Rewrote the PRNG using an xorshift* algorithm and moved the files from test/ to base/.

webrtc/modules/remote_bitrate_estimator/overuse_detector_unittest.cc

 /*
  *  Copyright (c) 2012 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.
  */
 
 #include <math.h>
 #include <cmath>
 #include <cstdlib>
 
 #include "testing/gtest/include/gtest/gtest.h"
 
+#include "webrtc/base/random.h"
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/common_types.h"
 #include "webrtc/modules/remote_bitrate_estimator/inter_arrival.h"
 #include "webrtc/modules/remote_bitrate_estimator/overuse_detector.h"
 #include "webrtc/modules/remote_bitrate_estimator/overuse_estimator.h"
 #include "webrtc/modules/remote_bitrate_estimator/rate_statistics.h"
 #include "webrtc/test/field_trial.h"
-#include "webrtc/test/random.h"
 #include "webrtc/test/testsupport/gtest_disable.h"
 
 namespace webrtc {
 namespace testing {
 
 const double kRtpTimestampToMs = 1.0 / 90.0;
 
 class OveruseDetectorTest : public ::testing::Test {
  public:
   OveruseDetectorTest()
       : now_ms_(0),
         receive_time_ms_(0),
         rtp_timestamp_(10 * 90),
         overuse_detector_(),
         overuse_estimator_(new OveruseEstimator(options_)),
         inter_arrival_(new InterArrival(5 * 90, kRtpTimestampToMs, true)),
-        random_(1234) {}
+        random_(123456789) {}
 
  protected:
   void SetUp() override {
     overuse_detector_.reset(new OveruseDetector(options_));
   }
 
   int Run100000Samples(int packets_per_frame, size_t packet_size, int mean_ms,
                        int standard_deviation_ms) {
     int unique_overuse = 0;
     int last_overuse = -1;
     for (int i = 0; i < 100000; ++i) {
       for (int j = 0; j < packets_per_frame; ++j) {
         UpdateDetector(rtp_timestamp_, receive_time_ms_, packet_size);
       }
       rtp_timestamp_ += mean_ms * 90;
       now_ms_ += mean_ms;
-      receive_time_ms_ =
-          std::max(receive_time_ms_,
-                   now_ms_ + random_.Gaussian(0, standard_deviation_ms));
+      receive_time_ms_ = std::max<int64_t>(
+          receive_time_ms_,
+          now_ms_ + static_cast<int64_t>(
+                        random_.Gaussian(0, standard_deviation_ms) + 0.5));
       if (kBwOverusing == overuse_detector_->State()) {
         if (last_overuse + 1 != i) {
           unique_overuse++;
         }
         last_overuse = i;
       }
     }
     return unique_overuse;
   }
 
   int RunUntilOveruse(int packets_per_frame, size_t packet_size, int mean_ms,
                       int standard_deviation_ms, int drift_per_frame_ms) {
     // Simulate a higher send pace, that is too high.
     for (int i = 0; i < 1000; ++i) {
       for (int j = 0; j < packets_per_frame; ++j) {
         UpdateDetector(rtp_timestamp_, receive_time_ms_, packet_size);
       }
       rtp_timestamp_ += mean_ms * 90;
       now_ms_ += mean_ms + drift_per_frame_ms;
-      receive_time_ms_ =
-          std::max(receive_time_ms_,
-                   now_ms_ + random_.Gaussian(0, standard_deviation_ms));
+      receive_time_ms_ = std::max<int64_t>(
+          receive_time_ms_,
+          now_ms_ + static_cast<int64_t>(
+                        random_.Gaussian(0, standard_deviation_ms) + 0.5));
       if (kBwOverusing == overuse_detector_->State()) {
         return i + 1;
       }
     }
     return -1;
   }
 
   void UpdateDetector(uint32_t rtp_timestamp, int64_t receive_time_ms,
                       size_t packet_size) {
     uint32_t timestamp_delta;
@@ skipping 14 matching lines @@
     }
   }
 
   int64_t now_ms_;
   int64_t receive_time_ms_;
   uint32_t rtp_timestamp_;
   OverUseDetectorOptions options_;
   rtc::scoped_ptr<OveruseDetector> overuse_detector_;
   rtc::scoped_ptr<OveruseEstimator> overuse_estimator_;
   rtc::scoped_ptr<InterArrival> inter_arrival_;
-  test::Random random_;
+  Random random_;
 };
 
 TEST_F(OveruseDetectorTest, GaussianRandom) {
   int buckets[100];
   memset(buckets, 0, sizeof(buckets));
   for (int i = 0; i < 100000; ++i) {
     int index = random_.Gaussian(49, 10);
     if (index >= 0 && index < 100)
       buckets[index]++;
   }
@@ skipping 87 matching lines @@
   uint32_t drift_per_frame_ms = 10;
   uint32_t rtp_timestamp = frame_duration_ms * 90;
   size_t packet_size = 1200;
   int offset = 10;
 
   // Run 1000 samples to reach steady state.
   for (int i = 0; i < 1000; ++i) {
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
     rtp_timestamp += frame_duration_ms * 90;
     if (i % 2) {
-      offset = rand() % 50;
+      offset = random_.Rand(0, 49);
       now_ms_ += frame_duration_ms - offset;
     } else {
       now_ms_ += frame_duration_ms + offset;
     }
     EXPECT_EQ(kBwNormal, overuse_detector_->State());
   }
   // Simulate a higher send pace, that is too high.
   // Above noise generate a standard deviation of approximately 28 ms.
   // Total build up of 150 ms.
   for (int j = 0; j < 15; ++j) {
@@ skipping 11 matching lines @@
   uint32_t drift_per_frame_ms = 1;
   uint32_t rtp_timestamp = frame_duration_ms * 90;
   size_t packet_size = 1200;
   int offset = 10;
 
   // Run 1000 samples to reach steady state.
   for (int i = 0; i < 1000; ++i) {
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
     rtp_timestamp += frame_duration_ms * 90;
     if (i % 2) {
-      offset = rand() % 2;
+      offset = random_.Rand(0, 1);
       now_ms_ += frame_duration_ms - offset;
     } else {
       now_ms_ += frame_duration_ms + offset;
     }
     EXPECT_EQ(kBwNormal, overuse_detector_->State());
   }
   // Simulate a higher send pace, that is too high.
   // Total build up of 6 ms.
   for (int j = 0; j < 6; ++j) {
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
@@ skipping 15 matching lines @@
   // Run 1000 samples to reach steady state.
   for (int i = 0; i < 1000; ++i) {
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
     rtp_timestamp += frame_duration_ms * 90;
     if (i % 2) {
-      offset = rand() % 2;
+      offset = random_.Rand(0, 1);
       now_ms_ += frame_duration_ms - offset;
     } else {
       now_ms_ += frame_duration_ms + offset;
     }
     EXPECT_EQ(kBwNormal, overuse_detector_->State());
   }
   // Simulate a higher send pace, that is too high.
   // Total build up of 30 ms.
   for (int j = 0; j < 5; ++j) {
     UpdateDetector(rtp_timestamp, now_ms_, packet_size);
@@ skipping 12 matching lines @@
 
 TEST_F(OveruseDetectorTest,
        DISABLED_ON_ANDROID(LowGaussianVariance30Kbit3fps)) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 333;
   int drift_per_frame_ms = 1;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
-  EXPECT_EQ(13, unique_overuse);
+  EXPECT_EQ(1, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(14, frames_until_overuse);
+  EXPECT_EQ(13, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, LowGaussianVarianceFastDrift30Kbit3fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 333;
   int drift_per_frame_ms = 100;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
-  EXPECT_EQ(13, unique_overuse);
+  EXPECT_EQ(1, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
   EXPECT_EQ(4, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, HighGaussianVariance30Kbit3fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 333;
   int drift_per_frame_ms = 1;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
-  EXPECT_EQ(46, unique_overuse);
+  EXPECT_EQ(1, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(42, frames_until_overuse);
+  EXPECT_EQ(32, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, HighGaussianVarianceFastDrift30Kbit3fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 333;
   int drift_per_frame_ms = 100;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
-  EXPECT_EQ(46, unique_overuse);
+  EXPECT_EQ(1, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
   EXPECT_EQ(4, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest,
        DISABLED_ON_ANDROID(LowGaussianVariance100Kbit5fps)) {
   size_t packet_size = 1200;
   int packets_per_frame = 2;
   int frame_duration_ms = 200;
   int drift_per_frame_ms = 1;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
-  EXPECT_EQ(12, unique_overuse);
+  EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(12, frames_until_overuse);
+  EXPECT_EQ(13, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest,
        DISABLED_ON_ANDROID(HighGaussianVariance100Kbit5fps)) {
   size_t packet_size = 1200;
   int packets_per_frame = 2;
   int frame_duration_ms = 200;
   int drift_per_frame_ms = 1;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
-  EXPECT_EQ(16, unique_overuse);
+  EXPECT_EQ(1, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(37, frames_until_overuse);
+  EXPECT_EQ(32, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest,
        DISABLED_ON_ANDROID(LowGaussianVariance100Kbit10fps)) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 100;
   int drift_per_frame_ms = 1;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
-  EXPECT_EQ(12, unique_overuse);
+  EXPECT_EQ(1, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(12, frames_until_overuse);
+  EXPECT_EQ(13, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest,
        DISABLED_ON_ANDROID(HighGaussianVariance100Kbit10fps)) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 100;
   int drift_per_frame_ms = 1;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
-  EXPECT_EQ(12, unique_overuse);
+  EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(37, frames_until_overuse);
+  EXPECT_EQ(32, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest,
        DISABLED_ON_ANDROID(LowGaussianVariance300Kbit30fps)) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 1;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(14, frames_until_overuse);
+  EXPECT_EQ(15, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, LowGaussianVarianceFastDrift300Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 10;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
   EXPECT_EQ(6, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, HighGaussianVariance300Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 1;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(49, frames_until_overuse);
+  EXPECT_EQ(41, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, HighGaussianVarianceFastDrift300Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 1;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 10;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(8, frames_until_overuse);
+  EXPECT_EQ(10, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest,
        DISABLED_ON_ANDROID(LowGaussianVariance1000Kbit30fps)) {
   size_t packet_size = 1200;
   int packets_per_frame = 3;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 1;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(14, frames_until_overuse);
+  EXPECT_EQ(15, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, LowGaussianVarianceFastDrift1000Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 3;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 10;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
   EXPECT_EQ(6, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, HighGaussianVariance1000Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 3;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 1;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(49, frames_until_overuse);
+  EXPECT_EQ(41, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, HighGaussianVarianceFastDrift1000Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 3;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 10;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(8, frames_until_overuse);
+  EXPECT_EQ(10, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest,
        DISABLED_ON_ANDROID(LowGaussianVariance2000Kbit30fps)) {
   size_t packet_size = 1200;
   int packets_per_frame = 6;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 1;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(14, frames_until_overuse);
+  EXPECT_EQ(15, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, LowGaussianVarianceFastDrift2000Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 6;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 10;
   int sigma_ms = 3;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
   EXPECT_EQ(6, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, HighGaussianVariance2000Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 6;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 1;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(49, frames_until_overuse);
+  EXPECT_EQ(41, frames_until_overuse);
 }
 
 TEST_F(OveruseDetectorTest, HighGaussianVarianceFastDrift2000Kbit30fps) {
   size_t packet_size = 1200;
   int packets_per_frame = 6;
   int frame_duration_ms = 33;
   int drift_per_frame_ms = 10;
   int sigma_ms = 10;
   int unique_overuse = Run100000Samples(packets_per_frame, packet_size,
                                         frame_duration_ms, sigma_ms);
   EXPECT_EQ(0, unique_overuse);
   int frames_until_overuse = RunUntilOveruse(packets_per_frame, packet_size,
       frame_duration_ms, sigma_ms, drift_per_frame_ms);
-  EXPECT_EQ(8, frames_until_overuse);
+  EXPECT_EQ(10, frames_until_overuse);
 }
 
 class OveruseDetectorExperimentTest : public OveruseDetectorTest {
  public:
   OveruseDetectorExperimentTest()
       : override_field_trials_(
             "WebRTC-AdaptiveBweThreshold/Enabled-0.01,0.00018/") {}
 
  protected:
   void SetUp() override {
@@ skipping 118 matching lines @@
     if (overuse_state == kBwOverusing) {
       overuse_detected = true;
     }
     ++num_deltas;
     now_ms += 5;
   }
   EXPECT_TRUE(overuse_detected);
 }
 }  // namespace testing
 }  // namespace webrtc