1 /*
2 *
3 * Copyright 2017 gRPC authors.
4 *
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
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
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.
16 *
17 */
18
19 #include <atomic>
20 #include <memory>
21 #include <mutex>
22 #include <random>
23 #include <sstream>
24 #include <thread>
25
26 #include <gmock/gmock.h>
27
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>
39
40 #include "src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb_balancer_addresses.h"
41 #include "src/core/ext/filters/client_channel/parse_address.h"
42 #include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
43 #include "src/core/ext/filters/client_channel/server_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
48 #include "test/core/util/port.h"
49 #include "test/core/util/test_config.h"
50
51 namespace {
52
TryConnectAndDestroy()53 void TryConnectAndDestroy() {
54 auto response_generator =
55 grpc_core::MakeRefCounted<grpc_core::FakeResolverResponseGenerator>();
56 // Return a grpclb address with an IP address on the IPv6 discard prefix
57 // (https://tools.ietf.org/html/rfc6666). This is important because
58 // the behavior we want in this test is for a TCP connect attempt to "hang",
59 // i.e. we want to send SYN, and then *not* receive SYN-ACK or RST.
60 // The precise behavior is dependant on the test runtime environment though,
61 // since connect() attempts on this address may unfortunately result in
62 // "network unreachable" errors in some test runtime environments.
63 const char* uri_str = "ipv6:[0100::1234]:443";
64 grpc_uri* lb_uri = grpc_uri_parse(uri_str, true);
65 ASSERT_NE(lb_uri, nullptr);
66 grpc_resolved_address address;
67 ASSERT_TRUE(grpc_parse_uri(lb_uri, &address));
68 grpc_uri_destroy(lb_uri);
69 grpc_core::ServerAddressList addresses;
70 addresses.emplace_back(address.addr, address.len, nullptr);
71 grpc_core::Resolver::Result lb_address_result;
72 grpc_error* error = GRPC_ERROR_NONE;
73 lb_address_result.service_config = grpc_core::ServiceConfig::Create(
74 "{\"loadBalancingConfig\":[{\"grpclb\":{}}]}", &error);
75 ASSERT_EQ(error, GRPC_ERROR_NONE) << grpc_error_string(error);
76 grpc_arg arg = grpc_core::CreateGrpclbBalancerAddressesArg(&addresses);
77 lb_address_result.args = grpc_channel_args_copy_and_add(nullptr, &arg, 1);
78 response_generator->SetResponse(lb_address_result);
79 grpc::ChannelArguments args;
80 args.SetPointer(GRPC_ARG_FAKE_RESOLVER_RESPONSE_GENERATOR,
81 response_generator.get());
82 // Explicitly set the connect deadline to the same amount of
83 // time as the WaitForConnected time. The goal is to get the
84 // connect timeout code to run at about the same time as when
85 // the channel gets destroyed, to try to reproduce a race.
86 args.SetInt("grpc.testing.fixed_reconnect_backoff_ms",
87 grpc_test_slowdown_factor() * 100);
88 std::ostringstream uri;
89 uri << "fake:///servername_not_used";
90 auto channel = ::grpc::CreateCustomChannel(
91 uri.str(), grpc::InsecureChannelCredentials(), args);
92 // Start connecting, and give some time for the TCP connection attempt to the
93 // unreachable balancer to begin. The connection should never become ready
94 // because the LB we're trying to connect to is unreachable.
95 channel->GetState(true /* try_to_connect */);
96 ASSERT_FALSE(
97 channel->WaitForConnected(grpc_timeout_milliseconds_to_deadline(100)));
98 ASSERT_EQ("grpclb", channel->GetLoadBalancingPolicyName());
99 channel.reset();
100 };
101
TEST(DestroyGrpclbChannelWithActiveConnectStressTest,LoopTryConnectAndDestroy)102 TEST(DestroyGrpclbChannelWithActiveConnectStressTest,
103 LoopTryConnectAndDestroy) {
104 grpc_init();
105 std::vector<std::unique_ptr<std::thread>> threads;
106 // 100 is picked for number of threads just
107 // because it's enough to reproduce a certain crash almost 100%
108 // at this time of writing.
109 const int kNumThreads = 100;
110 threads.reserve(kNumThreads);
111 for (int i = 0; i < kNumThreads; i++) {
112 threads.emplace_back(new std::thread(TryConnectAndDestroy));
113 }
114 for (int i = 0; i < threads.size(); i++) {
115 threads[i]->join();
116 }
117 grpc_shutdown();
118 }
119
120 } // namespace
121
main(int argc,char ** argv)122 int main(int argc, char** argv) {
123 grpc::testing::TestEnvironment env(argc, argv);
124 ::testing::InitGoogleTest(&argc, argv);
125 auto result = RUN_ALL_TESTS();
126 return result;
127 }
128