3 * Copyright 2017 gRPC authors.
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
26 #include <gmock/gmock.h>
28 #include <grpc/grpc.h>
29 #include <grpc/support/alloc.h>
30 #include <grpc/support/log.h>
31 #include <grpc/support/string_util.h>
32 #include <grpc/support/time.h>
33 #include <grpcpp/channel.h>
34 #include <grpcpp/client_context.h>
35 #include <grpcpp/create_channel.h>
36 #include <grpcpp/impl/codegen/sync.h>
37 #include <grpcpp/server.h>
38 #include <grpcpp/server_builder.h>
40 #include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_balancer_addresses.h"
41 #include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
42 #include "src/core/ext/filters/client_channel/server_address.h"
43 #include "src/core/lib/address_utils/parse_address.h"
44 #include "src/core/lib/gprpp/ref_counted_ptr.h"
45 #include "src/core/lib/gprpp/thd.h"
46 #include "src/core/lib/iomgr/sockaddr.h"
47 #include "test/core/util/port.h"
48 #include "test/core/util/test_config.h"
52 void TryConnectAndDestroy() {
53 auto response_generator =
54 grpc_core::MakeRefCounted<grpc_core::FakeResolverResponseGenerator>();
55 // Return a grpclb address with an IP address on the IPv6 discard prefix
56 // (https://tools.ietf.org/html/rfc6666). This is important because
57 // the behavior we want in this test is for a TCP connect attempt to "freeze",
58 // i.e. we want to send SYN, and then *not* receive SYN-ACK or RST.
59 // The precise behavior is dependant on the test runtime environment though,
60 // since connect() attempts on this address may unfortunately result in
61 // "network unreachable" errors in some test runtime environments.
62 absl::StatusOr<grpc_core::URI> lb_uri =
63 grpc_core::URI::Parse("ipv6:[0100::1234]:443");
64 ASSERT_TRUE(lb_uri.ok());
65 grpc_resolved_address address;
66 ASSERT_TRUE(grpc_parse_uri(*lb_uri, &address));
67 grpc_core::ServerAddressList addresses;
68 addresses.emplace_back(address.addr, address.len, nullptr);
69 grpc_core::Resolver::Result lb_address_result;
70 grpc_error_handle error = GRPC_ERROR_NONE;
71 lb_address_result.service_config = grpc_core::ServiceConfig::Create(
72 nullptr, "{\"loadBalancingConfig\":[{\"grpclb\":{}}]}", &error);
73 ASSERT_EQ(error, GRPC_ERROR_NONE) << grpc_error_std_string(error);
74 grpc_arg arg = grpc_core::CreateGrpclbBalancerAddressesArg(&addresses);
75 lb_address_result.args = grpc_channel_args_copy_and_add(nullptr, &arg, 1);
76 response_generator->SetResponse(lb_address_result);
77 grpc::ChannelArguments args;
78 args.SetPointer(GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR,
79 response_generator.get());
80 // Explicitly set the connect deadline to the same amount of
81 // time as the WaitForConnected time. The goal is to get the
82 // connect timeout code to run at about the same time as when
83 // the channel gets destroyed, to try to reproduce a race.
84 args.SetInt("grpc.testing.fixed_reconnect_backoff_ms",
85 grpc_test_slowdown_factor() * 100);
86 std::ostringstream uri;
87 uri << "fake:///servername_not_used";
88 auto channel = ::grpc::CreateCustomChannel(
89 uri.str(), grpc::InsecureChannelCredentials(), args);
90 // Start connecting, and give some time for the TCP connection attempt to the
91 // unreachable balancer to begin. The connection should never become ready
92 // because the LB we're trying to connect to is unreachable.
93 channel->GetState(true /* try_to_connect */);
95 channel->WaitForConnected(grpc_timeout_milliseconds_to_deadline(100)));
96 ASSERT_EQ("grpclb", channel->GetLoadBalancingPolicyName());
100 TEST(DestroyGrpclbChannelWithActiveConnectStressTest,
101 LoopTryConnectAndDestroy) {
103 std::vector<std::unique_ptr<std::thread>> threads;
104 // 100 is picked for number of threads just
105 // because it's enough to reproduce a certain crash almost 100%
106 // at this time of writing.
107 const int kNumThreads = 100;
108 threads.reserve(kNumThreads);
109 for (int i = 0; i < kNumThreads; i++) {
110 threads.emplace_back(new std::thread(TryConnectAndDestroy));
112 for (size_t i = 0; i < threads.size(); i++) {
120 int main(int argc, char** argv) {
121 grpc::testing::TestEnvironment env(argc, argv);
122 ::testing::InitGoogleTest(&argc, argv);
123 auto result = RUN_ALL_TESTS();