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| 1 // Copyright (c) 2012 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 #include "base/message_loop/message_pump_win.h" | |
| 6 | |
| 7 #include <limits> | |
| 8 #include <math.h> | |
| 9 | |
| 10 #include "base/message_loop/message_loop.h" | |
| 11 #include "base/metrics/histogram.h" | |
| 12 #include "base/process/memory.h" | |
| 13 #include "base/profiler/scoped_tracker.h" | |
| 14 #include "base/strings/stringprintf.h" | |
| 15 #include "base/trace_event/trace_event.h" | |
| 16 #include "base/win/wrapped_window_proc.h" | |
| 17 | |
| 18 namespace base { | |
| 19 | |
| 20 namespace { | |
| 21 | |
| 22 enum MessageLoopProblems { | |
| 23 MESSAGE_POST_ERROR, | |
| 24 COMPLETION_POST_ERROR, | |
| 25 SET_TIMER_ERROR, | |
| 26 MESSAGE_LOOP_PROBLEM_MAX, | |
| 27 }; | |
| 28 | |
| 29 } // namespace | |
| 30 | |
| 31 static const wchar_t kWndClassFormat[] = L"Chrome_MessagePumpWindow_%p"; | |
| 32 | |
| 33 // Message sent to get an additional time slice for pumping (processing) another | |
| 34 // task (a series of such messages creates a continuous task pump). | |
| 35 static const int kMsgHaveWork = WM_USER + 1; | |
| 36 | |
| 37 //----------------------------------------------------------------------------- | |
| 38 // MessagePumpWin public: | |
| 39 | |
| 40 void MessagePumpWin::RunWithDispatcher( | |
| 41 Delegate* delegate, MessagePumpDispatcher* dispatcher) { | |
| 42 RunState s; | |
| 43 s.delegate = delegate; | |
| 44 s.dispatcher = dispatcher; | |
| 45 s.should_quit = false; | |
| 46 s.run_depth = state_ ? state_->run_depth + 1 : 1; | |
| 47 | |
| 48 RunState* previous_state = state_; | |
| 49 state_ = &s; | |
| 50 | |
| 51 DoRunLoop(); | |
| 52 | |
| 53 state_ = previous_state; | |
| 54 } | |
| 55 | |
| 56 void MessagePumpWin::Run(Delegate* delegate) { | |
| 57 RunWithDispatcher(delegate, NULL); | |
| 58 } | |
| 59 | |
| 60 void MessagePumpWin::Quit() { | |
| 61 DCHECK(state_); | |
| 62 state_->should_quit = true; | |
| 63 } | |
| 64 | |
| 65 //----------------------------------------------------------------------------- | |
| 66 // MessagePumpWin protected: | |
| 67 | |
| 68 int MessagePumpWin::GetCurrentDelay() const { | |
| 69 if (delayed_work_time_.is_null()) | |
| 70 return -1; | |
| 71 | |
| 72 // Be careful here. TimeDelta has a precision of microseconds, but we want a | |
| 73 // value in milliseconds. If there are 5.5ms left, should the delay be 5 or | |
| 74 // 6? It should be 6 to avoid executing delayed work too early. | |
| 75 double timeout = | |
| 76 ceil((delayed_work_time_ - TimeTicks::Now()).InMillisecondsF()); | |
| 77 | |
| 78 // Range check the |timeout| while converting to an integer. If the |timeout| | |
| 79 // is negative, then we need to run delayed work soon. If the |timeout| is | |
| 80 // "overflowingly" large, that means a delayed task was posted with a | |
| 81 // super-long delay. | |
| 82 return timeout < 0 ? 0 : | |
| 83 (timeout > std::numeric_limits<int>::max() ? | |
| 84 std::numeric_limits<int>::max() : static_cast<int>(timeout)); | |
| 85 } | |
| 86 | |
| 87 //----------------------------------------------------------------------------- | |
| 88 // MessagePumpForUI public: | |
| 89 | |
| 90 MessagePumpForUI::MessagePumpForUI() | |
| 91 : atom_(0) { | |
| 92 InitMessageWnd(); | |
| 93 } | |
| 94 | |
| 95 MessagePumpForUI::~MessagePumpForUI() { | |
| 96 DestroyWindow(message_hwnd_); | |
| 97 UnregisterClass(MAKEINTATOM(atom_), | |
| 98 GetModuleFromAddress(&WndProcThunk)); | |
| 99 } | |
| 100 | |
| 101 void MessagePumpForUI::ScheduleWork() { | |
| 102 if (InterlockedExchange(&have_work_, 1)) | |
| 103 return; // Someone else continued the pumping. | |
| 104 | |
| 105 // Make sure the MessagePump does some work for us. | |
| 106 BOOL ret = PostMessage(message_hwnd_, kMsgHaveWork, | |
| 107 reinterpret_cast<WPARAM>(this), 0); | |
| 108 if (ret) | |
| 109 return; // There was room in the Window Message queue. | |
| 110 | |
| 111 // We have failed to insert a have-work message, so there is a chance that we | |
| 112 // will starve tasks/timers while sitting in a nested message loop. Nested | |
| 113 // loops only look at Windows Message queues, and don't look at *our* task | |
| 114 // queues, etc., so we might not get a time slice in such. :-( | |
| 115 // We could abort here, but the fear is that this failure mode is plausibly | |
| 116 // common (queue is full, of about 2000 messages), so we'll do a near-graceful | |
| 117 // recovery. Nested loops are pretty transient (we think), so this will | |
| 118 // probably be recoverable. | |
| 119 InterlockedExchange(&have_work_, 0); // Clarify that we didn't really insert. | |
| 120 UMA_HISTOGRAM_ENUMERATION("Chrome.MessageLoopProblem", MESSAGE_POST_ERROR, | |
| 121 MESSAGE_LOOP_PROBLEM_MAX); | |
| 122 } | |
| 123 | |
| 124 void MessagePumpForUI::ScheduleDelayedWork(const TimeTicks& delayed_work_time) { | |
| 125 delayed_work_time_ = delayed_work_time; | |
| 126 RescheduleTimer(); | |
| 127 } | |
| 128 | |
| 129 //----------------------------------------------------------------------------- | |
| 130 // MessagePumpForUI private: | |
| 131 | |
| 132 // static | |
| 133 LRESULT CALLBACK MessagePumpForUI::WndProcThunk( | |
| 134 HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam) { | |
| 135 // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed. | |
| 136 tracked_objects::ScopedTracker tracking_profile1( | |
| 137 FROM_HERE_WITH_EXPLICIT_FUNCTION( | |
| 138 "440919 MessagePumpForUI::WndProcThunk1")); | |
| 139 | |
| 140 switch (message) { | |
| 141 case kMsgHaveWork: | |
| 142 reinterpret_cast<MessagePumpForUI*>(wparam)->HandleWorkMessage(); | |
| 143 break; | |
| 144 case WM_TIMER: | |
| 145 reinterpret_cast<MessagePumpForUI*>(wparam)->HandleTimerMessage(); | |
| 146 break; | |
| 147 } | |
| 148 | |
| 149 // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed. | |
| 150 tracked_objects::ScopedTracker tracking_profile2( | |
| 151 FROM_HERE_WITH_EXPLICIT_FUNCTION( | |
| 152 "440919 MessagePumpForUI::WndProcThunk2")); | |
| 153 | |
| 154 return DefWindowProc(hwnd, message, wparam, lparam); | |
| 155 } | |
| 156 | |
| 157 void MessagePumpForUI::DoRunLoop() { | |
| 158 // IF this was just a simple PeekMessage() loop (servicing all possible work | |
| 159 // queues), then Windows would try to achieve the following order according | |
| 160 // to MSDN documentation about PeekMessage with no filter): | |
| 161 // * Sent messages | |
| 162 // * Posted messages | |
| 163 // * Sent messages (again) | |
| 164 // * WM_PAINT messages | |
| 165 // * WM_TIMER messages | |
| 166 // | |
| 167 // Summary: none of the above classes is starved, and sent messages has twice | |
| 168 // the chance of being processed (i.e., reduced service time). | |
| 169 | |
| 170 for (;;) { | |
| 171 // If we do any work, we may create more messages etc., and more work may | |
| 172 // possibly be waiting in another task group. When we (for example) | |
| 173 // ProcessNextWindowsMessage(), there is a good chance there are still more | |
| 174 // messages waiting. On the other hand, when any of these methods return | |
| 175 // having done no work, then it is pretty unlikely that calling them again | |
| 176 // quickly will find any work to do. Finally, if they all say they had no | |
| 177 // work, then it is a good time to consider sleeping (waiting) for more | |
| 178 // work. | |
| 179 | |
| 180 bool more_work_is_plausible = ProcessNextWindowsMessage(); | |
| 181 if (state_->should_quit) | |
| 182 break; | |
| 183 | |
| 184 more_work_is_plausible |= state_->delegate->DoWork(); | |
| 185 if (state_->should_quit) | |
| 186 break; | |
| 187 | |
| 188 more_work_is_plausible |= | |
| 189 state_->delegate->DoDelayedWork(&delayed_work_time_); | |
| 190 // If we did not process any delayed work, then we can assume that our | |
| 191 // existing WM_TIMER if any will fire when delayed work should run. We | |
| 192 // don't want to disturb that timer if it is already in flight. However, | |
| 193 // if we did do all remaining delayed work, then lets kill the WM_TIMER. | |
| 194 if (more_work_is_plausible && delayed_work_time_.is_null()) | |
| 195 KillTimer(message_hwnd_, reinterpret_cast<UINT_PTR>(this)); | |
| 196 if (state_->should_quit) | |
| 197 break; | |
| 198 | |
| 199 if (more_work_is_plausible) | |
| 200 continue; | |
| 201 | |
| 202 more_work_is_plausible = state_->delegate->DoIdleWork(); | |
| 203 if (state_->should_quit) | |
| 204 break; | |
| 205 | |
| 206 if (more_work_is_plausible) | |
| 207 continue; | |
| 208 | |
| 209 WaitForWork(); // Wait (sleep) until we have work to do again. | |
| 210 } | |
| 211 } | |
| 212 | |
| 213 void MessagePumpForUI::InitMessageWnd() { | |
| 214 // Generate a unique window class name. | |
| 215 string16 class_name = StringPrintf(kWndClassFormat, this); | |
| 216 | |
| 217 HINSTANCE instance = GetModuleFromAddress(&WndProcThunk); | |
| 218 WNDCLASSEX wc = {0}; | |
| 219 wc.cbSize = sizeof(wc); | |
| 220 wc.lpfnWndProc = base::win::WrappedWindowProc<WndProcThunk>; | |
| 221 wc.hInstance = instance; | |
| 222 wc.lpszClassName = class_name.c_str(); | |
| 223 atom_ = RegisterClassEx(&wc); | |
| 224 DCHECK(atom_); | |
| 225 | |
| 226 message_hwnd_ = CreateWindow(MAKEINTATOM(atom_), 0, 0, 0, 0, 0, 0, | |
| 227 HWND_MESSAGE, 0, instance, 0); | |
| 228 DCHECK(message_hwnd_); | |
| 229 } | |
| 230 | |
| 231 void MessagePumpForUI::WaitForWork() { | |
| 232 // Wait until a message is available, up to the time needed by the timer | |
| 233 // manager to fire the next set of timers. | |
| 234 int delay = GetCurrentDelay(); | |
| 235 if (delay < 0) // Negative value means no timers waiting. | |
| 236 delay = INFINITE; | |
| 237 | |
| 238 DWORD result; | |
| 239 result = MsgWaitForMultipleObjectsEx(0, NULL, delay, QS_ALLINPUT, | |
| 240 MWMO_INPUTAVAILABLE); | |
| 241 | |
| 242 if (WAIT_OBJECT_0 == result) { | |
| 243 // A WM_* message is available. | |
| 244 // If a parent child relationship exists between windows across threads | |
| 245 // then their thread inputs are implicitly attached. | |
| 246 // This causes the MsgWaitForMultipleObjectsEx API to return indicating | |
| 247 // that messages are ready for processing (Specifically, mouse messages | |
| 248 // intended for the child window may appear if the child window has | |
| 249 // capture). | |
| 250 // The subsequent PeekMessages call may fail to return any messages thus | |
| 251 // causing us to enter a tight loop at times. | |
| 252 // The WaitMessage call below is a workaround to give the child window | |
| 253 // some time to process its input messages. | |
| 254 MSG msg = {0}; | |
| 255 DWORD queue_status = GetQueueStatus(QS_MOUSE); | |
| 256 if (HIWORD(queue_status) & QS_MOUSE && | |
| 257 !PeekMessage(&msg, NULL, WM_MOUSEFIRST, WM_MOUSELAST, PM_NOREMOVE)) { | |
| 258 WaitMessage(); | |
| 259 } | |
| 260 return; | |
| 261 } | |
| 262 | |
| 263 DCHECK_NE(WAIT_FAILED, result) << GetLastError(); | |
| 264 } | |
| 265 | |
| 266 void MessagePumpForUI::HandleWorkMessage() { | |
| 267 // If we are being called outside of the context of Run, then don't try to do | |
| 268 // any work. This could correspond to a MessageBox call or something of that | |
| 269 // sort. | |
| 270 if (!state_) { | |
| 271 // Since we handled a kMsgHaveWork message, we must still update this flag. | |
| 272 InterlockedExchange(&have_work_, 0); | |
| 273 return; | |
| 274 } | |
| 275 | |
| 276 // Let whatever would have run had we not been putting messages in the queue | |
| 277 // run now. This is an attempt to make our dummy message not starve other | |
| 278 // messages that may be in the Windows message queue. | |
| 279 ProcessPumpReplacementMessage(); | |
| 280 | |
| 281 // Now give the delegate a chance to do some work. He'll let us know if he | |
| 282 // needs to do more work. | |
| 283 if (state_->delegate->DoWork()) | |
| 284 ScheduleWork(); | |
| 285 state_->delegate->DoDelayedWork(&delayed_work_time_); | |
| 286 RescheduleTimer(); | |
| 287 } | |
| 288 | |
| 289 void MessagePumpForUI::HandleTimerMessage() { | |
| 290 KillTimer(message_hwnd_, reinterpret_cast<UINT_PTR>(this)); | |
| 291 | |
| 292 // If we are being called outside of the context of Run, then don't do | |
| 293 // anything. This could correspond to a MessageBox call or something of | |
| 294 // that sort. | |
| 295 if (!state_) | |
| 296 return; | |
| 297 | |
| 298 state_->delegate->DoDelayedWork(&delayed_work_time_); | |
| 299 RescheduleTimer(); | |
| 300 } | |
| 301 | |
| 302 void MessagePumpForUI::RescheduleTimer() { | |
| 303 if (delayed_work_time_.is_null()) | |
| 304 return; | |
| 305 // | |
| 306 // We would *like* to provide high resolution timers. Windows timers using | |
| 307 // SetTimer() have a 10ms granularity. We have to use WM_TIMER as a wakeup | |
| 308 // mechanism because the application can enter modal windows loops where it | |
| 309 // is not running our MessageLoop; the only way to have our timers fire in | |
| 310 // these cases is to post messages there. | |
| 311 // | |
| 312 // To provide sub-10ms timers, we process timers directly from our run loop. | |
| 313 // For the common case, timers will be processed there as the run loop does | |
| 314 // its normal work. However, we *also* set the system timer so that WM_TIMER | |
| 315 // events fire. This mops up the case of timers not being able to work in | |
| 316 // modal message loops. It is possible for the SetTimer to pop and have no | |
| 317 // pending timers, because they could have already been processed by the | |
| 318 // run loop itself. | |
| 319 // | |
| 320 // We use a single SetTimer corresponding to the timer that will expire | |
| 321 // soonest. As new timers are created and destroyed, we update SetTimer. | |
| 322 // Getting a spurrious SetTimer event firing is benign, as we'll just be | |
| 323 // processing an empty timer queue. | |
| 324 // | |
| 325 int delay_msec = GetCurrentDelay(); | |
| 326 DCHECK_GE(delay_msec, 0); | |
| 327 if (delay_msec == 0) { | |
| 328 ScheduleWork(); | |
| 329 } else { | |
| 330 if (delay_msec < USER_TIMER_MINIMUM) | |
| 331 delay_msec = USER_TIMER_MINIMUM; | |
| 332 | |
| 333 // Create a WM_TIMER event that will wake us up to check for any pending | |
| 334 // timers (in case we are running within a nested, external sub-pump). | |
| 335 BOOL ret = SetTimer(message_hwnd_, reinterpret_cast<UINT_PTR>(this), | |
| 336 delay_msec, NULL); | |
| 337 if (ret) | |
| 338 return; | |
| 339 // If we can't set timers, we are in big trouble... but cross our fingers | |
| 340 // for now. | |
| 341 // TODO(jar): If we don't see this error, use a CHECK() here instead. | |
| 342 UMA_HISTOGRAM_ENUMERATION("Chrome.MessageLoopProblem", SET_TIMER_ERROR, | |
| 343 MESSAGE_LOOP_PROBLEM_MAX); | |
| 344 } | |
| 345 } | |
| 346 | |
| 347 bool MessagePumpForUI::ProcessNextWindowsMessage() { | |
| 348 // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed. | |
| 349 tracked_objects::ScopedTracker tracking_profile1( | |
| 350 FROM_HERE_WITH_EXPLICIT_FUNCTION( | |
| 351 "440919 MessagePumpForUI::ProcessNextWindowsMessage1")); | |
| 352 | |
| 353 // If there are sent messages in the queue then PeekMessage internally | |
| 354 // dispatches the message and returns false. We return true in this | |
| 355 // case to ensure that the message loop peeks again instead of calling | |
| 356 // MsgWaitForMultipleObjectsEx again. | |
| 357 bool sent_messages_in_queue = false; | |
| 358 DWORD queue_status = GetQueueStatus(QS_SENDMESSAGE); | |
| 359 if (HIWORD(queue_status) & QS_SENDMESSAGE) | |
| 360 sent_messages_in_queue = true; | |
| 361 | |
| 362 // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed. | |
| 363 tracked_objects::ScopedTracker tracking_profile2( | |
| 364 FROM_HERE_WITH_EXPLICIT_FUNCTION( | |
| 365 "440919 MessagePumpForUI::ProcessNextWindowsMessage2")); | |
| 366 | |
| 367 MSG msg; | |
| 368 if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE) != FALSE) | |
| 369 return ProcessMessageHelper(msg); | |
| 370 | |
| 371 return sent_messages_in_queue; | |
| 372 } | |
| 373 | |
| 374 bool MessagePumpForUI::ProcessMessageHelper(const MSG& msg) { | |
| 375 TRACE_EVENT1("base", "MessagePumpForUI::ProcessMessageHelper", | |
| 376 "message", msg.message); | |
| 377 if (WM_QUIT == msg.message) { | |
| 378 // Repost the QUIT message so that it will be retrieved by the primary | |
| 379 // GetMessage() loop. | |
| 380 state_->should_quit = true; | |
| 381 PostQuitMessage(static_cast<int>(msg.wParam)); | |
| 382 return false; | |
| 383 } | |
| 384 | |
| 385 // While running our main message pump, we discard kMsgHaveWork messages. | |
| 386 if (msg.message == kMsgHaveWork && msg.hwnd == message_hwnd_) | |
| 387 return ProcessPumpReplacementMessage(); | |
| 388 | |
| 389 if (CallMsgFilter(const_cast<MSG*>(&msg), kMessageFilterCode)) | |
| 390 return true; | |
| 391 | |
| 392 uint32_t action = MessagePumpDispatcher::POST_DISPATCH_PERFORM_DEFAULT; | |
| 393 if (state_->dispatcher) { | |
| 394 // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed. | |
| 395 tracked_objects::ScopedTracker tracking_profile4( | |
| 396 FROM_HERE_WITH_EXPLICIT_FUNCTION( | |
| 397 "440919 MessagePumpForUI::ProcessMessageHelper4")); | |
| 398 | |
| 399 action = state_->dispatcher->Dispatch(msg); | |
| 400 } | |
| 401 if (action & MessagePumpDispatcher::POST_DISPATCH_QUIT_LOOP) | |
| 402 state_->should_quit = true; | |
| 403 if (action & MessagePumpDispatcher::POST_DISPATCH_PERFORM_DEFAULT) { | |
| 404 TranslateMessage(&msg); | |
| 405 DispatchMessage(&msg); | |
| 406 } | |
| 407 | |
| 408 return true; | |
| 409 } | |
| 410 | |
| 411 bool MessagePumpForUI::ProcessPumpReplacementMessage() { | |
| 412 // When we encounter a kMsgHaveWork message, this method is called to peek | |
| 413 // and process a replacement message, such as a WM_PAINT or WM_TIMER. The | |
| 414 // goal is to make the kMsgHaveWork as non-intrusive as possible, even though | |
| 415 // a continuous stream of such messages are posted. This method carefully | |
| 416 // peeks a message while there is no chance for a kMsgHaveWork to be pending, | |
| 417 // then resets the have_work_ flag (allowing a replacement kMsgHaveWork to | |
| 418 // possibly be posted), and finally dispatches that peeked replacement. Note | |
| 419 // that the re-post of kMsgHaveWork may be asynchronous to this thread!! | |
| 420 | |
| 421 bool have_message = false; | |
| 422 MSG msg; | |
| 423 // We should not process all window messages if we are in the context of an | |
| 424 // OS modal loop, i.e. in the context of a windows API call like MessageBox. | |
| 425 // This is to ensure that these messages are peeked out by the OS modal loop. | |
| 426 if (MessageLoop::current()->os_modal_loop()) { | |
| 427 // We only peek out WM_PAINT and WM_TIMER here for reasons mentioned above. | |
| 428 have_message = PeekMessage(&msg, NULL, WM_PAINT, WM_PAINT, PM_REMOVE) || | |
| 429 PeekMessage(&msg, NULL, WM_TIMER, WM_TIMER, PM_REMOVE); | |
| 430 } else { | |
| 431 have_message = PeekMessage(&msg, NULL, 0, 0, PM_REMOVE) != FALSE; | |
| 432 } | |
| 433 | |
| 434 DCHECK(!have_message || kMsgHaveWork != msg.message || | |
| 435 msg.hwnd != message_hwnd_); | |
| 436 | |
| 437 // Since we discarded a kMsgHaveWork message, we must update the flag. | |
| 438 int old_have_work = InterlockedExchange(&have_work_, 0); | |
| 439 DCHECK(old_have_work); | |
| 440 | |
| 441 // We don't need a special time slice if we didn't have_message to process. | |
| 442 if (!have_message) | |
| 443 return false; | |
| 444 | |
| 445 // Guarantee we'll get another time slice in the case where we go into native | |
| 446 // windows code. This ScheduleWork() may hurt performance a tiny bit when | |
| 447 // tasks appear very infrequently, but when the event queue is busy, the | |
| 448 // kMsgHaveWork events get (percentage wise) rarer and rarer. | |
| 449 ScheduleWork(); | |
| 450 return ProcessMessageHelper(msg); | |
| 451 } | |
| 452 | |
| 453 //----------------------------------------------------------------------------- | |
| 454 // MessagePumpForIO public: | |
| 455 | |
| 456 MessagePumpForIO::MessagePumpForIO() { | |
| 457 port_.Set(CreateIoCompletionPort(INVALID_HANDLE_VALUE, NULL, NULL, 1)); | |
| 458 DCHECK(port_.IsValid()); | |
| 459 } | |
| 460 | |
| 461 MessagePumpForIO::~MessagePumpForIO() { | |
| 462 } | |
| 463 | |
| 464 void MessagePumpForIO::ScheduleWork() { | |
| 465 if (InterlockedExchange(&have_work_, 1)) | |
| 466 return; // Someone else continued the pumping. | |
| 467 | |
| 468 // Make sure the MessagePump does some work for us. | |
| 469 BOOL ret = PostQueuedCompletionStatus(port_.Get(), 0, | |
| 470 reinterpret_cast<ULONG_PTR>(this), | |
| 471 reinterpret_cast<OVERLAPPED*>(this)); | |
| 472 if (ret) | |
| 473 return; // Post worked perfectly. | |
| 474 | |
| 475 // See comment in MessagePumpForUI::ScheduleWork() for this error recovery. | |
| 476 InterlockedExchange(&have_work_, 0); // Clarify that we didn't succeed. | |
| 477 UMA_HISTOGRAM_ENUMERATION("Chrome.MessageLoopProblem", COMPLETION_POST_ERROR, | |
| 478 MESSAGE_LOOP_PROBLEM_MAX); | |
| 479 } | |
| 480 | |
| 481 void MessagePumpForIO::ScheduleDelayedWork(const TimeTicks& delayed_work_time) { | |
| 482 // We know that we can't be blocked right now since this method can only be | |
| 483 // called on the same thread as Run, so we only need to update our record of | |
| 484 // how long to sleep when we do sleep. | |
| 485 delayed_work_time_ = delayed_work_time; | |
| 486 } | |
| 487 | |
| 488 void MessagePumpForIO::RegisterIOHandler(HANDLE file_handle, | |
| 489 IOHandler* handler) { | |
| 490 ULONG_PTR key = HandlerToKey(handler, true); | |
| 491 HANDLE port = CreateIoCompletionPort(file_handle, port_.Get(), key, 1); | |
| 492 DPCHECK(port); | |
| 493 } | |
| 494 | |
| 495 bool MessagePumpForIO::RegisterJobObject(HANDLE job_handle, | |
| 496 IOHandler* handler) { | |
| 497 // Job object notifications use the OVERLAPPED pointer to carry the message | |
| 498 // data. Mark the completion key correspondingly, so we will not try to | |
| 499 // convert OVERLAPPED* to IOContext*. | |
| 500 ULONG_PTR key = HandlerToKey(handler, false); | |
| 501 JOBOBJECT_ASSOCIATE_COMPLETION_PORT info; | |
| 502 info.CompletionKey = reinterpret_cast<void*>(key); | |
| 503 info.CompletionPort = port_.Get(); | |
| 504 return SetInformationJobObject(job_handle, | |
| 505 JobObjectAssociateCompletionPortInformation, | |
| 506 &info, | |
| 507 sizeof(info)) != FALSE; | |
| 508 } | |
| 509 | |
| 510 //----------------------------------------------------------------------------- | |
| 511 // MessagePumpForIO private: | |
| 512 | |
| 513 void MessagePumpForIO::DoRunLoop() { | |
| 514 for (;;) { | |
| 515 // If we do any work, we may create more messages etc., and more work may | |
| 516 // possibly be waiting in another task group. When we (for example) | |
| 517 // WaitForIOCompletion(), there is a good chance there are still more | |
| 518 // messages waiting. On the other hand, when any of these methods return | |
| 519 // having done no work, then it is pretty unlikely that calling them | |
| 520 // again quickly will find any work to do. Finally, if they all say they | |
| 521 // had no work, then it is a good time to consider sleeping (waiting) for | |
| 522 // more work. | |
| 523 | |
| 524 bool more_work_is_plausible = state_->delegate->DoWork(); | |
| 525 if (state_->should_quit) | |
| 526 break; | |
| 527 | |
| 528 more_work_is_plausible |= WaitForIOCompletion(0, NULL); | |
| 529 if (state_->should_quit) | |
| 530 break; | |
| 531 | |
| 532 more_work_is_plausible |= | |
| 533 state_->delegate->DoDelayedWork(&delayed_work_time_); | |
| 534 if (state_->should_quit) | |
| 535 break; | |
| 536 | |
| 537 if (more_work_is_plausible) | |
| 538 continue; | |
| 539 | |
| 540 more_work_is_plausible = state_->delegate->DoIdleWork(); | |
| 541 if (state_->should_quit) | |
| 542 break; | |
| 543 | |
| 544 if (more_work_is_plausible) | |
| 545 continue; | |
| 546 | |
| 547 WaitForWork(); // Wait (sleep) until we have work to do again. | |
| 548 } | |
| 549 } | |
| 550 | |
| 551 // Wait until IO completes, up to the time needed by the timer manager to fire | |
| 552 // the next set of timers. | |
| 553 void MessagePumpForIO::WaitForWork() { | |
| 554 // We do not support nested IO message loops. This is to avoid messy | |
| 555 // recursion problems. | |
| 556 DCHECK_EQ(1, state_->run_depth) << "Cannot nest an IO message loop!"; | |
| 557 | |
| 558 int timeout = GetCurrentDelay(); | |
| 559 if (timeout < 0) // Negative value means no timers waiting. | |
| 560 timeout = INFINITE; | |
| 561 | |
| 562 WaitForIOCompletion(timeout, NULL); | |
| 563 } | |
| 564 | |
| 565 bool MessagePumpForIO::WaitForIOCompletion(DWORD timeout, IOHandler* filter) { | |
| 566 IOItem item; | |
| 567 if (completed_io_.empty() || !MatchCompletedIOItem(filter, &item)) { | |
| 568 // We have to ask the system for another IO completion. | |
| 569 if (!GetIOItem(timeout, &item)) | |
| 570 return false; | |
| 571 | |
| 572 if (ProcessInternalIOItem(item)) | |
| 573 return true; | |
| 574 } | |
| 575 | |
| 576 // If |item.has_valid_io_context| is false then |item.context| does not point | |
| 577 // to a context structure, and so should not be dereferenced, although it may | |
| 578 // still hold valid non-pointer data. | |
| 579 if (!item.has_valid_io_context || item.context->handler) { | |
| 580 if (filter && item.handler != filter) { | |
| 581 // Save this item for later | |
| 582 completed_io_.push_back(item); | |
| 583 } else { | |
| 584 DCHECK(!item.has_valid_io_context || | |
| 585 (item.context->handler == item.handler)); | |
| 586 WillProcessIOEvent(); | |
| 587 item.handler->OnIOCompleted(item.context, item.bytes_transfered, | |
| 588 item.error); | |
| 589 DidProcessIOEvent(); | |
| 590 } | |
| 591 } else { | |
| 592 // The handler must be gone by now, just cleanup the mess. | |
| 593 delete item.context; | |
| 594 } | |
| 595 return true; | |
| 596 } | |
| 597 | |
| 598 // Asks the OS for another IO completion result. | |
| 599 bool MessagePumpForIO::GetIOItem(DWORD timeout, IOItem* item) { | |
| 600 memset(item, 0, sizeof(*item)); | |
| 601 ULONG_PTR key = NULL; | |
| 602 OVERLAPPED* overlapped = NULL; | |
| 603 if (!GetQueuedCompletionStatus(port_.Get(), &item->bytes_transfered, &key, | |
| 604 &overlapped, timeout)) { | |
| 605 if (!overlapped) | |
| 606 return false; // Nothing in the queue. | |
| 607 item->error = GetLastError(); | |
| 608 item->bytes_transfered = 0; | |
| 609 } | |
| 610 | |
| 611 item->handler = KeyToHandler(key, &item->has_valid_io_context); | |
| 612 item->context = reinterpret_cast<IOContext*>(overlapped); | |
| 613 return true; | |
| 614 } | |
| 615 | |
| 616 bool MessagePumpForIO::ProcessInternalIOItem(const IOItem& item) { | |
| 617 if (this == reinterpret_cast<MessagePumpForIO*>(item.context) && | |
| 618 this == reinterpret_cast<MessagePumpForIO*>(item.handler)) { | |
| 619 // This is our internal completion. | |
| 620 DCHECK(!item.bytes_transfered); | |
| 621 InterlockedExchange(&have_work_, 0); | |
| 622 return true; | |
| 623 } | |
| 624 return false; | |
| 625 } | |
| 626 | |
| 627 // Returns a completion item that was previously received. | |
| 628 bool MessagePumpForIO::MatchCompletedIOItem(IOHandler* filter, IOItem* item) { | |
| 629 DCHECK(!completed_io_.empty()); | |
| 630 for (std::list<IOItem>::iterator it = completed_io_.begin(); | |
| 631 it != completed_io_.end(); ++it) { | |
| 632 if (!filter || it->handler == filter) { | |
| 633 *item = *it; | |
| 634 completed_io_.erase(it); | |
| 635 return true; | |
| 636 } | |
| 637 } | |
| 638 return false; | |
| 639 } | |
| 640 | |
| 641 void MessagePumpForIO::AddIOObserver(IOObserver *obs) { | |
| 642 io_observers_.AddObserver(obs); | |
| 643 } | |
| 644 | |
| 645 void MessagePumpForIO::RemoveIOObserver(IOObserver *obs) { | |
| 646 io_observers_.RemoveObserver(obs); | |
| 647 } | |
| 648 | |
| 649 void MessagePumpForIO::WillProcessIOEvent() { | |
| 650 FOR_EACH_OBSERVER(IOObserver, io_observers_, WillProcessIOEvent()); | |
| 651 } | |
| 652 | |
| 653 void MessagePumpForIO::DidProcessIOEvent() { | |
| 654 FOR_EACH_OBSERVER(IOObserver, io_observers_, DidProcessIOEvent()); | |
| 655 } | |
| 656 | |
| 657 // static | |
| 658 ULONG_PTR MessagePumpForIO::HandlerToKey(IOHandler* handler, | |
| 659 bool has_valid_io_context) { | |
| 660 ULONG_PTR key = reinterpret_cast<ULONG_PTR>(handler); | |
| 661 | |
| 662 // |IOHandler| is at least pointer-size aligned, so the lowest two bits are | |
| 663 // always cleared. We use the lowest bit to distinguish completion keys with | |
| 664 // and without the associated |IOContext|. | |
| 665 DCHECK_EQ(key & 1, 0u); | |
| 666 | |
| 667 // Mark the completion key as context-less. | |
| 668 if (!has_valid_io_context) | |
| 669 key = key | 1; | |
| 670 return key; | |
| 671 } | |
| 672 | |
| 673 // static | |
| 674 MessagePumpForIO::IOHandler* MessagePumpForIO::KeyToHandler( | |
| 675 ULONG_PTR key, | |
| 676 bool* has_valid_io_context) { | |
| 677 *has_valid_io_context = ((key & 1) == 0); | |
| 678 return reinterpret_cast<IOHandler*>(key & ~static_cast<ULONG_PTR>(1)); | |
| 679 } | |
| 680 | |
| 681 } // namespace base | |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 1446363003:
Deleted OS_WIN and all Windows specific files from base. (Closed)
Base URL: https://github.com/domokit/mojo.git@base_tests