Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2012 the V8 project 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 V8_HEAP_INCREMENTAL_MARKING_JOB_H_ |
| 6 | #define V8_HEAP_INCREMENTAL_MARKING_JOB_H_ |
| 7 | |
| 8 | #include "src/cancelable-task.h" |
| 9 | |
| 10 | namespace v8 { |
| 11 | namespace internal { |
| 12 | |
| 13 | class Heap; |
| 14 | class Isolate; |
| 15 | |
| 16 | // The incremental marking job uses platform tasks to perform incremental |
| 17 | // marking steps. The job posts an idle and a delayed task with a large delay. |
| 18 | // The delayed task performs steps only if the idle task is not making progress. |
| 19 | // We expect this to be a rare event since incremental marking should finish |
| 20 | // quickly with the help of the mutator and the idle task. |
| 21 | // The delayed task guarantees that we eventually finish incremental marking |
| 22 | // even if the mutator becomes idle and the platform stops running idle tasks, |
| 23 | // which can happen for background tabs in Chrome. |
| 24 | class IncrementalMarkingJob { |
| 25 | public: |
| 26 | class IdleTask : public CancelableIdleTask { |
| 27 | public: |
| 28 | explicit IdleTask(Isolate* isolate, IncrementalMarkingJob* job) |
| 29 | : CancelableIdleTask(isolate), job_(job) {} |
| 30 | enum Progress { kDone, kMoreWork }; |
| 31 | static Progress Step(Heap* heap, double deadline_in_ms); |
| 32 | // CancelableIdleTask overrides. |
| 33 | void RunInternal(double deadline_in_seconds) override; |
| 34 | |
| 35 | private: |
| 36 | IncrementalMarkingJob* job_; |
| 37 | }; |
| 38 | |
| 39 | class DelayedTask : public CancelableTask { |
| 40 | public: |
| 41 | explicit DelayedTask(Isolate* isolate, IncrementalMarkingJob* job) |
| 42 | : CancelableTask(isolate), job_(job) {} |
| 43 | static void Step(Heap* heap); |
| 44 | // CancelableTask overrides. |
| 45 | void RunInternal() override; |
| 46 | |
| 47 | private: |
| 48 | IncrementalMarkingJob* job_; |
| 49 | }; |
| 50 | |
| 51 | // Delay of the delayed task. |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 52 | static const double kLongDelayInSeconds; |
| 53 | static const double kShortDelayInSeconds; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 54 | |
| 55 | IncrementalMarkingJob() |
| 56 | : idle_task_pending_(false), |
| 57 | delayed_task_pending_(false), |
| 58 | made_progress_since_last_delayed_task_(false) {} |
| 59 | |
| 60 | bool ShouldForceMarkingStep() { |
| 61 | return !made_progress_since_last_delayed_task_; |
| 62 | } |
| 63 | |
| 64 | bool IdleTaskPending() { return idle_task_pending_; } |
| 65 | |
| 66 | void Start(Heap* heap); |
| 67 | |
| 68 | void NotifyIdleTask(); |
| 69 | void NotifyDelayedTask(); |
| 70 | void NotifyIdleTaskProgress(); |
| 71 | void ScheduleIdleTask(Heap* heap); |
| 72 | void ScheduleDelayedTask(Heap* heap); |
| 73 | |
| 74 | private: |
| 75 | bool idle_task_pending_; |
| 76 | bool delayed_task_pending_; |
| 77 | bool made_progress_since_last_delayed_task_; |
| 78 | }; |
| 79 | } // namespace internal |
| 80 | } // namespace v8 |
| 81 | |
| 82 | #endif // V8_HEAP_INCREMENTAL_MARKING_JOB_H_ |