Shrink critical-section scope in ReceiveStatisticsImpl::GetActiveStatisticians()

webrtc/modules/rtp_rtcp/source/receive_statistics_impl.cc

 /*
  *  Copyright (c) 2013 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 404 matching lines @@
                                               size_t packet_length) {
   rtc::CritScope cs(&receive_statistics_lock_);
   StatisticianImplMap::iterator it = statisticians_.find(header.ssrc);
   // Ignore FEC if it is the first packet.
   if (it != statisticians_.end()) {
     it->second->FecPacketReceived(header, packet_length);
   }
 }
 
 StatisticianMap ReceiveStatisticsImpl::GetActiveStatisticians() const {
-  rtc::CritScope cs(&receive_statistics_lock_);
   StatisticianMap active_statisticians;
-  for (StatisticianImplMap::const_iterator it = statisticians_.begin();
-       it != statisticians_.end(); ++it) {
-    uint32_t secs;
-    uint32_t frac;
-    it->second->LastReceiveTimeNtp(&secs, &frac);
-    if (clock_->CurrentNtpInMilliseconds() -
-        Clock::NtpToMs(secs, frac) < kStatisticsTimeoutMs) {
-      active_statisticians[it->first] = it->second;
+
+  {

[danilchap, 2017/07/25 14:05:41]

I think extra indentation make it less readable.
specially that you do not need it.

[eladalon, 2017/07/25 14:28:49]

I'm not sure I don't need this - I am not familiar enough with what operations
return-StatisticianMap would trigger if RVO is not used, and what part of this
is compiler-dependent and what is mandated by C++. But it's probably not
important enough, and given that this is already an improvement over the state
before, I'll change.

+    rtc::CritScope cs(&receive_statistics_lock_);
+    for (StatisticianImplMap::const_iterator it = statisticians_.begin();
+         it != statisticians_.end(); ++it) {
+      uint32_t secs;
+      uint32_t frac;
+      it->second->LastReceiveTimeNtp(&secs, &frac);
+      if (clock_->CurrentNtpInMilliseconds() -
+          Clock::NtpToMs(secs, frac) < kStatisticsTimeoutMs) {
+        active_statisticians[it->first] = it->second;
+      }
     }
   }
+
   return active_statisticians;
 }
 
 StreamStatistician* ReceiveStatisticsImpl::GetStatistician(
     uint32_t ssrc) const {
   rtc::CritScope cs(&receive_statistics_lock_);
   StatisticianImplMap::const_iterator it = statisticians_.find(ssrc);
   if (it == statisticians_.end())
     return NULL;
   return it->second;
@@ skipping 64 matching lines @@
 void NullReceiveStatistics::SetMaxReorderingThreshold(
     int max_reordering_threshold) {}
 
 void NullReceiveStatistics::RegisterRtcpStatisticsCallback(
     RtcpStatisticsCallback* callback) {}
 
 void NullReceiveStatistics::RegisterRtpStatisticsCallback(
     StreamDataCountersCallback* callback) {}
 
 }  // namespace webrtc