Avoid busy looping in case of send failure when probing.

webrtc/modules/pacing/paced_sender_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.
  */
 
@@ skipping 1028 matching lines @@
   const int kNotAProbe = PacedPacketInfo::kNotAProbe;
   // No more probing packets.
   EXPECT_CALL(callback_,
               TimeToSendPadding(
                   _, Field(&PacedPacketInfo::probe_cluster_id, kNotAProbe)))
       .Times(1)
       .WillRepeatedly(Return(500));
   send_bucket_->Process();
 }
 
+TEST_F(PacedSenderTest, AvoidBusyLoopOnSendFailure) {
+  uint32_t ssrc = 12346;
+  uint16_t sequence_number = 1234;
+  const size_t kPacketSize = kFirstClusterBps / (8000 / 10);
+
+  send_bucket_->SetSendBitrateLimits(kTargetBitrateBps, kTargetBitrateBps);
+  send_bucket_->SetProbingEnabled(true);
+  send_bucket_->InsertPacket(PacedSender::kNormalPriority, ssrc,
+                             sequence_number, clock_.TimeInMilliseconds(),
+                             kPacketSize, false);
+
+  EXPECT_CALL(callback_, TimeToSendPacket(_, _, _, _, _))
+      .WillOnce(Return(true));
+  send_bucket_->Process();
+  EXPECT_EQ(10, send_bucket_->TimeUntilNextProcess());
+  clock_.AdvanceTimeMilliseconds(9);
+
+  EXPECT_CALL(callback_, TimeToSendPadding(_, _))
+      .Times(2)
+      .WillRepeatedly(Return(0));
+  send_bucket_->Process();
+  EXPECT_EQ(1, send_bucket_->TimeUntilNextProcess());
+  clock_.AdvanceTimeMilliseconds(1);
+  send_bucket_->Process();
+  EXPECT_EQ(5, send_bucket_->TimeUntilNextProcess());
+}
+
 }  // namespace test
 }  // namespace webrtc