don't introduce any delay in recording, unlike in playback
 // where you first need to fill in that number of buffers before starting to
@@ skipping 37 matching lines @@
   }
 
   SetupDiSetDeviceInstallParams(device_info, device_data,
                                 &old_device_install_params);
 
   return device_and_driver_info;
 }
 
 }  // namespace
 
+AudioManagerWin::AudioManagerWin()
+    : num_output_streams_(0) {
+}
+
 bool AudioManagerWin::HasAudioOutputDevices() {
   return (::waveOutGetNumDevs() != 0);
 }
 
 bool AudioManagerWin::HasAudioInputDevices() {
   return (::waveInGetNumDevs() != 0);
 }
 
 // Factory for the implementations of AudioOutputStream. Two implementations
 // should suffice most windows user's needs.
 // - PCMWaveOutAudioOutputStream: Based on the waveOutWrite API (in progress)
 // - PCMDXSoundAudioOutputStream: Based on DirectSound or XAudio (future work).
 AudioOutputStream* AudioManagerWin::MakeAudioOutputStream(
     AudioParameters params) {
   if (!params.IsValid() || (params.channels > kWinMaxChannels))
     return NULL;
 
+  // Limit the number of audio streams opened.
+  if (num_output_streams_ >= kMaxOutputStreams) {
+    return NULL;
+  }
+
   if (params.format == AudioParameters::AUDIO_MOCK) {
     return FakeAudioOutputStream::MakeFakeStream(params);
   } else if (params.format == AudioParameters::AUDIO_PCM_LINEAR) {
+    num_output_streams_++;
     return new PCMWaveOutAudioOutputStream(this, params, 3, WAVE_MAPPER);
   } else if (params.format == AudioParameters::AUDIO_PCM_LOW_LATENCY) {
+    num_output_streams_++;
     // TODO(cpu): waveout cannot hit 20ms latency. Use other method.
     return new PCMWaveOutAudioOutputStream(this, params, 2, WAVE_MAPPER);
   }
   return NULL;
 }
 
 // Factory for the implementations of AudioInputStream.
 AudioInputStream* AudioManagerWin::MakeAudioInputStream(
     AudioParameters params) {
   if (!params.IsValid() || (params.channels > kWinMaxInputChannels))
     return NULL;
 
   if (params.format == AudioParameters::AUDIO_MOCK) {
     return FakeAudioInputStream::MakeFakeStream(params);
   } else if (params.format == AudioParameters::AUDIO_PCM_LINEAR) {
     return new PCMWaveInAudioInputStream(this, params, kNumInputBuffers,
                                          WAVE_MAPPER);
   }
   return NULL;
 }
 
 void AudioManagerWin::ReleaseOutputStream(PCMWaveOutAudioOutputStream* stream) {
-  if (stream)
-    delete stream;
+  DCHECK(stream);
+  num_output_streams_--;
+  delete stream;
 }
 
 void AudioManagerWin::ReleaseInputStream(PCMWaveInAudioInputStream* stream) {
-  if (stream)
-    delete stream;
+  delete stream;
 }
 
 void AudioManagerWin::MuteAll() {
 }
 
 void AudioManagerWin::UnMuteAll() {
 }
 
 AudioManagerWin::~AudioManagerWin() {
 }
@@ skipping 54 matching lines @@
       return GetDeviceAndDriverInfo(device_info, &device_data);
   }
 
   return string16();
 }
 
 // static
 AudioManager* AudioManager::CreateAudioManager() {
   return new AudioManagerWin();
 }