Move audio output number limit to AudioManager.

chrome/browser/renderer_host/audio_renderer_host.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 "chrome/browser/renderer_host/audio_renderer_host.h"
 
 #include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/shared_memory.h"
-#include "base/sys_info.h"
 #include "chrome/browser/renderer_host/audio_sync_reader.h"
 #include "chrome/common/render_messages.h"
 #include "chrome/common/render_messages_params.h"
 #include "ipc/ipc_logging.h"
 
 // The minimum number of samples in a hardware packet.
 // This value is selected so that we can handle down to 5khz sample rate.
 static const int kMinSamplesPerHardwarePacket = 1024;
 
 // The maximum number of samples in a hardware packet.
 // This value is selected so that we can handle up to 192khz sample rate.
 static const int kMaxSamplesPerHardwarePacket = 64 * 1024;
 
 // This constant governs the hardware audio buffer size, this value should be
 // chosen carefully.
 // This value is selected so that we have 8192 samples for 48khz streams.
 static const int kMillisecondsPerHardwarePacket = 170;
 
-// We allow at most 50 concurrent audio streams in most case. This is a
-// rather high limit that is practically hard to reach.
-static const size_t kMaxStreams = 50;
-
-// By experiment the maximum number of audio streams allowed in Leopard
-// is 18. But we put a slightly smaller number just to be safe.
-static const size_t kMaxStreamsLeopard = 15;
-
-// Returns the number of audio streams allowed. This is a practical limit to
-// prevent failure caused by too many audio streams opened.
-static size_t GetMaxAudioStreamsAllowed() {
-#if defined(OS_MACOSX)
-  // We are hitting a bug in Leopard where too many audio streams will cause
-  // a deadlock in the AudioQueue API when starting the stream. Unfortunately
-  // there's no way to detect it within the AudioQueue API, so we put a
-  // special hard limit only for Leopard.
-  // See bug: http://crbug.com/30242
-  int32 major, minor, bugfix;
-  base::SysInfo::OperatingSystemVersionNumbers(&major, &minor, &bugfix);
-  if (major < 10 || (major == 10 && minor <= 5))
-    return kMaxStreamsLeopard;
-#endif
-
-  // In OS other than OSX Leopard, the number of audio streams allowed is a
-  // lot more so we return a separate number.
-  return kMaxStreams;
-}
-
 static uint32 SelectSamplesPerPacket(AudioParameters params) {
   // Select the number of samples that can provide at least
   // |kMillisecondsPerHardwarePacket| worth of audio data.
   int samples = kMinSamplesPerHardwarePacket;
   while (samples <= kMaxSamplesPerHardwarePacket &&
          samples * base::Time::kMillisecondsPerSecond <
          params.sample_rate * kMillisecondsPerHardwarePacket) {
     samples *= 2;
   }
   return samples;
@@ skipping 263 matching lines @@
     }
     return false;
 }
 
 void AudioRendererHost::OnCreateStream(
     const IPC::Message& msg, int stream_id,
     const ViewHostMsg_Audio_CreateStream_Params& params, bool low_latency) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(LookupById(msg.routing_id(), stream_id) == NULL);
 
-  // Limit the number of audio streams opened. This is to prevent using
-  // excessive resources for a large number of audio streams. More
-  // importantly it prevents instability on certain systems.
-  // See bug: http://crbug.com/30242
-  if (audio_entries_.size() >= GetMaxAudioStreamsAllowed()) {
-    SendErrorMessage(msg.routing_id(), stream_id);
-    return;
-  }
-
   AudioParameters audio_params(params.params);
 
   // Select the hardware packet size if not specified.
   if (!audio_params.samples_per_packet) {
     audio_params.samples_per_packet = SelectSamplesPerPacket(audio_params);
   }
   uint32 packet_size = audio_params.GetPacketSize();
 
   scoped_ptr<AudioEntry> entry(new AudioEntry());
   // Create the shared memory and share with the renderer process.
@@ skipping 221 matching lines @@
 
   // Iterate the map of entries.
   // TODO(hclam): Implement a faster look up method.
   for (AudioEntryMap::iterator i = audio_entries_.begin();
        i != audio_entries_.end(); ++i) {
     if (controller == i->second->controller.get())
       return i->second;
   }
   return NULL;
 }