Reland of Delete class SSRCDatabase, and its global ssrc registry.

webrtc/modules/rtp_rtcp/source/ssrc_database.h

-/*
- *  Copyright (c) 2011 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.
- */
-
-#ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_SSRC_DATABASE_H_
-#define WEBRTC_MODULES_RTP_RTCP_SOURCE_SSRC_DATABASE_H_
-
-#include <set>
-
-#include "webrtc/base/criticalsection.h"
-#include "webrtc/base/random.h"
-#include "webrtc/base/thread_annotations.h"
-#include "webrtc/system_wrappers/include/static_instance.h"
-#include "webrtc/typedefs.h"
-
-namespace webrtc {
-
-// TODO(tommi, holmer): Look into whether we can eliminate locking in this
-// class or the class itself completely once voice engine doesn't rely on it.
-// At the moment voe_auto_test requires locking, but it's not clear if that's
-// an issue with the test code or if it reflects real world usage or if that's
-// the best design performance wise.
-// If we do decide to keep the class, we should at least get rid of using
-// StaticInstance.
-class SSRCDatabase {
- public:
-  static SSRCDatabase* GetSSRCDatabase();
-  static void ReturnSSRCDatabase();
-
-  uint32_t CreateSSRC();
-  void RegisterSSRC(uint32_t ssrc);
-  void ReturnSSRC(uint32_t ssrc);
-
- protected:
-  SSRCDatabase();
-  ~SSRCDatabase();
-
-  static SSRCDatabase* CreateInstance() { return new SSRCDatabase(); }
-
-  // Friend function to allow the SSRC destructor to be accessed from the
-  // template class.
-  friend SSRCDatabase* GetStaticInstance<SSRCDatabase>(
-      CountOperation count_operation);
-
- private:
-  rtc::CriticalSection crit_;
-  Random random_ GUARDED_BY(crit_);
-  std::set<uint32_t> ssrcs_ GUARDED_BY(crit_);
-  // TODO(tommi): Use a thread checker to ensure the object is created and
-  // deleted on the same thread.  At the moment this isn't possible due to
-  // voe::ChannelOwner in voice engine.  To reproduce, run:
-  // voe_auto_test --automated --gtest_filter=*MixManyChannelsForStressOpus
-};
-}  // namespace webrtc
-
-#endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_SSRC_DATABASE_H_