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Diffstat (limited to 'deps/v8/src/heap/page-parallel-job.h')
| -rw-r--r-- | deps/v8/src/heap/page-parallel-job.h | 180 |
1 files changed, 0 insertions, 180 deletions
diff --git a/deps/v8/src/heap/page-parallel-job.h b/deps/v8/src/heap/page-parallel-job.h deleted file mode 100644 index 939bdb3b3b..0000000000 --- a/deps/v8/src/heap/page-parallel-job.h +++ /dev/null @@ -1,180 +0,0 @@ -// Copyright 2016 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. - -#ifndef V8_HEAP_PAGE_PARALLEL_JOB_ -#define V8_HEAP_PAGE_PARALLEL_JOB_ - -#include "src/allocation.h" -#include "src/cancelable-task.h" -#include "src/utils.h" -#include "src/v8.h" - -namespace v8 { -namespace internal { - -class Heap; -class Isolate; - -// This class manages background tasks that process set of pages in parallel. -// The JobTraits class needs to define: -// - PerPageData type - state associated with each page. -// - PerTaskData type - state associated with each task. -// - static void ProcessPageInParallel(Heap* heap, -// PerTaskData task_data, -// MemoryChunk* page, -// PerPageData page_data) -template <typename JobTraits> -class PageParallelJob { - public: - // PageParallelJob cannot dynamically create a semaphore because of a bug in - // glibc. See http://crbug.com/609249 and - // https://sourceware.org/bugzilla/show_bug.cgi?id=12674. - // The caller must provide a semaphore with value 0 and ensure that - // the lifetime of the semaphore is the same as the lifetime of the Isolate. - // It is guaranteed that the semaphore value will be 0 after Run() call. - PageParallelJob(Heap* heap, CancelableTaskManager* cancelable_task_manager, - base::Semaphore* semaphore) - : heap_(heap), - cancelable_task_manager_(cancelable_task_manager), - items_(nullptr), - num_items_(0), - num_tasks_(0), - pending_tasks_(semaphore) {} - - ~PageParallelJob() { - Item* item = items_; - while (item != nullptr) { - Item* next = item->next; - delete item; - item = next; - } - } - - void AddPage(MemoryChunk* chunk, typename JobTraits::PerPageData data) { - Item* item = new Item(chunk, data, items_); - items_ = item; - ++num_items_; - } - - int NumberOfPages() const { return num_items_; } - - // Returns the number of tasks that were spawned when running the job. - int NumberOfTasks() const { return num_tasks_; } - - // Runs the given number of tasks in parallel and processes the previously - // added pages. This function blocks until all tasks finish. - // The callback takes the index of a task and returns data for that task. - template <typename Callback> - void Run(int num_tasks, Callback per_task_data_callback) { - if (num_items_ == 0) return; - DCHECK_GE(num_tasks, 1); - CancelableTaskManager::Id task_ids[kMaxNumberOfTasks]; - const int max_num_tasks = Min( - kMaxNumberOfTasks, - static_cast<int>( - V8::GetCurrentPlatform()->NumberOfAvailableBackgroundThreads())); - num_tasks_ = Max(1, Min(num_tasks, max_num_tasks)); - int items_per_task = (num_items_ + num_tasks_ - 1) / num_tasks_; - int start_index = 0; - Task* main_task = nullptr; - for (int i = 0; i < num_tasks_; i++, start_index += items_per_task) { - if (start_index >= num_items_) { - start_index -= num_items_; - } - Task* task = new Task(heap_, items_, num_items_, start_index, - pending_tasks_, per_task_data_callback(i)); - task_ids[i] = task->id(); - if (i > 0) { - V8::GetCurrentPlatform()->CallOnBackgroundThread( - task, v8::Platform::kShortRunningTask); - } else { - main_task = task; - } - } - // Contribute on main thread. - main_task->Run(); - delete main_task; - // Wait for background tasks. - for (int i = 0; i < num_tasks_; i++) { - if (cancelable_task_manager_->TryAbort(task_ids[i]) != - CancelableTaskManager::kTaskAborted) { - pending_tasks_->Wait(); - } - } - } - - private: - static const int kMaxNumberOfTasks = 32; - - enum ProcessingState { kAvailable, kProcessing, kFinished }; - - struct Item : public Malloced { - Item(MemoryChunk* chunk, typename JobTraits::PerPageData data, Item* next) - : chunk(chunk), state(kAvailable), data(data), next(next) {} - MemoryChunk* chunk; - base::AtomicValue<ProcessingState> state; - typename JobTraits::PerPageData data; - Item* next; - }; - - class Task : public CancelableTask { - public: - Task(Heap* heap, Item* items, int num_items, int start_index, - base::Semaphore* on_finish, typename JobTraits::PerTaskData data) - : CancelableTask(heap->isolate()), - heap_(heap), - items_(items), - num_items_(num_items), - start_index_(start_index), - on_finish_(on_finish), - data_(data) {} - - virtual ~Task() {} - - private: - // v8::internal::CancelableTask overrides. - void RunInternal() override { - // Each task starts at a different index to improve parallelization. - Item* current = items_; - int skip = start_index_; - while (skip-- > 0) { - current = current->next; - } - for (int i = 0; i < num_items_; i++) { - if (current->state.TrySetValue(kAvailable, kProcessing)) { - JobTraits::ProcessPageInParallel(heap_, data_, current->chunk, - current->data); - current->state.SetValue(kFinished); - } - current = current->next; - // Wrap around if needed. - if (current == nullptr) { - current = items_; - } - } - on_finish_->Signal(); - } - - Heap* heap_; - Item* items_; - int num_items_; - int start_index_; - base::Semaphore* on_finish_; - typename JobTraits::PerTaskData data_; - DISALLOW_COPY_AND_ASSIGN(Task); - }; - - Heap* heap_; - CancelableTaskManager* cancelable_task_manager_; - Item* items_; - int num_items_; - int num_tasks_; - base::Semaphore* pending_tasks_; - DISALLOW_COPY_AND_ASSIGN(PageParallelJob); -}; - -} // namespace internal -} // namespace v8 - -#endif // V8_HEAP_PAGE_PARALLEL_JOB_ |