Moves channel-dependent audio input processing to separate encoder task queue

webrtc/base/swap_queue.h

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 86 matching lines @@
   }
 
   // Same as above and accepts an item verification functor.
   SwapQueue(size_t size,
             const T& prototype,
             const QueueItemVerifier& queue_item_verifier)
       : queue_item_verifier_(queue_item_verifier), queue_(size, prototype) {
     RTC_DCHECK(VerifyQueueSlots());
   }
 
+  size_t Capacity() const { return queue_.size(); }
+
+  size_t Size() const {
+    rtc::CritScope cs(&crit_queue_);
+    return num_elements_;

[tommi, 2017/03/28 13:01:40]

returning a value that requires a lock?  (the returned value can't be assumed to
be correct, since a lock isn't held when examined).  Can we instead require that
the calling thread is the same thread as the value can change on?

+  }
+
   // Resets the queue to have zero content wile maintaining the queue size.
   void Clear() {
     rtc::CritScope cs(&crit_queue_);
     next_write_index_ = 0;
     next_read_index_ = 0;
     num_elements_ = 0;
   }
 
   // Inserts a "full" T at the back of the queue by swapping *input with an
   // "empty" T from the queue.
@@ skipping 85 matching lines @@
 
   // queue_.size() is constant.
   std::vector<T> queue_ GUARDED_BY(crit_queue_);
 
   RTC_DISALLOW_COPY_AND_ASSIGN(SwapQueue);
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_BASE_SWAP_QUEUE_H_