/*
* Copyright (C) 2008 Apple Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef ActiveDOMObject_h
#define ActiveDOMObject_h
#include "core/dom/ContextLifecycleObserver.h"
#include "wtf/Assertions.h"
#include "wtf/Forward.h"
namespace WebCore {
class ActiveDOMObject : public ContextLifecycleObserver {
public:
ActiveDOMObject(ExecutionContext*);
// suspendIfNeeded() should be called exactly once after object construction to synchronize
// the suspend state with that in ExecutionContext.
void suspendIfNeeded();
#if !ASSERT_DISABLED
bool suspendIfNeededCalled() const { return m_suspendIfNeededCalled; }
#endif
// Should return true if there's any pending asynchronous activity, and so
// this object must not be garbage collected.
//
// Default implementation is that it returns true iff
// m_pendingActivityCount is non-zero.
virtual bool hasPendingActivity() const;
// These methods have an empty default implementation so that subclasses
// which don't need special treatment can skip implementation.
virtual void suspend();
virtual void resume();
// willStop is called when stop() for the owner worker is called. It's not
// called if the owner is a Document. It's ok to post a task to the context.
virtual void willStop();
virtual void stop();
void didMoveToNewExecutionContext(ExecutionContext*);
protected:
virtual ~ActiveDOMObject();
template<class T> void setPendingActivity(T* thisObject)
{
ASSERT(thisObject == this);
thisObject->ref();
m_pendingActivityCount++;
}
template<class T> void unsetPendingActivity(T* thisObject)
{
ASSERT(m_pendingActivityCount > 0);
--m_pendingActivityCount;
thisObject->deref();
}
private:
unsigned m_pendingActivityCount;
#if !ASSERT_DISABLED
bool m_suspendIfNeededCalled;
#endif
};
} // namespace WebCore
#endif // ActiveDOMObject_h