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 #ifndef BASE_PENDING_TASK_H_ 6 #define BASE_PENDING_TASK_H_ 7 8 #include <array> 9 10 #include "base/base_export.h" 11 #include "base/callback.h" 12 #include "base/containers/queue.h" 13 #include "base/location.h" 14 #include "base/time/time.h" 15 16 namespace base { 17 18 enum class Nestable { 19 kNonNestable, 20 kNestable, 21 }; 22 23 // Contains data about a pending task. Stored in TaskQueue and DelayedTaskQueue 24 // for use by classes that queue and execute tasks. 25 struct BASE_EXPORT PendingTask { 26 PendingTask(const Location& posted_from, 27 OnceClosure task, 28 TimeTicks delayed_run_time = TimeTicks(), 29 Nestable nestable = Nestable::kNestable); 30 PendingTask(PendingTask&& other); 31 ~PendingTask(); 32 33 PendingTask& operator=(PendingTask&& other); 34 35 // Used to support sorting. 36 bool operator<(const PendingTask& other) const; 37 38 // The task to run. 39 OnceClosure task; 40 41 // The site this PendingTask was posted from. 42 Location posted_from; 43 44 // The time when the task should be run. 45 base::TimeTicks delayed_run_time; 46 47 // Chain of up-to-four symbols of the parent tasks which led to this one being 48 // posted. 49 std::array<const void*, 4> task_backtrace = {}; 50 51 // Secondary sort key for run time. 52 int sequence_num = 0; 53 54 // OK to dispatch from a nested loop. 55 Nestable nestable; 56 57 // Needs high resolution timers. 58 bool is_high_res = false; 59 }; 60 61 using TaskQueue = base::queue<PendingTask>; 62 63 // PendingTasks are sorted by their |delayed_run_time| property. 64 using DelayedTaskQueue = std::priority_queue<base::PendingTask>; 65 66 } // namespace base 67 68 #endif // BASE_PENDING_TASK_H_ 69
