Less lock acquisitions for AudioMixer.

webrtc/modules/audio_mixer/test/audio_mixer_unittest.cc

Index: webrtc/modules/audio_mixer/test/audio_mixer_unittest.cc
diff --git a/webrtc/modules/audio_mixer/test/audio_mixer_unittest.cc b/webrtc/modules/audio_mixer/test/audio_mixer_unittest.cc
index 36bd7c4211e6a9fc0398dfebe3773b91e69a4a1b..9a51e911f7202b193abb50e4ccc73042c759383c 100644
--- a/webrtc/modules/audio_mixer/test/audio_mixer_unittest.cc
+++ b/webrtc/modules/audio_mixer/test/audio_mixer_unittest.cc
@@ -8,6 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
+#include <cstring>

[ivoc, 2016/08/31 14:34:25]

I think we generally use the <string.h> style for C headers.

[aleloi, 2016/08/31 15:16:22]

Seems like that. 21 matches for cstring and 243 for string.h in the code base.
Also, no matches for std::memcmp, but lots of matches for just memcmp.
Done.

 #include <memory>
 #include <utility>
 
@@ -202,6 +203,65 @@ TEST(AudioMixer, LargestEnergyVadActiveMixed) {
   }
 }
 
+TEST(AudioMixer, FrameNotModifiedForSingleParticipant) {
+  const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));
+
+  MockMixerAudioSource participant;
+
+  ResetFrame(participant.fake_frame());
+  const int n_samples = participant.fake_frame()->samples_per_channel_;
+
+  // Modify the frame so that it's not zero.
+  for (int j = 0; j < n_samples; j++) {
+    participant.fake_frame()->data_[j] = j;
+  }
+
+  EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
+  EXPECT_CALL(participant, GetAudioFrameWithMuted(_, _)).Times(Exactly(2));
+
+  AudioFrame audio_frame;
+  // Two mix iteration to compare after the ramp-up step.
+  for (int i = 0; i < 2; i++) {
+    mixer->Mix(kDefaultSampleRateHz,
+               1,  // number of channels
+               &audio_frame);
+  }
+
+  EXPECT_EQ(std::memcmp(participant.fake_frame()->data_, audio_frame.data_,

[ivoc, 2016/08/31 14:34:24]

Please change the order, i.e. EXPECT_EQ(0, std::memcmp(...));

[aleloi, 2016/08/31 15:16:22]

Done. I also changed in a few other tests.

+                        n_samples),
+            0);
+}
+
+TEST(AudioMixer, FrameNotModifiedForSingleAnonymousParticipant) {

[aleloi, 2016/08/31 11:07:46]

This test compares mixer output in the anonymous case. It fails if the line
|MixAnonomouslyFromList(audio_frame_for_mixing, additionalFramesList);| is
removed.

Previously, there were a few tests that compared audio output with the old
mixer. They didn't use anonymous participants. 

+  const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));
+
+  MockMixerAudioSource participant;
+
+  ResetFrame(participant.fake_frame());
+  const int n_samples = participant.fake_frame()->samples_per_channel_;
+
+  // Modify the frame so that it's not zero.
+  for (int j = 0; j < n_samples; j++) {
+    participant.fake_frame()->data_[j] = j;
+  }
+
+  EXPECT_EQ(0, mixer->SetMixabilityStatus(&participant, true));
+  EXPECT_EQ(0, mixer->SetAnonymousMixabilityStatus(&participant, true));
+  EXPECT_CALL(participant, GetAudioFrameWithMuted(_, _)).Times(Exactly(2));
+
+  AudioFrame audio_frame;
+  // Two mix iteration to compare after the ramp-up step.
+  for (int i = 0; i < 2; i++) {
+    mixer->Mix(kDefaultSampleRateHz,
+               1,  // number of channels
+               &audio_frame);
+  }
+
+  EXPECT_EQ(std::memcmp(participant.fake_frame()->data_, audio_frame.data_,

[ivoc, 2016/08/31 14:34:24]

Same here.

[aleloi, 2016/08/31 15:16:22]

Done.

+                        n_samples),
+            0);
+}
+
 TEST(AudioMixer, ParticipantSampleRate) {
   const std::unique_ptr<AudioMixer> mixer(AudioMixer::Create(kId));