gecko-dev/image/ShutdownTracker.h

47 lines
1.4 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* 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/. */
/**
* ShutdownTracker is an imagelib-global service that allows callers to check
* whether shutdown has started.
*/
#ifndef mozilla_image_ShutdownTracker_h
#define mozilla_image_ShutdownTracker_h
namespace mozilla {
namespace image {
/**
* ShutdownTracker is an imagelib-global service that allows callers to check
* whether shutdown has started. It exists to avoid the need for registering
* many 'xpcom-will-shutdown' notification observers on short-lived objects,
* which would have an unnecessary performance cost.
*/
struct ShutdownTracker
{
/**
* Initialize static data. Called during imagelib module initialization.
*/
static void Initialize();
/**
* Check whether shutdown has started. Callers can use this to check whether
* it's safe to access XPCOM services; if shutdown has started, such calls
* must be avoided.
*
* @return true if shutdown has already started.
*/
static bool ShutdownHasStarted();
private:
virtual ~ShutdownTracker() = 0; // Forbid instantiation.
};
} // namespace image
} // namespace mozilla
#endif // mozilla_image_ShutdownTracker_h