license.bot | f003cfe | 2008-08-24 09:55:55 +0900 | [diff] [blame^] | 1 | // Copyright (c) 2006-2008 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. |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 4 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 5 | #ifndef BASE_MESSAGE_LOOP_H_ |
| 6 | #define BASE_MESSAGE_LOOP_H_ |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 7 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 8 | #include <deque> |
| 9 | #include <queue> |
| 10 | #include <string> |
| 11 | #include <vector> |
| 12 | |
| 13 | #include "base/histogram.h" |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 14 | #include "base/message_pump.h" |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 15 | #include "base/observer_list.h" |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 16 | #include "base/ref_counted.h" |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 17 | #include "base/task.h" |
| 18 | #include "base/timer.h" |
| 19 | #include "base/thread_local_storage.h" |
| 20 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 21 | #if defined(OS_WIN) |
| 22 | // We need this to declare base::MessagePumpWin::Dispatcher, which we should |
| 23 | // really just eliminate. |
| 24 | #include "base/message_pump_win.h" |
| 25 | #endif |
darin@google.com | 6ddeb84 | 2008-08-15 16:31:20 +0900 | [diff] [blame] | 26 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 27 | // A MessageLoop is used to process events for a particular thread. There is |
| 28 | // at most one MessageLoop instance per thread. |
| 29 | // |
| 30 | // Events include at a minimum Task instances submitted to PostTask or those |
| 31 | // managed by TimerManager. Depending on the type of message pump used by the |
| 32 | // MessageLoop other events such as UI messages may be processed. On Windows |
| 33 | // APC calls (as time permits) and signals sent to a registered set of HANDLEs |
| 34 | // may also be processed. |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 35 | // |
| 36 | // NOTE: Unless otherwise specified, a MessageLoop's methods may only be called |
| 37 | // on the thread where the MessageLoop's Run method executes. |
| 38 | // |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 39 | // NOTE: MessageLoop has task reentrancy protection. This means that if a |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 40 | // task is being processed, a second task cannot start until the first task is |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 41 | // finished. Reentrancy can happen when processing a task, and an inner |
| 42 | // message pump is created. That inner pump then processes native messages |
| 43 | // which could implicitly start an inner task. Inner message pumps are created |
| 44 | // with dialogs (DialogBox), common dialogs (GetOpenFileName), OLE functions |
| 45 | // (DoDragDrop), printer functions (StartDoc) and *many* others. |
| 46 | // |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 47 | // Sample workaround when inner task processing is needed: |
| 48 | // bool old_state = MessageLoop::current()->NestableTasksAllowed(); |
| 49 | // MessageLoop::current()->SetNestableTasksAllowed(true); |
| 50 | // HRESULT hr = DoDragDrop(...); // Implicitly runs a modal message loop here. |
| 51 | // MessageLoop::current()->SetNestableTasksAllowed(old_state); |
| 52 | // // Process hr (the result returned by DoDragDrop(). |
| 53 | // |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 54 | // Please be SURE your task is reentrant (nestable) and all global variables |
| 55 | // are stable and accessible before calling SetNestableTasksAllowed(true). |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 56 | // |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 57 | class MessageLoop : public base::MessagePump::Delegate { |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 58 | public: |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 59 | static void EnableHistogrammer(bool enable_histogrammer); |
| 60 | |
darin@google.com | 3810032 | 2008-08-07 06:27:02 +0900 | [diff] [blame] | 61 | // A DestructionObserver is notified when the current MessageLoop is being |
| 62 | // destroyed. These obsevers are notified prior to MessageLoop::current() |
| 63 | // being changed to return NULL. This gives interested parties the chance to |
| 64 | // do final cleanup that depends on the MessageLoop. |
| 65 | // |
| 66 | // NOTE: Any tasks posted to the MessageLoop during this notification will |
| 67 | // not be run. Instead, they will be deleted. |
| 68 | // |
| 69 | class DestructionObserver { |
| 70 | public: |
| 71 | virtual ~DestructionObserver() {} |
| 72 | virtual void WillDestroyCurrentMessageLoop() = 0; |
| 73 | }; |
| 74 | |
| 75 | // Add a DestructionObserver, which will start receiving notifications |
| 76 | // immediately. |
| 77 | void AddDestructionObserver(DestructionObserver* destruction_observer); |
| 78 | |
| 79 | // Remove a DestructionObserver. It is safe to call this method while a |
| 80 | // DestructionObserver is receiving a notification callback. |
| 81 | void RemoveDestructionObserver(DestructionObserver* destruction_observer); |
| 82 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 83 | // Call the task's Run method asynchronously from within a message loop at |
| 84 | // some point in the future. With the PostTask variant, tasks are invoked in |
| 85 | // FIFO order, inter-mixed with normal UI event processing. With the |
| 86 | // PostDelayedTask variant, tasks are called after at least approximately |
| 87 | // 'delay_ms' have elapsed. |
| 88 | // |
| 89 | // The MessageLoop takes ownership of the Task, and deletes it after it |
| 90 | // has been Run(). |
| 91 | // |
| 92 | // NOTE: This method may be called on any thread. The Task will be invoked |
| 93 | // on the thread that executes MessageLoop::Run(). |
| 94 | |
| 95 | void PostTask(const tracked_objects::Location& from_here, Task* task) { |
| 96 | PostDelayedTask(from_here, task, 0); |
| 97 | } |
| 98 | |
| 99 | void PostDelayedTask(const tracked_objects::Location& from_here, Task* task, |
| 100 | int delay_ms); |
| 101 | |
| 102 | // A variant on PostTask that deletes the given object. This is useful |
| 103 | // if the object needs to live until the next run of the MessageLoop (for |
| 104 | // example, deleting a RenderProcessHost from within an IPC callback is not |
| 105 | // good). |
| 106 | // |
| 107 | // NOTE: This method may be called on any thread. The object will be deleted |
| 108 | // on the thread that executes MessageLoop::Run(). If this is not the same |
| 109 | // as the thread that calls PostDelayedTask(FROM_HERE, ), then T MUST inherit |
| 110 | // from RefCountedThreadSafe<T>! |
| 111 | template <class T> |
| 112 | void DeleteSoon(const tracked_objects::Location& from_here, T* object) { |
| 113 | PostTask(from_here, new DeleteTask<T>(object)); |
| 114 | } |
| 115 | |
| 116 | // A variant on PostTask that releases the given reference counted object |
| 117 | // (by calling its Release method). This is useful if the object needs to |
| 118 | // live until the next run of the MessageLoop, or if the object needs to be |
| 119 | // released on a particular thread. |
| 120 | // |
| 121 | // NOTE: This method may be called on any thread. The object will be |
| 122 | // released (and thus possibly deleted) on the thread that executes |
| 123 | // MessageLoop::Run(). If this is not the same as the thread that calls |
| 124 | // PostDelayedTask(FROM_HERE, ), then T MUST inherit from |
| 125 | // RefCountedThreadSafe<T>! |
| 126 | template <class T> |
| 127 | void ReleaseSoon(const tracked_objects::Location& from_here, T* object) { |
| 128 | PostTask(from_here, new ReleaseTask<T>(object)); |
| 129 | } |
| 130 | |
jar@google.com | b4d1bff | 2008-07-31 04:03:59 +0900 | [diff] [blame] | 131 | // Run the message loop. |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 132 | void Run(); |
| 133 | |
jar@google.com | 9239e02 | 2008-07-31 22:10:20 +0900 | [diff] [blame] | 134 | // Process all pending tasks, windows messages, etc., but don't wait/sleep. |
| 135 | // Return as soon as all items that can be run are taken care of. |
| 136 | void RunAllPending(); |
jar@google.com | b4d1bff | 2008-07-31 04:03:59 +0900 | [diff] [blame] | 137 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 138 | // Signals the Run method to return after it is done processing all pending |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 139 | // messages. This method may only be called on the same thread that called |
| 140 | // Run, and Run must still be on the call stack. |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 141 | // |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 142 | // Use QuitTask if you need to Quit another thread's MessageLoop, but note |
| 143 | // that doing so is fairly dangerous if the target thread makes nested calls |
| 144 | // to MessageLoop::Run. The problem being that you won't know which nested |
| 145 | // run loop you are quiting, so be careful! |
| 146 | // |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 147 | void Quit(); |
| 148 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 149 | // Invokes Quit on the current MessageLoop when run. Useful to schedule an |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 150 | // arbitrary MessageLoop to Quit. |
| 151 | class QuitTask : public Task { |
| 152 | public: |
| 153 | virtual void Run() { |
| 154 | MessageLoop::current()->Quit(); |
| 155 | } |
| 156 | }; |
| 157 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 158 | // Normally, it is not necessary to instantiate a MessageLoop. Instead, it |
| 159 | // is typical to make use of the current thread's MessageLoop instance. |
| 160 | MessageLoop(); |
| 161 | ~MessageLoop(); |
| 162 | |
| 163 | // Optional call to connect the thread name with this loop. |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 164 | void set_thread_name(const std::string& thread_name) { |
| 165 | DCHECK(thread_name_.empty()) << "Should not rename this thread!"; |
| 166 | thread_name_ = thread_name; |
| 167 | } |
darin@google.com | 3810032 | 2008-08-07 06:27:02 +0900 | [diff] [blame] | 168 | const std::string& thread_name() const { return thread_name_; } |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 169 | |
| 170 | // Returns the MessageLoop object for the current thread, or null if none. |
| 171 | static MessageLoop* current() { |
evanm@google.com | f26fd3a | 2008-08-21 07:54:52 +0900 | [diff] [blame] | 172 | return static_cast<MessageLoop*>(tls_index_.Get()); |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 173 | } |
| 174 | |
| 175 | // Returns the TimerManager object for the current thread. |
| 176 | TimerManager* timer_manager() { return &timer_manager_; } |
| 177 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 178 | // Enables or disables the recursive task processing. This happens in the case |
| 179 | // of recursive message loops. Some unwanted message loop may occurs when |
| 180 | // using common controls or printer functions. By default, recursive task |
| 181 | // processing is disabled. |
| 182 | // |
| 183 | // The specific case where tasks get queued is: |
| 184 | // - The thread is running a message loop. |
| 185 | // - It receives a task #1 and execute it. |
| 186 | // - The task #1 implicitly start a message loop, like a MessageBox in the |
| 187 | // unit test. This can also be StartDoc or GetSaveFileName. |
| 188 | // - The thread receives a task #2 before or while in this second message |
| 189 | // loop. |
| 190 | // - With NestableTasksAllowed set to true, the task #2 will run right away. |
| 191 | // Otherwise, it will get executed right after task #1 completes at "thread |
| 192 | // message loop level". |
| 193 | void SetNestableTasksAllowed(bool allowed); |
| 194 | bool NestableTasksAllowed() const; |
| 195 | |
| 196 | // Enables or disables the restoration during an exception of the unhandled |
| 197 | // exception filter that was active when Run() was called. This can happen |
| 198 | // if some third party code call SetUnhandledExceptionFilter() and never |
| 199 | // restores the previous filter. |
| 200 | void set_exception_restoration(bool restore) { |
| 201 | exception_restoration_ = restore; |
| 202 | } |
| 203 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 204 | //---------------------------------------------------------------------------- |
| 205 | #if defined(OS_WIN) |
| 206 | // Backwards-compat for the old Windows-specific MessageLoop API. These APIs |
| 207 | // are deprecated. |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 208 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 209 | typedef base::MessagePumpWin::Dispatcher Dispatcher; |
| 210 | typedef base::MessagePumpWin::Observer Observer; |
| 211 | typedef base::MessagePumpWin::Watcher Watcher; |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 212 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 213 | void Run(Dispatcher* dispatcher); |
| 214 | |
| 215 | void WatchObject(HANDLE object, Watcher* watcher) { |
| 216 | pump_win()->WatchObject(object, watcher); |
| 217 | } |
| 218 | void AddObserver(Observer* observer) { |
| 219 | pump_win()->AddObserver(observer); |
| 220 | } |
| 221 | void RemoveObserver(Observer* observer) { |
| 222 | pump_win()->RemoveObserver(observer); |
| 223 | } |
| 224 | void WillProcessMessage(const MSG& message) { |
| 225 | pump_win()->WillProcessMessage(message); |
| 226 | } |
| 227 | void DidProcessMessage(const MSG& message) { |
| 228 | pump_win()->DidProcessMessage(message); |
| 229 | } |
| 230 | void PumpOutPendingPaintMessages() { |
| 231 | pump_win()->PumpOutPendingPaintMessages(); |
| 232 | } |
| 233 | #endif // defined(OS_WIN) |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 234 | |
| 235 | //---------------------------------------------------------------------------- |
| 236 | private: |
darin@google.com | ee6fa72 | 2008-08-13 08:25:43 +0900 | [diff] [blame] | 237 | friend class TimerManager; // So it can call DidChangeNextTimerExpiry |
| 238 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 239 | struct RunState { |
| 240 | // Used to count how many Run() invocations are on the stack. |
| 241 | int run_depth; |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 242 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 243 | // Used to record that Quit() was called, or that we should quit the pump |
| 244 | // once it becomes idle. |
| 245 | bool quit_received; |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 246 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 247 | #if defined(OS_WIN) |
| 248 | base::MessagePumpWin::Dispatcher* dispatcher; |
| 249 | #endif |
| 250 | }; |
| 251 | |
| 252 | class AutoRunState : RunState { |
| 253 | public: |
| 254 | AutoRunState(MessageLoop* loop); |
| 255 | ~AutoRunState(); |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 256 | private: |
| 257 | MessageLoop* loop_; |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 258 | RunState* previous_state_; |
| 259 | }; |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 260 | |
| 261 | // A prioritized queue with interface that mostly matches std::queue<>. |
| 262 | // For debugging/performance testing, you can swap in std::queue<Task*>. |
| 263 | class PrioritizedTaskQueue { |
| 264 | public: |
| 265 | PrioritizedTaskQueue() : next_sequence_number_(0) {} |
| 266 | ~PrioritizedTaskQueue() {} |
| 267 | void pop() { queue_.pop(); } |
| 268 | bool empty() { return queue_.empty(); } |
| 269 | size_t size() { return queue_.size(); } |
| 270 | Task* front() { return queue_.top().task(); } |
| 271 | void push(Task * task); |
| 272 | |
| 273 | private: |
| 274 | class PrioritizedTask { |
| 275 | public: |
| 276 | PrioritizedTask(Task* task, int sequence_number) |
| 277 | : task_(task), |
| 278 | sequence_number_(sequence_number), |
| 279 | priority_(task->priority()) {} |
darin@google.com | 3810032 | 2008-08-07 06:27:02 +0900 | [diff] [blame] | 280 | Task* task() const { return task_; } |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 281 | bool operator < (PrioritizedTask const & right) const ; |
| 282 | |
| 283 | private: |
| 284 | Task* task_; |
| 285 | // Number to ensure (default) FIFO ordering in a PriorityQueue. |
| 286 | int sequence_number_; |
| 287 | // Priority of task when pushed. |
| 288 | int priority_; |
| 289 | }; // class PrioritizedTask |
| 290 | |
| 291 | std::priority_queue<PrioritizedTask> queue_; |
| 292 | // Default sequence number used when push'ing (monotonically decreasing). |
| 293 | int next_sequence_number_; |
| 294 | DISALLOW_EVIL_CONSTRUCTORS(PrioritizedTaskQueue); |
| 295 | }; |
| 296 | |
| 297 | // Implementation of a TaskQueue as a null terminated list, with end pointers. |
| 298 | class TaskQueue { |
| 299 | public: |
| 300 | TaskQueue() : first_(NULL), last_(NULL) {} |
| 301 | void Push(Task* task); |
| 302 | Task* Pop(); // Extract the next Task from the queue, and return it. |
| 303 | bool Empty() const { return !first_; } |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 304 | private: |
| 305 | Task* first_; |
| 306 | Task* last_; |
| 307 | }; |
| 308 | |
| 309 | // Implementation of a Task queue that automatically switches into a priority |
| 310 | // queue if it observes any non-zero priorities in tasks. |
| 311 | class OptionallyPrioritizedTaskQueue { |
| 312 | public: |
| 313 | OptionallyPrioritizedTaskQueue() : use_priority_queue_(false) {} |
| 314 | void Push(Task* task); |
| 315 | Task* Pop(); // Extract next Task from queue, and return it. |
| 316 | bool Empty(); |
| 317 | bool use_priority_queue() const { return use_priority_queue_; } |
| 318 | |
| 319 | private: |
| 320 | bool use_priority_queue_; |
| 321 | PrioritizedTaskQueue prioritized_queue_; |
| 322 | TaskQueue queue_; |
| 323 | DISALLOW_EVIL_CONSTRUCTORS(OptionallyPrioritizedTaskQueue); |
| 324 | }; |
| 325 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 326 | #if defined(OS_WIN) |
| 327 | base::MessagePumpWin* pump_win() { |
| 328 | return static_cast<base::MessagePumpWin*>(pump_.get()); |
| 329 | } |
| 330 | #endif |
jar@google.com | b4d1bff | 2008-07-31 04:03:59 +0900 | [diff] [blame] | 331 | |
| 332 | // A function to encapsulate all the exception handling capability in the |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 333 | // stacks around the running of a main message loop. It will run the message |
| 334 | // loop in a SEH try block or not depending on the set_SEH_restoration() |
| 335 | // flag. |
| 336 | void RunHandler(); |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 337 | |
jar@google.com | b4d1bff | 2008-07-31 04:03:59 +0900 | [diff] [blame] | 338 | // A surrounding stack frame around the running of the message loop that |
| 339 | // supports all saving and restoring of state, as is needed for any/all (ugly) |
| 340 | // recursive calls. |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 341 | void RunInternal(); |
darin@google.com | 6ddeb84 | 2008-08-15 16:31:20 +0900 | [diff] [blame] | 342 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 343 | // Called to process any delayed non-nestable tasks. |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 344 | bool ProcessNextDelayedNonNestableTask(); |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 345 | |
| 346 | //---------------------------------------------------------------------------- |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 347 | // Run a work_queue_ task or new_task, and delete it (if it was processed by |
| 348 | // PostTask). If there are queued tasks, the oldest one is executed and |
| 349 | // new_task is queued. new_task is optional and can be NULL. In this NULL |
| 350 | // case, the method will run one pending task (if any exist). Returns true if |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 351 | // it executes a task. Queued tasks accumulate only when there is a |
| 352 | // non-nestable task currently processing, in which case the new_task is |
| 353 | // appended to the list work_queue_. Such re-entrancy generally happens when |
| 354 | // an unrequested message pump (typical of a native dialog) is executing in |
| 355 | // the context of a task. |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 356 | bool QueueOrRunTask(Task* new_task); |
| 357 | |
| 358 | // Runs the specified task and deletes it. |
| 359 | void RunTask(Task* task); |
| 360 | |
| 361 | // Make state adjustments just before and after running tasks so that we can |
| 362 | // continue to work if a native message loop is employed during a task. |
| 363 | void BeforeTaskRunSetup(); |
| 364 | void AfterTaskRunRestore(); |
| 365 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 366 | // Load tasks from the incoming_queue_ into work_queue_ if the latter is |
| 367 | // empty. The former requires a lock to access, while the latter is directly |
| 368 | // accessible on this thread. |
| 369 | void ReloadWorkQueue(); |
| 370 | |
| 371 | // Delete tasks that haven't run yet without running them. Used in the |
| 372 | // destructor to make sure all the task's destructors get called. |
| 373 | void DeletePendingTasks(); |
| 374 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 375 | // Post a task to our incomming queue. |
darin@google.com | 3810032 | 2008-08-07 06:27:02 +0900 | [diff] [blame] | 376 | void PostTaskInternal(Task* task); |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 377 | |
darin@google.com | ee6fa72 | 2008-08-13 08:25:43 +0900 | [diff] [blame] | 378 | // Called by the TimerManager when its next timer changes. |
| 379 | void DidChangeNextTimerExpiry(); |
| 380 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 381 | // Entry point for TimerManager to request the Run() of a task. If we |
| 382 | // created the task during an PostTask(FROM_HERE, ), then we will also |
| 383 | // perform destructions, and we'll have the option of queueing the task. If |
| 384 | // we didn't create the timer, then we will Run it immediately. |
| 385 | bool RunTimerTask(Timer* timer); |
| 386 | |
| 387 | // Since some Timer's are owned by MessageLoop, the TimerManager (when it is |
| 388 | // being destructed) passses us the timers to discard (without doing a Run()). |
| 389 | void DiscardTimer(Timer* timer); |
| 390 | |
| 391 | // base::MessagePump::Delegate methods: |
| 392 | virtual bool DoWork(); |
darin@google.com | 6393bed | 2008-08-20 15:30:58 +0900 | [diff] [blame] | 393 | virtual bool DoDelayedWork(Time* next_delayed_work_time); |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 394 | virtual bool DoIdleWork(); |
| 395 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 396 | // Start recording histogram info about events and action IF it was enabled |
| 397 | // and IF the statistics recorder can accept a registration of our histogram. |
| 398 | void StartHistogrammer(); |
| 399 | |
| 400 | // Add occurence of event to our histogram, so that we can see what is being |
| 401 | // done in a specific MessageLoop instance (i.e., specific thread). |
| 402 | // If message_histogram_ is NULL, this is a no-op. |
| 403 | void HistogramEvent(int event); |
| 404 | |
| 405 | static TLSSlot tls_index_; |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 406 | static const LinearHistogram::DescriptionPair event_descriptions_[]; |
| 407 | static bool enable_histogrammer_; |
| 408 | |
| 409 | TimerManager timer_manager_; |
| 410 | |
| 411 | // A list of tasks that need to be processed by this instance. Note that this |
| 412 | // queue is only accessed (push/pop) by our current thread. |
| 413 | // As an optimization, when we don't need to use the prioritization of |
| 414 | // work_queue_, we use a null terminated list (TaskQueue) as our |
| 415 | // implementation of the queue. This saves on memory (list uses pointers |
| 416 | // internal to Task) and probably runs faster than the priority queue when |
| 417 | // there was no real prioritization. |
| 418 | OptionallyPrioritizedTaskQueue work_queue_; |
| 419 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 420 | scoped_refptr<base::MessagePump> pump_; |
darin@google.com | 3810032 | 2008-08-07 06:27:02 +0900 | [diff] [blame] | 421 | |
darin@google.com | 965e534 | 2008-08-06 08:16:41 +0900 | [diff] [blame] | 422 | ObserverList<DestructionObserver> destruction_observers_; |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 423 | // A recursion block that prevents accidentally running additonal tasks when |
| 424 | // insider a (accidentally induced?) nested message pump. |
| 425 | bool nestable_tasks_allowed_; |
| 426 | |
| 427 | bool exception_restoration_; |
| 428 | |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 429 | std::string thread_name_; |
| 430 | // A profiling histogram showing the counts of various messages and events. |
| 431 | scoped_ptr<LinearHistogram> message_histogram_; |
| 432 | |
| 433 | // A null terminated list which creates an incoming_queue of tasks that are |
| 434 | // aquired under a mutex for processing on this instance's thread. These tasks |
| 435 | // have not yet been sorted out into items for our work_queue_ vs items that |
| 436 | // will be handled by the TimerManager. |
| 437 | TaskQueue incoming_queue_; |
| 438 | // Protect access to incoming_queue_. |
| 439 | Lock incoming_queue_lock_; |
| 440 | |
| 441 | // A null terminated list of non-nestable tasks that we had to delay because |
| 442 | // when it came time to execute them we were in a nested message loop. They |
| 443 | // will execute once we're out of nested message loops. |
| 444 | TaskQueue delayed_non_nestable_queue_; |
| 445 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 446 | RunState* state_; |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 447 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 448 | DISALLOW_COPY_AND_ASSIGN(MessageLoop); |
initial.commit | 3f4a732 | 2008-07-27 06:49:38 +0900 | [diff] [blame] | 449 | }; |
| 450 | |
darin@google.com | 981f355 | 2008-08-16 12:09:05 +0900 | [diff] [blame] | 451 | #endif // BASE_MESSAGE_LOOP_H_ |
license.bot | f003cfe | 2008-08-24 09:55:55 +0900 | [diff] [blame^] | 452 | |