Worker: Introduce per-global-scope task scheduler

third_party/WebKit/Source/core/workers/WorkerBackingThread.h

 // Copyright 2016 The Chromium 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 WorkerBackingThread_h
 #define WorkerBackingThread_h
 
 #include <memory>
 
 #include "core/CoreExport.h"
 #include "platform/heap/ThreadState.h"
 #include "platform/wtf/Forward.h"
 #include "platform/wtf/PtrUtil.h"
 #include "platform/wtf/ThreadingPrimitives.h"
 #include "v8/include/v8.h"
 
 namespace blink {
 
+namespace scheduler {
+class WorkerGlobalScopeScheduler;
+}  // namespace scheduler
+
 class WebThread;
 class WebThreadSupportingGC;
 
 // WorkerBackingThread represents a WebThread with Oilpan and V8 potentially
 // shared by multiple WebWorker scripts. A WebWorker needs to call initialize()
 // to using V8 and Oilpan functionalities, and call shutdown() when the script
 // no longer needs the thread.
 // A WorkerBackingThread represents a WebThread while a WorkerThread corresponds
 // to a web worker. There is one-to-one correspondence between WorkerThread and
 // WorkerGlobalScope, but multiple WorkerThreads (i.e., multiple
@@ skipping 18 matching lines @@
 
   ~WorkerBackingThread();
 
   // initialize() and shutdown() attaches and detaches Oilpan and V8 to / from
   // the caller worker script, respectively. A worker script must not call
   // any function after calling shutdown().
   // They should be called from |this| thread.
   void Initialize();
   void Shutdown();
 
+  std::unique_ptr<scheduler::WorkerGlobalScopeScheduler>
+  CreateGlobalScopeScheduler();

[haraken, 2017/04/17 14:49:52]

Shall we inline the method in WorkerThread::InitializeSchedulerOnWorkerThread?

[nhiroki, 2017/04/18 05:34:38]

Done.

+
   WebThreadSupportingGC& BackingThread() {
     DCHECK(backing_thread_);
     return *backing_thread_;
   }
 
   v8::Isolate* GetIsolate() { return isolate_; }
 
   static void MemoryPressureNotificationToWorkerThreadIsolates(
       v8::MemoryPressureLevel);
 
   static void SetRAILModeOnWorkerThreadIsolates(v8::RAILMode);
 
  private:
   WorkerBackingThread(const char* name, bool should_call_gc_on_shutdown);
   WorkerBackingThread(WebThread*, bool should_call_gc_on_s_hutdown);
 
   std::unique_ptr<WebThreadSupportingGC> backing_thread_;
   v8::Isolate* isolate_ = nullptr;
   bool is_owning_thread_;
   bool should_call_gc_on_shutdown_;
 };
 
 }  // namespace blink
 
 #endif  // WorkerBackingThread_h