Allocate semaphore of page parallel job on heap.

src/heap/page-parallel-job.h

 // 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"
@@ skipping 20 matching lines @@
 //                                        MemoryChunk* page,
 //                                        PerPageData page_data)
 template <typename JobTraits>
 class PageParallelJob {
  public:
   PageParallelJob(Heap* heap, CancelableTaskManager* cancelable_task_manager)
       : heap_(heap),
         cancelable_task_manager_(cancelable_task_manager),
         items_(nullptr),
         num_items_(0),
-        pending_tasks_(0) {}
+        num_tasks_(0),
+        pending_tasks_(new base::Semaphore(0)) {}
 
   ~PageParallelJob() {
     Item* item = items_;
     while (item != nullptr) {
       Item* next = item->next;
       delete item;
       item = next;
     }
+    delete pending_tasks_;
   }
 
   void AddPage(MemoryChunk* chunk, typename JobTraits::PerPageData data) {
     Item* item = new Item(chunk, data, items_);
     items_ = item;
     ++num_items_;
   }
 
   int NumberOfPages() { return num_items_; }
 
@@ skipping 14 matching lines @@
             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));
+                            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])) {
-        pending_tasks_.Wait();
+        pending_tasks_->Wait();
       }
     }
     if (JobTraits::NeedSequentialFinalization) {
       Item* item = items_;
       while (item != nullptr) {
         bool success = (item->state.Value() == kFinished);
         JobTraits::FinalizePageSequentially(heap_, item->chunk, success,
                                             item->data);
         item = item->next;
       }
@@ skipping 59 matching lines @@
     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_;
+  base::Semaphore* pending_tasks_;
   DISALLOW_COPY_AND_ASSIGN(PageParallelJob);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_PAGE_PARALLEL_JOB_