| // Copyright 2013 The Flutter Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef FLUTTER_SHELL_PLATFORM_WINDOWS_WIN32_TASK_RUNNER_H_ |
| #define FLUTTER_SHELL_PLATFORM_WINDOWS_WIN32_TASK_RUNNER_H_ |
| |
| #include <windows.h> |
| |
| #include <chrono> |
| #include <deque> |
| #include <functional> |
| #include <mutex> |
| #include <queue> |
| #include <thread> |
| |
| #include "flutter/shell/platform/embedder/embedder.h" |
| |
| namespace flutter { |
| |
| // A custom task runner that integrates with user32 GetMessage semantics so that |
| // host app can own its own message loop and flutter still gets to process |
| // tasks on a timely basis. |
| class Win32TaskRunner { |
| public: |
| using TaskExpiredCallback = std::function<void(const FlutterTask*)>; |
| Win32TaskRunner(DWORD main_thread_id, |
| const TaskExpiredCallback& on_task_expired); |
| |
| ~Win32TaskRunner(); |
| |
| // Returns if the current thread is the thread used by the win32 event loop. |
| bool RunsTasksOnCurrentThread() const; |
| |
| std::chrono::nanoseconds ProcessTasks(); |
| |
| // Post a Flutter engine tasks to the event loop for delayed execution. |
| void PostTask(FlutterTask flutter_task, uint64_t flutter_target_time_nanos); |
| |
| private: |
| using TaskTimePoint = std::chrono::steady_clock::time_point; |
| struct Task { |
| uint64_t order; |
| TaskTimePoint fire_time; |
| FlutterTask task; |
| |
| struct Comparer { |
| bool operator()(const Task& a, const Task& b) { |
| if (a.fire_time == b.fire_time) { |
| return a.order > b.order; |
| } |
| return a.fire_time > b.fire_time; |
| } |
| }; |
| }; |
| DWORD main_thread_id_; |
| TaskExpiredCallback on_task_expired_; |
| std::mutex task_queue_mutex_; |
| std::priority_queue<Task, std::deque<Task>, Task::Comparer> task_queue_; |
| |
| Win32TaskRunner(const Win32TaskRunner&) = delete; |
| |
| Win32TaskRunner& operator=(const Win32TaskRunner&) = delete; |
| |
| static TaskTimePoint TimePointFromFlutterTime( |
| uint64_t flutter_target_time_nanos); |
| }; |
| |
| } // namespace flutter |
| |
| #endif // FLUTTER_SHELL_PLATFORM_WINDOWS_WIN32_TASK_RUNNER_H_ |