gecko-dev/xpcom/base/nsMemoryImpl.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 nsMemoryImpl_h__
#define nsMemoryImpl_h__

#include "mozilla/Atomics.h"

#include "nsIMemory.h"
#include "nsIRunnable.h"

// nsMemoryImpl is a static object. We can do this because it doesn't have
// a constructor/destructor or any instance members. Please don't add
// instance member variables, only static member variables.

class nsMemoryImpl : public nsIMemory {
 public:
  // We don't use the generic macros because we are a special static object
  NS_IMETHOD QueryInterface(REFNSIID aIID, void** aResult) override;
  NS_IMETHOD_(MozExternalRefCountType) AddRef(void) override { return 1; }
  NS_IMETHOD_(MozExternalRefCountType) Release(void) override { return 1; }

  NS_DECL_NSIMEMORY

  static nsresult Create(nsISupports* aOuter, const nsIID& aIID,
                         void** aResult);

  nsresult FlushMemory(const char16_t* aReason, bool aImmediate);
  void RunFlushers(const char16_t* aReason);

 protected:
  struct FlushEvent : public nsIRunnable {
    constexpr FlushEvent() : mReason(nullptr) {}
    NS_DECL_ISUPPORTS_INHERITED
    NS_DECL_NSIRUNNABLE
    const char16_t* mReason;
  };

  static mozilla::Atomic<bool> sIsFlushing;
  static FlushEvent sFlushEvent;
  static PRIntervalTime sLastFlushTime;
};

#endif  // nsMemoryImpl_h__