blob: 3ab07a607316ee6d6114d7668b731ae378c81bf4 [file] [log] [blame]
// Copyright 2017 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include <memory>
#include "include/v8-platform.h"
#include "src/base/atomic-utils.h"
#include "src/base/platform/condition-variable.h"
#include "src/base/platform/mutex.h"
#include "src/heap/marking-visitor.h"
#include "src/heap/marking-worklist.h"
#include "src/heap/memory-measurement.h"
#include "src/heap/slot-set.h"
#include "src/heap/spaces.h"
#include "src/heap/worklist.h"
#include "src/init/v8.h"
#include "src/tasks/cancelable-task.h"
#include "src/utils/allocation.h"
#include "src/utils/utils.h"
namespace v8 {
namespace internal {
class Heap;
class Isolate;
class MajorNonAtomicMarkingState;
class MemoryChunk;
struct WeakObjects;
struct MemoryChunkData {
intptr_t live_bytes;
std::unique_ptr<TypedSlots> typed_slots;
using MemoryChunkDataMap =
std::unordered_map<MemoryChunk*, MemoryChunkData, MemoryChunk::Hasher>;
class V8_EXPORT_PRIVATE ConcurrentMarking {
// When the scope is entered, the concurrent marking tasks
// are preempted and are not looking at the heap objects, concurrent marking
// is resumed when the scope is exited.
class PauseScope {
explicit PauseScope(ConcurrentMarking* concurrent_marking);
ConcurrentMarking* const concurrent_marking_;
const bool resume_on_exit_;
enum class StopRequest {
// Preempt ongoing tasks ASAP (and cancel unstarted tasks).
// Wait for ongoing tasks to complete (and cancels unstarted tasks).
// Wait for all scheduled tasks to complete (only use this in tests that
// control the full stack -- otherwise tasks cancelled by the platform can
// make this call hang).
// TODO(gab): The only thing that prevents this being above 7 is
// Worklist::kMaxNumTasks being maxed at 8 (concurrent marking doesn't use
// task 0, reserved for the main thread).
static constexpr int kMaxTasks = 7;
ConcurrentMarking(Heap* heap,
MarkingWorklistsHolder* marking_worklists_holder,
WeakObjects* weak_objects);
// Schedules asynchronous tasks to perform concurrent marking. Objects in the
// heap should not be moved while these are active (can be stopped safely via
// Stop() or PauseScope).
void ScheduleTasks();
// Stops concurrent marking per |stop_request|'s semantics. Returns true
// if concurrent marking was in progress, false otherwise.
bool Stop(StopRequest stop_request);
void RescheduleTasksIfNeeded();
// Flushes native context sizes to the given table of the main thread.
void FlushNativeContexts(NativeContextStats* main_stats);
// Flushes memory chunk data using the given marking state.
void FlushMemoryChunkData(MajorNonAtomicMarkingState* marking_state);
// This function is called for a new space page that was cleared after
// scavenge and is going to be re-used.
void ClearMemoryChunkData(MemoryChunk* chunk);
// Checks if all threads are stopped.
bool IsStopped();
size_t TotalMarkedBytes();
void set_ephemeron_marked(bool ephemeron_marked) {;
bool ephemeron_marked() { return ephemeron_marked_.load(); }
struct TaskState {
// The main thread sets this flag to true when it wants the concurrent
// marker to give up the worker thread.
std::atomic<bool> preemption_request;
size_t marked_bytes = 0;
unsigned mark_compact_epoch;
bool is_forced_gc;
MemoryChunkDataMap memory_chunk_data;
NativeContextInferrer native_context_inferrer;
NativeContextStats native_context_stats;
char cache_line_padding[64];
class Task;
void Run(int task_id, TaskState* task_state);
Heap* const heap_;
MarkingWorklistsHolder* const marking_worklists_holder_;
WeakObjects* const weak_objects_;
TaskState task_state_[kMaxTasks + 1];
std::atomic<size_t> total_marked_bytes_{0};
std::atomic<bool> ephemeron_marked_{false};
base::Mutex pending_lock_;
base::ConditionVariable pending_condition_;
int pending_task_count_ = 0;
bool is_pending_[kMaxTasks + 1] = {};
CancelableTaskManager::Id cancelable_id_[kMaxTasks + 1] = {};
int total_task_count_ = 0;
} // namespace internal
} // namespace v8