Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 1 | // Copyright 2015 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 | #include "src/heap/scavenge-job.h" |
| 6 | |
| 7 | #include "src/base/platform/time.h" |
| 8 | #include "src/heap/heap-inl.h" |
| 9 | #include "src/heap/heap.h" |
| 10 | #include "src/isolate.h" |
| 11 | #include "src/v8.h" |
| 12 | |
| 13 | namespace v8 { |
| 14 | namespace internal { |
| 15 | |
| 16 | |
| 17 | const double ScavengeJob::kMaxAllocationLimitAsFractionOfNewSpace = 0.8; |
| 18 | |
| 19 | void ScavengeJob::IdleTask::RunInternal(double deadline_in_seconds) { |
| 20 | Heap* heap = isolate()->heap(); |
| 21 | double deadline_in_ms = |
| 22 | deadline_in_seconds * |
| 23 | static_cast<double>(base::Time::kMillisecondsPerSecond); |
| 24 | double start_ms = heap->MonotonicallyIncreasingTimeInMs(); |
| 25 | double idle_time_in_ms = deadline_in_ms - start_ms; |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 26 | double scavenge_speed_in_bytes_per_ms = |
| 27 | heap->tracer()->ScavengeSpeedInBytesPerMillisecond(); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 28 | size_t new_space_size = heap->new_space()->Size(); |
| 29 | size_t new_space_capacity = heap->new_space()->Capacity(); |
| 30 | |
| 31 | job_->NotifyIdleTask(); |
| 32 | |
| 33 | if (ReachedIdleAllocationLimit(scavenge_speed_in_bytes_per_ms, new_space_size, |
| 34 | new_space_capacity)) { |
| 35 | if (EnoughIdleTimeForScavenge( |
| 36 | idle_time_in_ms, scavenge_speed_in_bytes_per_ms, new_space_size)) { |
| 37 | heap->CollectGarbage(NEW_SPACE, "idle task: scavenge"); |
| 38 | } else { |
| 39 | // Immediately request another idle task that can get larger idle time. |
| 40 | job_->RescheduleIdleTask(heap); |
| 41 | } |
| 42 | } |
| 43 | } |
| 44 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 45 | bool ScavengeJob::ReachedIdleAllocationLimit( |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 46 | double scavenge_speed_in_bytes_per_ms, size_t new_space_size, |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 47 | size_t new_space_capacity) { |
| 48 | if (scavenge_speed_in_bytes_per_ms == 0) { |
| 49 | scavenge_speed_in_bytes_per_ms = kInitialScavengeSpeedInBytesPerMs; |
| 50 | } |
| 51 | |
| 52 | // Set the allocation limit to the number of bytes we can scavenge in an |
| 53 | // average idle task. |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 54 | double allocation_limit = kAverageIdleTimeMs * scavenge_speed_in_bytes_per_ms; |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 55 | |
| 56 | // Keep the limit smaller than the new space capacity. |
| 57 | allocation_limit = |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 58 | Min<double>(allocation_limit, |
| 59 | new_space_capacity * kMaxAllocationLimitAsFractionOfNewSpace); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 60 | // Adjust the limit to take into account bytes that will be allocated until |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 61 | // the next check and keep the limit large enough to avoid scavenges in tiny |
| 62 | // new space. |
| 63 | allocation_limit = |
| 64 | Max<double>(allocation_limit - kBytesAllocatedBeforeNextIdleTask, |
| 65 | kMinAllocationLimit); |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 66 | |
| 67 | return allocation_limit <= new_space_size; |
| 68 | } |
| 69 | |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 70 | bool ScavengeJob::EnoughIdleTimeForScavenge( |
Ben Murdoch | da12d29 | 2016-06-02 14:46:10 +0100 | [diff] [blame] | 71 | double idle_time_in_ms, double scavenge_speed_in_bytes_per_ms, |
Ben Murdoch | 4a90d5f | 2016-03-22 12:00:34 +0000 | [diff] [blame] | 72 | size_t new_space_size) { |
| 73 | if (scavenge_speed_in_bytes_per_ms == 0) { |
| 74 | scavenge_speed_in_bytes_per_ms = kInitialScavengeSpeedInBytesPerMs; |
| 75 | } |
| 76 | return new_space_size <= idle_time_in_ms * scavenge_speed_in_bytes_per_ms; |
| 77 | } |
| 78 | |
| 79 | |
| 80 | void ScavengeJob::RescheduleIdleTask(Heap* heap) { |
| 81 | // Make sure that we don't reschedule more than one time. |
| 82 | // Otherwise, we might spam the scheduler with idle tasks. |
| 83 | if (!idle_task_rescheduled_) { |
| 84 | ScheduleIdleTask(heap); |
| 85 | idle_task_rescheduled_ = true; |
| 86 | } |
| 87 | } |
| 88 | |
| 89 | |
| 90 | void ScavengeJob::ScheduleIdleTaskIfNeeded(Heap* heap, int bytes_allocated) { |
| 91 | bytes_allocated_since_the_last_task_ += bytes_allocated; |
| 92 | if (bytes_allocated_since_the_last_task_ >= |
| 93 | static_cast<int>(kBytesAllocatedBeforeNextIdleTask)) { |
| 94 | ScheduleIdleTask(heap); |
| 95 | bytes_allocated_since_the_last_task_ = 0; |
| 96 | idle_task_rescheduled_ = false; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | |
| 101 | void ScavengeJob::ScheduleIdleTask(Heap* heap) { |
| 102 | if (!idle_task_pending_) { |
| 103 | v8::Isolate* isolate = reinterpret_cast<v8::Isolate*>(heap->isolate()); |
| 104 | if (V8::GetCurrentPlatform()->IdleTasksEnabled(isolate)) { |
| 105 | idle_task_pending_ = true; |
| 106 | auto task = new IdleTask(heap->isolate(), this); |
| 107 | V8::GetCurrentPlatform()->CallIdleOnForegroundThread(isolate, task); |
| 108 | } |
| 109 | } |
| 110 | } |
| 111 | } // namespace internal |
| 112 | } // namespace v8 |