Reduce flakiness in EndToEnd probing tests.

webrtc/video/end_to_end_tests.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.
  */
 #include <algorithm>
@@ skipping 2218 matching lines @@
  protected:
   Clock* const clock_;
   const int start_bitrate_bps_;
   int state_;
   Call* sender_call_;
 };
 
 TEST_F(EndToEndTest, MAYBE_InitialProbing) {
   class InitialProbingTest : public ProbingTest {
    public:
-    InitialProbingTest() : ProbingTest(300000) {}
+    explicit InitialProbingTest(bool* success)
+        : ProbingTest(300000), success_(success) {}
 
     void PerformTest() override {
       int64_t start_time_ms = clock_->TimeInMilliseconds();
       do {
-        if (clock_->TimeInMilliseconds() - start_time_ms > kTimeoutMs) {
-          ADD_FAILURE() << "Timed out while waiting for initial probing.";
+        if (clock_->TimeInMilliseconds() - start_time_ms > kTimeoutMs)
           break;
-        }
 
         Call::Stats stats = sender_call_->GetStats();
         // Initial probing is done with a x3 and x6 multiplier of the start
         // bitrate, so a x4 multiplier is a high enough threshold.
-        if (stats.send_bandwidth_bps > 4 * 300000)
+        if (stats.send_bandwidth_bps > 4 * 300000) {
+          *success_ = true;
           break;
+        }
       } while (!observation_complete_.Wait(20));
     }
 
    private:
     const int kTimeoutMs = 1000;
-  } test;
+    bool* const success_;
+  };
 
-  RunBaseTest(&test);
+  bool success;
+  const int kMaxAttempts = 3;
+  for (int i = 0; i < kMaxAttempts; ++i) {
+    InitialProbingTest test(&success);
+    RunBaseTest(&test);
+    if (success)
+      return;
+  }
+  RTC_DCHECK(success) << "Failed to perform mid initial probing ("
+                      << kMaxAttempts << " attempts).";
 }
 
 TEST_F(EndToEndTest, TriggerMidCallProbing) {
   class TriggerMidCallProbingTest : public ProbingTest {
    public:
-    TriggerMidCallProbingTest() : ProbingTest(300000) {}
+    explicit TriggerMidCallProbingTest(bool* success)
+        : ProbingTest(300000), success_(success) {}
 
     void PerformTest() override {
+      *success_ = false;
       int64_t start_time_ms = clock_->TimeInMilliseconds();
       do {
-        if (clock_->TimeInMilliseconds() - start_time_ms > kTimeoutMs) {
-          ADD_FAILURE() << "Timed out while waiting for mid-call probing.";
+        if (clock_->TimeInMilliseconds() - start_time_ms > kTimeoutMs)
           break;
-        }
 
         Call::Stats stats = sender_call_->GetStats();
 
         switch (state_) {
           case 0:
             if (stats.send_bandwidth_bps > 5 * 300000) {
               Call::Config::BitrateConfig bitrate_config;
               bitrate_config.max_bitrate_bps = 100000;
               sender_call_->SetBitrateConfig(bitrate_config);
               ++state_;
             }
             break;
           case 1:
             if (stats.send_bandwidth_bps < 110000) {
               Call::Config::BitrateConfig bitrate_config;
               bitrate_config.max_bitrate_bps = 2500000;
               sender_call_->SetBitrateConfig(bitrate_config);
               ++state_;
             }
             break;
           case 2:
             // During high cpu load the pacer will not be able to pace packets
             // at the correct speed, but if we go from 110 to 1250 kbps
             // in 5 seconds then it is due to probing.
-            if (stats.send_bandwidth_bps > 1250000)
+            if (stats.send_bandwidth_bps > 1250000) {
+              *success_ = true;
               observation_complete_.Set();
+            }
             break;
         }
       } while (!observation_complete_.Wait(20));
     }
 
    private:
     const int kTimeoutMs = 5000;
-  } test;
+    bool* const success_;
+  };
 
-  RunBaseTest(&test);
+  bool success;
+  const int kMaxAttempts = 3;
+  for (int i = 0; i < kMaxAttempts; ++i) {
+    TriggerMidCallProbingTest test(&success);
+    RunBaseTest(&test);
+    if (success)
+      return;
+  }
+  RTC_DCHECK(success) << "Failed to perform mid call probing (" << kMaxAttempts
+                      << " attempts).";
 }
 
 TEST_F(EndToEndTest, VerifyNackStats) {
   static const int kPacketNumberToDrop = 200;
   class NackObserver : public test::EndToEndTest {
    public:
     NackObserver()
         : EndToEndTest(kLongTimeoutMs),
           sent_rtp_packets_(0),
           dropped_rtp_packet_(0),
@@ skipping 1973 matching lines @@
     std::unique_ptr<VideoEncoder> encoder_;
     std::unique_ptr<VideoDecoder> decoder_;
     rtc::CriticalSection crit_;
     int recorded_frames_ GUARDED_BY(crit_);
   } test(this);
 
   RunBaseTest(&test);
 }
 
 }  // namespace webrtc