microtask.h

// Copyright 2018 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_OBJECTS_MICROTASK_H_
#define V8_OBJECTS_MICROTASK_H_

#include "src/objects.h"

// Has to be the last include (doesn't have include guards):
#include "src/objects/object-macros.h"

namespace v8 {
namespace internal {

// Abstract base class for all microtasks that can be scheduled on the
// microtask queue. This class merely serves the purpose of a marker
// interface.
class Microtask : public Struct {
 public:
  // Dispatched behavior.
  DECL_CAST(Microtask)
  DECL_VERIFIER(Microtask)

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(Microtask);
};

// A CallbackTask is a special Microtask that allows us to schedule
// C++ microtask callbacks on the microtask queue. This is heavily
// used by Blink for example.
class CallbackTask : public Microtask {
 public:
  DECL_ACCESSORS(callback, Foreign)
  DECL_ACCESSORS(data, Foreign)

  static const int kCallbackOffset = Microtask::kHeaderSize;
  static const int kDataOffset = kCallbackOffset + kPointerSize;
  static const int kSize = kDataOffset + kPointerSize;

  // Dispatched behavior.
  DECL_CAST(CallbackTask)
  DECL_PRINTER(CallbackTask)
  DECL_VERIFIER(CallbackTask)

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(CallbackTask)
};

// A CallableTask is a special (internal) Microtask that allows us to
// schedule arbitrary callables on the microtask queue. We use this
// for various tests of the microtask queue.
class CallableTask : public Microtask {
 public:
  DECL_ACCESSORS(callable, JSReceiver)
  DECL_ACCESSORS2(context, Context)

  static const int kCallableOffset = Microtask::kHeaderSize;
  static const int kContextOffset = kCallableOffset + kPointerSize;
  static const int kSize = kContextOffset + kPointerSize;

  // Dispatched behavior.
  DECL_CAST(CallableTask)
  DECL_PRINTER(CallableTask)
  DECL_VERIFIER(CallableTask)
  void BriefPrintDetails(std::ostream& os);

 private:
  DISALLOW_IMPLICIT_CONSTRUCTORS(CallableTask);
};

}  // namespace internal
}  // namespace v8

#include "src/objects/object-macros-undef.h"

#endif  // V8_OBJECTS_MICROTASK_H_