xref: /llvm-project/lldb/unittests/Host/MainLoopTest.cpp (revision 65596cede8a4bcb8532b37702aa2b42270d4315c)
1 //===-- MainLoopTest.cpp --------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "lldb/Host/MainLoop.h"
10 #include "TestingSupport/SubsystemRAII.h"
11 #include "lldb/Host/ConnectionFileDescriptor.h"
12 #include "lldb/Host/PseudoTerminal.h"
13 #include "lldb/Host/common/TCPSocket.h"
14 #include "llvm/Testing/Support/Error.h"
15 #include "gtest/gtest.h"
16 #include <future>
17 
18 using namespace lldb_private;
19 
20 namespace {
21 class MainLoopTest : public testing::Test {
22 public:
23   SubsystemRAII<Socket> subsystems;
24 
25   void SetUp() override {
26     bool child_processes_inherit = false;
27     Status error;
28     std::unique_ptr<TCPSocket> listen_socket_up(
29         new TCPSocket(true, child_processes_inherit));
30     ASSERT_TRUE(error.Success());
31     error = listen_socket_up->Listen("localhost:0", 5);
32     ASSERT_TRUE(error.Success());
33 
34     Socket *accept_socket;
35     std::unique_ptr<TCPSocket> connect_socket_up(
36         new TCPSocket(true, child_processes_inherit));
37     error = connect_socket_up->Connect(
38         llvm::formatv("localhost:{0}", listen_socket_up->GetLocalPortNumber())
39             .str());
40     ASSERT_TRUE(error.Success());
41     ASSERT_TRUE(listen_socket_up->Accept(accept_socket).Success());
42 
43     callback_count = 0;
44     socketpair[0] = std::move(connect_socket_up);
45     socketpair[1].reset(accept_socket);
46   }
47 
48   void TearDown() override {
49     socketpair[0].reset();
50     socketpair[1].reset();
51   }
52 
53 protected:
54   MainLoop::Callback make_callback() {
55     return [&](MainLoopBase &loop) {
56       ++callback_count;
57       loop.RequestTermination();
58     };
59   }
60   std::shared_ptr<Socket> socketpair[2];
61   unsigned callback_count;
62 };
63 } // namespace
64 
65 TEST_F(MainLoopTest, ReadObject) {
66   char X = 'X';
67   size_t len = sizeof(X);
68   ASSERT_TRUE(socketpair[0]->Write(&X, len).Success());
69 
70   MainLoop loop;
71 
72   Status error;
73   auto handle = loop.RegisterReadObject(socketpair[1], make_callback(), error);
74   ASSERT_TRUE(error.Success());
75   ASSERT_TRUE(handle);
76   ASSERT_TRUE(loop.Run().Success());
77   ASSERT_EQ(1u, callback_count);
78 }
79 
80 TEST_F(MainLoopTest, TerminatesImmediately) {
81   char X = 'X';
82   size_t len = sizeof(X);
83   ASSERT_TRUE(socketpair[0]->Write(&X, len).Success());
84   ASSERT_TRUE(socketpair[1]->Write(&X, len).Success());
85 
86   MainLoop loop;
87   Status error;
88   auto handle0 = loop.RegisterReadObject(socketpair[0], make_callback(), error);
89   ASSERT_TRUE(error.Success());
90   auto handle1 = loop.RegisterReadObject(socketpair[1], make_callback(), error);
91   ASSERT_TRUE(error.Success());
92 
93   ASSERT_TRUE(loop.Run().Success());
94   ASSERT_EQ(1u, callback_count);
95 }
96 
97 TEST_F(MainLoopTest, PendingCallback) {
98   char X = 'X';
99   size_t len = sizeof(X);
100   ASSERT_TRUE(socketpair[0]->Write(&X, len).Success());
101 
102   MainLoop loop;
103   Status error;
104   auto handle = loop.RegisterReadObject(
105       socketpair[1],
106       [&](MainLoopBase &loop) {
107         // Both callbacks should be called before the loop terminates.
108         loop.AddPendingCallback(make_callback());
109         loop.AddPendingCallback(make_callback());
110         loop.RequestTermination();
111       },
112       error);
113   ASSERT_TRUE(error.Success());
114   ASSERT_TRUE(handle);
115   ASSERT_TRUE(loop.Run().Success());
116   ASSERT_EQ(2u, callback_count);
117 }
118 
119 TEST_F(MainLoopTest, PendingCallbackCalledOnlyOnce) {
120   char X = 'X';
121   size_t len = sizeof(X);
122   ASSERT_TRUE(socketpair[0]->Write(&X, len).Success());
123 
124   MainLoop loop;
125   Status error;
126   auto handle = loop.RegisterReadObject(
127       socketpair[1],
128       [&](MainLoopBase &loop) {
129         // Add one pending callback on the first iteration.
130         if (callback_count == 0) {
131           loop.AddPendingCallback([&](MainLoopBase &loop) {
132             callback_count++;
133           });
134         }
135         // Terminate the loop on second iteration.
136         if (callback_count++ >= 1)
137           loop.RequestTermination();
138       },
139       error);
140   ASSERT_TRUE(error.Success());
141   ASSERT_TRUE(handle);
142   ASSERT_TRUE(loop.Run().Success());
143   // 2 iterations of read callback + 1 call of pending callback.
144   ASSERT_EQ(3u, callback_count);
145 }
146 
147 TEST_F(MainLoopTest, PendingCallbackTrigger) {
148   MainLoop loop;
149   std::promise<void> add_callback2;
150   bool callback1_called = false;
151   loop.AddPendingCallback([&](MainLoopBase &loop) {
152     callback1_called = true;
153     add_callback2.set_value();
154   });
155   Status error;
156   auto socket_handle = loop.RegisterReadObject(
157       socketpair[1], [](MainLoopBase &) {}, error);
158   ASSERT_TRUE(socket_handle);
159   ASSERT_THAT_ERROR(error.ToError(), llvm::Succeeded());
160   bool callback2_called = false;
161   std::thread callback2_adder([&]() {
162     add_callback2.get_future().get();
163     loop.AddPendingCallback([&](MainLoopBase &loop) {
164       callback2_called = true;
165       loop.RequestTermination();
166     });
167   });
168   ASSERT_THAT_ERROR(loop.Run().ToError(), llvm::Succeeded());
169   callback2_adder.join();
170   ASSERT_TRUE(callback1_called);
171   ASSERT_TRUE(callback2_called);
172 }
173 
174 #ifdef LLVM_ON_UNIX
175 TEST_F(MainLoopTest, DetectsEOF) {
176 
177   PseudoTerminal term;
178   ASSERT_THAT_ERROR(term.OpenFirstAvailablePrimary(O_RDWR), llvm::Succeeded());
179   ASSERT_THAT_ERROR(term.OpenSecondary(O_RDWR | O_NOCTTY), llvm::Succeeded());
180   auto conn = std::make_unique<ConnectionFileDescriptor>(
181       term.ReleasePrimaryFileDescriptor(), true);
182 
183   Status error;
184   MainLoop loop;
185   auto handle =
186       loop.RegisterReadObject(conn->GetReadObject(), make_callback(), error);
187   ASSERT_TRUE(error.Success());
188   term.CloseSecondaryFileDescriptor();
189 
190   ASSERT_TRUE(loop.Run().Success());
191   ASSERT_EQ(1u, callback_count);
192 }
193 
194 TEST_F(MainLoopTest, Signal) {
195   MainLoop loop;
196   Status error;
197 
198   auto handle = loop.RegisterSignal(SIGUSR1, make_callback(), error);
199   ASSERT_TRUE(error.Success());
200   kill(getpid(), SIGUSR1);
201   ASSERT_TRUE(loop.Run().Success());
202   ASSERT_EQ(1u, callback_count);
203 }
204 
205 // Test that a signal which is not monitored by the MainLoop does not
206 // cause a premature exit.
207 TEST_F(MainLoopTest, UnmonitoredSignal) {
208   MainLoop loop;
209   Status error;
210   struct sigaction sa;
211   sa.sa_sigaction = [](int, siginfo_t *, void *) { };
212   sa.sa_flags = SA_SIGINFO; // important: no SA_RESTART
213   sigemptyset(&sa.sa_mask);
214   ASSERT_EQ(0, sigaction(SIGUSR2, &sa, nullptr));
215 
216   auto handle = loop.RegisterSignal(SIGUSR1, make_callback(), error);
217   ASSERT_TRUE(error.Success());
218   kill(getpid(), SIGUSR2);
219   kill(getpid(), SIGUSR1);
220   ASSERT_TRUE(loop.Run().Success());
221   ASSERT_EQ(1u, callback_count);
222 }
223 
224 // Test that two callbacks can be registered for the same signal
225 // and unregistered independently.
226 TEST_F(MainLoopTest, TwoSignalCallbacks) {
227   MainLoop loop;
228   Status error;
229   unsigned callback2_count = 0;
230   unsigned callback3_count = 0;
231 
232   auto handle = loop.RegisterSignal(SIGUSR1, make_callback(), error);
233   ASSERT_TRUE(error.Success());
234 
235   {
236     // Run a single iteration with two callbacks enabled.
237     auto handle2 = loop.RegisterSignal(
238         SIGUSR1, [&](MainLoopBase &loop) { ++callback2_count; }, error);
239     ASSERT_TRUE(error.Success());
240 
241     kill(getpid(), SIGUSR1);
242     ASSERT_TRUE(loop.Run().Success());
243     ASSERT_EQ(1u, callback_count);
244     ASSERT_EQ(1u, callback2_count);
245     ASSERT_EQ(0u, callback3_count);
246   }
247 
248   {
249     // Make sure that remove + add new works.
250     auto handle3 = loop.RegisterSignal(
251         SIGUSR1, [&](MainLoopBase &loop) { ++callback3_count; }, error);
252     ASSERT_TRUE(error.Success());
253 
254     kill(getpid(), SIGUSR1);
255     ASSERT_TRUE(loop.Run().Success());
256     ASSERT_EQ(2u, callback_count);
257     ASSERT_EQ(1u, callback2_count);
258     ASSERT_EQ(1u, callback3_count);
259   }
260 
261   // Both extra callbacks should be unregistered now.
262   kill(getpid(), SIGUSR1);
263   ASSERT_TRUE(loop.Run().Success());
264   ASSERT_EQ(3u, callback_count);
265   ASSERT_EQ(1u, callback2_count);
266   ASSERT_EQ(1u, callback3_count);
267 }
268 #endif
269