Limits only 16 new QUIC connections can be opened per epoll event.

net/tools/quic/end_to_end_test.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <sys/epoll.h>
 
 #include <list>
 #include <memory>
 #include <string>
@@ skipping 480 matching lines @@
   void TearDown() override {
     ASSERT_TRUE(initialized_) << "You must call Initialize() in every test "
                               << "case. Otherwise, your test will leak memory.";
     StopServer();
   }
 
   void StartServer() {
     FLAGS_quic_buffer_packet_till_chlo = GetParam().buffer_packet_till_chlo;
     FLAGS_quic_use_cheap_stateless_rejects =
         GetParam().use_cheap_stateless_reject;
+    if (!FLAGS_quic_buffer_packet_till_chlo) {
+      FLAGS_quic_limit_num_new_sessions_per_epoll_loop = false;
+    }
     auto test_server =
         new QuicTestServer(CryptoTestUtils::ProofSourceForTesting(),
                            server_config_, server_supported_versions_);
     if (GetParam().small_client_mtu) {
       FLAGS_quic_enforce_mtu_limit = true;
       QuicServerPeer::SetReader(test_server, new SmallMtuPacketReader);
       server_writer_->set_max_allowed_packet_size(kMinimumSupportedPacketSize);
     }
     server_thread_.reset(new ServerThread(test_server, server_address_,
                                           strike_register_no_startup_period_));
@@ skipping 2405 matching lines @@
   EXPECT_EQ(kBarResponseBody, client_->response_body());
   QuicConnectionStats client_stats =
       client_->client()->session()->connection()->GetStats();
   EXPECT_EQ(0u, client_stats.packets_lost);
   EXPECT_EQ(1, client_->client()->GetNumSentClientHellos());
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace net