1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // This test validates that the ProcessSingleton class properly makes sure 6 // that there is only one main browser process. 7 // 8 // It is currently compiled and run on Windows and Posix(non-Mac) platforms. 9 // Mac uses system services and ProcessSingletonMac is a noop. (Maybe it still 10 // makes sense to test that the system services are giving the behavior we 11 // want?) 12 13 #include <list> 14 15 #include "base/file_path.h" 16 #include "base/file_util.h" 17 #include "base/memory/ref_counted.h" 18 #include "base/memory/scoped_temp_dir.h" 19 #include "base/path_service.h" 20 #include "base/process_util.h" 21 #include "base/threading/thread.h" 22 #include "base/test/test_timeouts.h" 23 #include "base/synchronization/waitable_event.h" 24 #include "chrome/common/chrome_paths.h" 25 #include "chrome/common/chrome_constants.h" 26 #include "chrome/common/chrome_switches.h" 27 #include "chrome/test/test_launcher_utils.h" 28 #include "chrome/test/ui/ui_test.h" 29 #include "testing/gtest/include/gtest/gtest.h" 30 31 namespace { 32 33 // This is for the code that is to be ran in multiple threads at once, 34 // to stress a race condition on first process start. 35 // We use the thread safe ref counted base class so that we can use the 36 // NewRunnableMethod class to run the StartChrome methods in many threads. 37 class ChromeStarter : public base::RefCountedThreadSafe<ChromeStarter> { 38 public: 39 explicit ChromeStarter(int timeout_ms, const FilePath& user_data_dir) 40 : ready_event_(false /* manual */, false /* signaled */), 41 done_event_(false /* manual */, false /* signaled */), 42 process_handle_(base::kNullProcessHandle), 43 process_terminated_(false), 44 timeout_ms_(timeout_ms), 45 user_data_dir_(user_data_dir) { 46 } 47 48 // We must reset some data members since we reuse the same ChromeStarter 49 // object and start/stop it a few times. We must start fresh! :-) 50 void Reset() { 51 ready_event_.Reset(); 52 done_event_.Reset(); 53 if (process_handle_ != base::kNullProcessHandle) 54 base::CloseProcessHandle(process_handle_); 55 process_handle_ = base::kNullProcessHandle; 56 process_terminated_ = false; 57 } 58 59 void StartChrome(base::WaitableEvent* start_event, bool first_run) { 60 // TODO(mattm): maybe stuff should be refactored to use 61 // UITest::LaunchBrowserHelper somehow? 62 FilePath browser_directory; 63 PathService::Get(chrome::DIR_APP, &browser_directory); 64 CommandLine command_line(browser_directory.Append( 65 chrome::kBrowserProcessExecutablePath)); 66 67 command_line.AppendSwitchPath(switches::kUserDataDir, user_data_dir_); 68 69 if (first_run) 70 command_line.AppendSwitch(switches::kFirstRun); 71 else 72 command_line.AppendSwitch(switches::kNoFirstRun); 73 74 // Add the normal test-mode switches, except for the ones we're adding 75 // ourselves. 76 CommandLine standard_switches(CommandLine::NO_PROGRAM); 77 test_launcher_utils::PrepareBrowserCommandLineForTests(&standard_switches); 78 const CommandLine::SwitchMap& switch_map = standard_switches.GetSwitches(); 79 for (CommandLine::SwitchMap::const_iterator i = switch_map.begin(); 80 i != switch_map.end(); ++i) { 81 const std::string& switch_name = i->first; 82 if (switch_name == switches::kUserDataDir || 83 switch_name == switches::kFirstRun || 84 switch_name == switches::kNoFirstRun) 85 continue; 86 87 command_line.AppendSwitchNative(switch_name, i->second); 88 } 89 90 // Try to get all threads to launch the app at the same time. 91 // So let the test know we are ready. 92 ready_event_.Signal(); 93 // And then wait for the test to tell us to GO! 94 ASSERT_NE(static_cast<base::WaitableEvent*>(NULL), start_event); 95 ASSERT_TRUE(start_event->Wait()); 96 97 // Here we don't wait for the app to be terminated because one of the 98 // process will stay alive while the others will be restarted. If we would 99 // wait here, we would never get a handle to the main process... 100 base::LaunchApp(command_line, false /* wait */, 101 false /* hidden */, &process_handle_); 102 ASSERT_NE(base::kNullProcessHandle, process_handle_); 103 104 // We can wait on the handle here, we should get stuck on one and only 105 // one process. The test below will take care of killing that process 106 // to unstuck us once it confirms there is only one. 107 process_terminated_ = base::WaitForSingleProcess(process_handle_, 108 timeout_ms_); 109 // Let the test know we are done. 110 done_event_.Signal(); 111 } 112 113 // Public access to simplify the test code using them. 114 base::WaitableEvent ready_event_; 115 base::WaitableEvent done_event_; 116 base::ProcessHandle process_handle_; 117 bool process_terminated_; 118 119 private: 120 friend class base::RefCountedThreadSafe<ChromeStarter>; 121 122 ~ChromeStarter() { 123 if (process_handle_ != base::kNullProcessHandle) 124 base::CloseProcessHandle(process_handle_); 125 } 126 127 int timeout_ms_; 128 FilePath user_data_dir_; 129 130 DISALLOW_COPY_AND_ASSIGN(ChromeStarter); 131 }; 132 133 // Our test fixture that initializes and holds onto a few global vars. 134 class ProcessSingletonTest : public UITest { 135 public: 136 ProcessSingletonTest() 137 // We use a manual reset so that all threads wake up at once when signaled 138 // and thus we must manually reset it for each attempt. 139 : threads_waker_(true /* manual */, false /* signaled */) { 140 EXPECT_TRUE(temp_profile_dir_.CreateUniqueTempDir()); 141 } 142 143 void SetUp() { 144 // Start the threads and create the starters. 145 for (size_t i = 0; i < kNbThreads; ++i) { 146 chrome_starter_threads_[i].reset(new base::Thread("ChromeStarter")); 147 ASSERT_TRUE(chrome_starter_threads_[i]->Start()); 148 chrome_starters_[i] = new ChromeStarter( 149 TestTimeouts::action_max_timeout_ms(), temp_profile_dir_.path()); 150 } 151 } 152 153 void TearDown() { 154 // Stop the threads. 155 for (size_t i = 0; i < kNbThreads; ++i) 156 chrome_starter_threads_[i]->Stop(); 157 } 158 159 // This method is used to make sure we kill the main browser process after 160 // all of its child processes have successfully attached to it. This was added 161 // when we realized that if we just kill the parent process right away, we 162 // sometimes end up with dangling child processes. If we Sleep for a certain 163 // amount of time, we are OK... So we introduced this method to avoid a 164 // flaky wait. Instead, we kill all descendants of the main process after we 165 // killed it, relying on the fact that we can still get the parent id of a 166 // child process, even when the parent dies. 167 void KillProcessTree(base::ProcessHandle process_handle) { 168 class ProcessTreeFilter : public base::ProcessFilter { 169 public: 170 explicit ProcessTreeFilter(base::ProcessId parent_pid) { 171 ancestor_pids_.insert(parent_pid); 172 } 173 virtual bool Includes(const base::ProcessEntry & entry) const { 174 if (ancestor_pids_.find(entry.parent_pid()) != ancestor_pids_.end()) { 175 ancestor_pids_.insert(entry.pid()); 176 return true; 177 } else { 178 return false; 179 } 180 } 181 private: 182 mutable std::set<base::ProcessId> ancestor_pids_; 183 } process_tree_filter(base::GetProcId(process_handle)); 184 185 // Start by explicitly killing the main process we know about... 186 static const int kExitCode = 42; 187 EXPECT_TRUE(base::KillProcess(process_handle, kExitCode, true /* wait */)); 188 189 // Then loop until we can't find any of its descendant. 190 // But don't try more than kNbTries times... 191 static const int kNbTries = 10; 192 int num_tries = 0; 193 while (base::GetProcessCount(chrome::kBrowserProcessExecutablePath, 194 &process_tree_filter) > 0 && num_tries++ < kNbTries) { 195 base::KillProcesses(chrome::kBrowserProcessExecutablePath, 196 kExitCode, &process_tree_filter); 197 } 198 DLOG_IF(ERROR, num_tries >= kNbTries) << "Failed to kill all processes!"; 199 } 200 201 // Since this is a hard to reproduce problem, we make a few attempts. 202 // We stop the attempts at the first error, and when there are no errors, 203 // we don't time-out of any wait, so it executes quite fast anyway. 204 static const size_t kNbAttempts = 5; 205 206 // The idea is to start chrome from multiple threads all at once. 207 static const size_t kNbThreads = 5; 208 scoped_refptr<ChromeStarter> chrome_starters_[kNbThreads]; 209 scoped_ptr<base::Thread> chrome_starter_threads_[kNbThreads]; 210 211 // The event that will get all threads to wake up simultaneously and try 212 // to start a chrome process at the same time. 213 base::WaitableEvent threads_waker_; 214 215 // We don't want to use the default profile, but can't use UITest's since we 216 // don't use UITest::LaunchBrowser. 217 ScopedTempDir temp_profile_dir_; 218 }; 219 220 #if defined(OS_LINUX) && defined(TOOLKIT_VIEWS) 221 // http://crbug.com/58219 222 #define MAYBE_StartupRaceCondition FAILS_StartupRaceCondition 223 #else 224 #define MAYBE_StartupRaceCondition StartupRaceCondition 225 #endif 226 TEST_F(ProcessSingletonTest, MAYBE_StartupRaceCondition) { 227 // We use this to stop the attempts loop on the first failure. 228 bool failed = false; 229 for (size_t attempt = 0; attempt < kNbAttempts && !failed; ++attempt) { 230 SCOPED_TRACE(testing::Message() << "Attempt: " << attempt << "."); 231 // We use a single event to get all threads to do the AppLaunch at the same 232 // time... 233 threads_waker_.Reset(); 234 235 // Test both with and without the first-run dialog, since they exercise 236 // different paths. 237 #if defined(OS_POSIX) 238 // TODO(mattm): test first run dialog singleton handling on linux too. 239 // On posix if we test the first run dialog, GracefulShutdownHandler gets 240 // the TERM signal, but since the message loop isn't running during the gtk 241 // first run dialog, the ShutdownDetector never handles it, and KillProcess 242 // has to time out (60 sec!) and SIGKILL. 243 bool first_run = false; 244 #else 245 // Test for races in both regular start up and first run start up cases. 246 bool first_run = attempt % 2; 247 #endif 248 249 // Here we prime all the threads with a ChromeStarter that will wait for 250 // our signal to launch its chrome process. 251 for (size_t i = 0; i < kNbThreads; ++i) { 252 ASSERT_NE(static_cast<ChromeStarter*>(NULL), chrome_starters_[i].get()); 253 chrome_starters_[i]->Reset(); 254 255 ASSERT_TRUE(chrome_starter_threads_[i]->IsRunning()); 256 ASSERT_NE(static_cast<MessageLoop*>(NULL), 257 chrome_starter_threads_[i]->message_loop()); 258 259 chrome_starter_threads_[i]->message_loop()->PostTask( 260 FROM_HERE, NewRunnableMethod(chrome_starters_[i].get(), 261 &ChromeStarter::StartChrome, 262 &threads_waker_, 263 first_run)); 264 } 265 266 // Wait for all the starters to be ready. 267 // We could replace this loop if we ever implement a WaitAll(). 268 for (size_t i = 0; i < kNbThreads; ++i) { 269 SCOPED_TRACE(testing::Message() << "Waiting on thread: " << i << "."); 270 ASSERT_TRUE(chrome_starters_[i]->ready_event_.Wait()); 271 } 272 // GO! 273 threads_waker_.Signal(); 274 275 // As we wait for all threads to signal that they are done, we remove their 276 // index from this vector so that we get left with only the index of 277 // the thread that started the main process. 278 std::vector<size_t> pending_starters(kNbThreads); 279 for (size_t i = 0; i < kNbThreads; ++i) 280 pending_starters[i] = i; 281 282 // We use a local array of starter's done events we must wait on... 283 // These are collected from the starters that we have not yet been removed 284 // from the pending_starters vector. 285 base::WaitableEvent* starters_done_events[kNbThreads]; 286 // At the end, "There can be only one" main browser process alive. 287 while (pending_starters.size() > 1) { 288 SCOPED_TRACE(testing::Message() << pending_starters.size() << 289 " starters left."); 290 for (size_t i = 0; i < pending_starters.size(); ++i) { 291 starters_done_events[i] = 292 &chrome_starters_[pending_starters[i]]->done_event_; 293 } 294 size_t done_index = base::WaitableEvent::WaitMany( 295 starters_done_events, pending_starters.size()); 296 size_t starter_index = pending_starters[done_index]; 297 // If the starter is done but has not marked itself as terminated, 298 // it is because it timed out of its WaitForSingleProcess(). Only the 299 // last one standing should be left waiting... So we failed... 300 EXPECT_TRUE(chrome_starters_[starter_index]->process_terminated_ || 301 failed) << "There is more than one main process."; 302 if (!chrome_starters_[starter_index]->process_terminated_) { 303 // This will stop the "for kNbAttempts" loop. 304 failed = true; 305 // But we let the last loop turn finish so that we can properly 306 // kill all remaining processes. Starting with this one... 307 if (chrome_starters_[starter_index]->process_handle_ != 308 base::kNullProcessHandle) { 309 KillProcessTree(chrome_starters_[starter_index]->process_handle_); 310 } 311 } 312 pending_starters.erase(pending_starters.begin() + done_index); 313 } 314 315 // "There can be only one!" :-) 316 ASSERT_EQ(static_cast<size_t>(1), pending_starters.size()); 317 size_t last_index = pending_starters.front(); 318 pending_starters.empty(); 319 if (chrome_starters_[last_index]->process_handle_ != 320 base::kNullProcessHandle) { 321 KillProcessTree(chrome_starters_[last_index]->process_handle_); 322 chrome_starters_[last_index]->done_event_.Wait(); 323 } 324 } 325 } 326 327 } // namespace 328
