gecko-dev/dom/cache/CacheChild.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef mozilla_dom_cache_CacheChild_h
#define mozilla_dom_cache_CacheChild_h

#include "mozilla/dom/cache/ActorChild.h"
#include "mozilla/dom/cache/PCacheChild.h"

class nsIAsyncInputStream;
class nsIGlobalObject;

namespace mozilla {
namespace dom {

class Promise;

namespace cache {

class Cache;
class CacheOpArgs;

class CacheChild final : public PCacheChild
                       , public ActorChild
{
public:
  class MOZ_RAII AutoLock final
  {
    CacheChild* mActor;

  public:
    explicit AutoLock(CacheChild* aActor)
      : mActor(aActor)
    {
      MOZ_ASSERT(mActor);
      mActor->Lock();
    }

    ~AutoLock()
    {
      mActor->Unlock();
    }
  };

  CacheChild();
  ~CacheChild();

  void SetListener(Cache* aListener);

  // Must be called by the associated Cache listener in its DestroyInternal()
  // method.  Also, Cache must call StartDestroyFromListener() on the actor in
  // its destructor to trigger ActorDestroy() if it has not been called yet.
  void ClearListener();

  void
  ExecuteOp(nsIGlobalObject* aGlobal, Promise* aPromise,
            nsISupports* aParent, const CacheOpArgs& aArgs);

  // Our parent Listener object has gone out of scope and is being destroyed.
  void StartDestroyFromListener();

private:
  // ActorChild methods

  // WorkerHolder is trying to destroy due to worker shutdown.
  virtual void StartDestroy() override;

  // PCacheChild methods
  virtual void
  ActorDestroy(ActorDestroyReason aReason) override;

  virtual PCacheOpChild*
  AllocPCacheOpChild(const CacheOpArgs& aOpArgs) override;

  virtual bool
  DeallocPCacheOpChild(PCacheOpChild* aActor) override;

  // utility methods
  void
  NoteDeletedActor();

  void
  MaybeFlushDelayedDestroy();

  // Methods used to temporarily force the actor alive.  Only called from
  // AutoLock.
  void
  Lock();

  void
  Unlock();

  // Use a weak ref so actor does not hold DOM object alive past content use.
  // The Cache object must call ClearListener() to null this before its
  // destroyed.
  Cache* MOZ_NON_OWNING_REF mListener;
  uint32_t mNumChildActors;
  bool mDelayedDestroy;
  bool mLocked;

  NS_DECL_OWNINGTHREAD
};

} // namespace cache
} // namespace dom
} // namespace mozilla

#endif // mozilla_dom_cache_CacheChild_h