xref: /aoo42x/main/cppuhelper/source/weak.cxx (revision cdf0e10c)

/*************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * Copyright 2000, 2010 Oracle and/or its affiliates.
 *
 * OpenOffice.org - a multi-platform office productivity suite
 *
 * This file is part of OpenOffice.org.
 *
 * OpenOffice.org is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License version 3
 * only, as published by the Free Software Foundation.
 *
 * OpenOffice.org is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License version 3 for more details
 * (a copy is included in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with OpenOffice.org.  If not, see
 * <http://www.openoffice.org/license.html>
 * for a copy of the LGPLv3 License.
 *
 ************************************************************************/

// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_cppuhelper.hxx"
#include <osl/mutex.hxx>
#ifndef _CPPU_WEAKAGG_HXX_
#include <cppuhelper/weakagg.hxx>
#endif
#ifndef _CPPU_HELPER_INTERFACECONTAINER_HXX_
#include <cppuhelper/interfacecontainer.hxx>
#endif
#include "cppuhelper/exc_hlp.hxx"

using namespace osl;
using namespace com::sun::star::uno;

/** */ //for docpp
namespace cppu
{

// due to static Reflection destruction from usr, ther must be a mutex leak (#73272#)
inline static Mutex & getWeakMutex() SAL_THROW( () )
{
	static Mutex * s_pMutex = 0;
	if (! s_pMutex)
		s_pMutex = new Mutex();
	return *s_pMutex;
}

//------------------------------------------------------------------------
//-- OWeakConnectionPoint ----------------------------------------------------
//------------------------------------------------------------------------
class OWeakConnectionPoint : public XAdapter
{
public:
	/**
		Hold the weak object without an acquire (only the pointer).
	 */
	OWeakConnectionPoint( OWeakObject* pObj ) SAL_THROW( () )
		: m_aRefCount( 0 )
		, m_pObject(pObj)
		, m_aReferences( getWeakMutex() )
		{}

	// XInterface
	Any SAL_CALL		queryInterface( const Type & rType ) throw(::com::sun::star::uno::RuntimeException);
	void SAL_CALL		acquire() throw();
	void SAL_CALL		release() throw();

	// XAdapter
    ::com::sun::star::uno::Reference< ::com::sun::star::uno::XInterface > SAL_CALL queryAdapted() throw(::com::sun::star::uno::RuntimeException);
    void SAL_CALL addReference( const ::com::sun::star::uno::Reference< ::com::sun::star::uno::XReference >& xRef ) throw(::com::sun::star::uno::RuntimeException);
    void SAL_CALL removeReference( const ::com::sun::star::uno::Reference< ::com::sun::star::uno::XReference >& xRef ) throw(::com::sun::star::uno::RuntimeException);

	/// Called from the weak object if the reference count goes to zero.
	void SAL_CALL dispose() throw(::com::sun::star::uno::RuntimeException);

private:
    OWeakConnectionPoint(OWeakConnectionPoint &); // not defined
    void operator =(OWeakConnectionPoint &); // not defined

    virtual ~OWeakConnectionPoint() {}

	/// The reference counter.
    oslInterlockedCount			m_aRefCount;
	/// The weak object
	OWeakObject* 				m_pObject;
	/// The container to hold the weak references
	OInterfaceContainerHelper	m_aReferences;
};

// XInterface
Any SAL_CALL OWeakConnectionPoint::queryInterface( const Type & rType )
	throw(com::sun::star::uno::RuntimeException)
{
	return ::cppu::queryInterface(
		rType, static_cast< XAdapter * >( this ), static_cast< XInterface * >( this ) );
}

// XInterface
void SAL_CALL OWeakConnectionPoint::acquire() throw()
{
	osl_incrementInterlockedCount( &m_aRefCount );
}

// XInterface
void SAL_CALL OWeakConnectionPoint::release() throw()
{
	if (! osl_decrementInterlockedCount( &m_aRefCount ))
		delete this;
}

void SAL_CALL OWeakConnectionPoint::dispose() throw(::com::sun::star::uno::RuntimeException)
{
    Any ex;
	OInterfaceIteratorHelper aIt( m_aReferences );
	while( aIt.hasMoreElements() )
    {
        try
        {
            ((XReference *)aIt.next())->dispose();
        }
        catch (com::sun::star::lang::DisposedException &) {}
        catch (RuntimeException &)
        {
            ex = cppu::getCaughtException();
        }
    }
    if (ex.hasValue())
    {
        cppu::throwException(ex);
    }
}

// XInterface
Reference< XInterface > SAL_CALL OWeakConnectionPoint::queryAdapted() throw(::com::sun::star::uno::RuntimeException)
{
	Reference< XInterface > ret;

	ClearableMutexGuard guard(getWeakMutex());

	if (m_pObject)
	{
		oslInterlockedCount n = osl_incrementInterlockedCount( &m_pObject->m_refCount );

		if (n > 1)
		{
			// The refence is incremented. The object cannot be destroyed.
			// Release the guard at the earliest point.
			guard.clear();
			// WeakObject has a (XInterface *) cast operator
			ret = *m_pObject;
			n = osl_decrementInterlockedCount( &m_pObject->m_refCount );
		}
		else
			// Another thread wait in the dispose method at the guard
			n = osl_decrementInterlockedCount( &m_pObject->m_refCount );
	}

	return ret;
}

// XInterface
void SAL_CALL OWeakConnectionPoint::addReference(const Reference< XReference >& rRef)
	throw(::com::sun::star::uno::RuntimeException)
{
	m_aReferences.addInterface( (const Reference< XInterface > &)rRef );
}

// XInterface
void SAL_CALL OWeakConnectionPoint::removeReference(const Reference< XReference >& rRef)
	throw(::com::sun::star::uno::RuntimeException)
{
	m_aReferences.removeInterface( (const Reference< XInterface > &)rRef );
}


//------------------------------------------------------------------------
//-- OWeakObject -------------------------------------------------------
//------------------------------------------------------------------------

#ifdef _MSC_VER
// Accidentally occurs in msvc mapfile = > had to be outlined.
OWeakObject::OWeakObject() SAL_THROW( () )
    : m_refCount( 0 ),
      m_pWeakConnectionPoint( 0 )
{
}
#endif

// XInterface
Any SAL_CALL OWeakObject::queryInterface( const Type & rType ) throw(::com::sun::star::uno::RuntimeException)
{
	return ::cppu::queryInterface(
		rType,
		static_cast< XWeak * >( this ), static_cast< XInterface * >( this ) );
}

// XInterface
void SAL_CALL OWeakObject::acquire() throw()
{
	osl_incrementInterlockedCount( &m_refCount );
}

// XInterface
void SAL_CALL OWeakObject::release() throw()
{
    if (osl_decrementInterlockedCount( &m_refCount ) == 0) {
        // notify/clear all weak-refs before object's dtor is executed
        // (which may check weak-refs to this object):
        disposeWeakConnectionPoint();
        // destroy object:
        delete this;
    }
}

void OWeakObject::disposeWeakConnectionPoint()
{
    OSL_PRECOND( m_refCount == 0, "OWeakObject::disposeWeakConnectionPoint: only to be called with a ref count of 0!" );
    if (m_pWeakConnectionPoint != 0) {
        OWeakConnectionPoint * const p = m_pWeakConnectionPoint;
        m_pWeakConnectionPoint = 0;
        try {
            p->dispose();
        }
        catch (RuntimeException const& exc) {
            OSL_ENSURE(
                false, OUStringToOString(
                    exc.Message, RTL_TEXTENCODING_ASCII_US ).getStr() );
            static_cast<void>(exc);
        }
        p->release();
    }
}

OWeakObject::~OWeakObject() SAL_THROW( (RuntimeException) )
{
}

// XWeak
Reference< XAdapter > SAL_CALL OWeakObject::queryAdapter()
	throw (::com::sun::star::uno::RuntimeException)
{
	if (!m_pWeakConnectionPoint)
	{
		// only acquire mutex if member is not created
		MutexGuard aGuard( getWeakMutex() );
		if( !m_pWeakConnectionPoint )
		{
			OWeakConnectionPoint * p = new OWeakConnectionPoint(this);
			p->acquire();
			m_pWeakConnectionPoint = p;
		}
	}

	return m_pWeakConnectionPoint;
}

//------------------------------------------------------------------------
//-- OWeakAggObject ----------------------------------------------------
//------------------------------------------------------------------------
OWeakAggObject::~OWeakAggObject() SAL_THROW( (RuntimeException) )
{
}

// XInterface
void OWeakAggObject::acquire() throw()
{
	Reference<XInterface > x( xDelegator );
	if (x.is())
		x->acquire();
	else
		OWeakObject::acquire();
}

// XInterface
void OWeakAggObject::release() throw()
{
	Reference<XInterface > x( xDelegator );
	if (x.is())
		x->release();
	else
		OWeakObject::release();
}

// XInterface
Any OWeakAggObject::queryInterface( const Type & rType ) throw(::com::sun::star::uno::RuntimeException)
{
	Reference< XInterface > x( xDelegator ); // harden ref
	return (x.is() ? x->queryInterface( rType ) : queryAggregation( rType ));

//  	// set rOut to zero, if failed
//  	if( !xDelegator.queryHardRef( aUik, rOut ) )
//  	{
//  		XInterfaceRef x;
//  		if( !xDelegator.queryHardRef( ((XInterface*)0)->getSmartUik(), x ) )
//  			// reference is not valid
//  			queryAggregation( aUik, rOut );
//  	}
//  	return rOut.is();
}

// XAggregation
Any OWeakAggObject::queryAggregation( const Type & rType ) throw(::com::sun::star::uno::RuntimeException)
{
	return ::cppu::queryInterface(
		rType,
		static_cast< XInterface * >( static_cast< OWeakObject * >( this ) ),
		static_cast< XAggregation * >( this ),
		static_cast< XWeak * >( this ) );
}

// XAggregation
void OWeakAggObject::setDelegator( const Reference<XInterface > & rDelegator ) throw(::com::sun::star::uno::RuntimeException)
{
	xDelegator = rDelegator;
}

}

/** */ //for docpp
namespace com
{
/** */ //for docpp
namespace sun
{
/** */ //for docpp
namespace star
{
/** */ //for docpp
namespace uno
{


//------------------------------------------------------------------------
//-- OWeakRefListener -----------------------------------------------------
//------------------------------------------------------------------------
class OWeakRefListener : public XReference
{
public:
	OWeakRefListener(const OWeakRefListener& rRef) SAL_THROW( () );
	OWeakRefListener(const Reference< XInterface >& xInt) SAL_THROW( () );
	virtual ~OWeakRefListener() SAL_THROW( () );

	// XInterface
    Any SAL_CALL queryInterface( const Type & rType ) throw(RuntimeException);
    void SAL_CALL acquire() throw();
    void SAL_CALL release() throw();

	// XReference
	void SAL_CALL 	dispose() throw(::com::sun::star::uno::RuntimeException);

	/// The reference counter.
    oslInterlockedCount			m_aRefCount;
	/// The connection point of the weak object
	Reference< XAdapter >		m_XWeakConnectionPoint;

private:
	OWeakRefListener& SAL_CALL operator=(const OWeakRefListener& rRef) SAL_THROW( () );
};

OWeakRefListener::OWeakRefListener(const OWeakRefListener& rRef) SAL_THROW( () )
	: com::sun::star::uno::XReference()
    , m_aRefCount( 1 )
{
    try
    {
	m_XWeakConnectionPoint = rRef.m_XWeakConnectionPoint;

	if (m_XWeakConnectionPoint.is())
    {
        m_XWeakConnectionPoint->addReference((XReference*)this);
    }
    }
    catch (RuntimeException &) { OSL_ASSERT( 0 ); } // assert here, but no unexpected()
    osl_decrementInterlockedCount( &m_aRefCount );
}

OWeakRefListener::OWeakRefListener(const Reference< XInterface >& xInt) SAL_THROW( () )
	: m_aRefCount( 1 )
{
    try
    {
	Reference< XWeak > xWeak( Reference< XWeak >::query( xInt ) );

	if (xWeak.is())
	{
		m_XWeakConnectionPoint = xWeak->queryAdapter();

		if (m_XWeakConnectionPoint.is())
		{
            m_XWeakConnectionPoint->addReference((XReference*)this);
		}
	}
    }
    catch (RuntimeException &) { OSL_ASSERT( 0 ); } // assert here, but no unexpected()
    osl_decrementInterlockedCount( &m_aRefCount );
}

OWeakRefListener::~OWeakRefListener() SAL_THROW( () )
{
    try
    {
	if (m_XWeakConnectionPoint.is())
    {
        acquire(); // dont die again
		m_XWeakConnectionPoint->removeReference((XReference*)this);
    }
    }
    catch (RuntimeException &) { OSL_ASSERT( 0 ); } // assert here, but no unexpected()
}

// XInterface
Any SAL_CALL OWeakRefListener::queryInterface( const Type & rType ) throw(RuntimeException)
{
	return ::cppu::queryInterface(
		rType, static_cast< XReference * >( this ), static_cast< XInterface * >( this ) );
}

// XInterface
void SAL_CALL OWeakRefListener::acquire() throw()
{
	osl_incrementInterlockedCount( &m_aRefCount );
}

// XInterface
void SAL_CALL OWeakRefListener::release() throw()
{
	if( ! osl_decrementInterlockedCount( &m_aRefCount ) )
		delete this;
}

void SAL_CALL OWeakRefListener::dispose()
	throw(::com::sun::star::uno::RuntimeException)
{
	Reference< XAdapter > xAdp;
	{
		MutexGuard guard(cppu::getWeakMutex());
		if( m_XWeakConnectionPoint.is() )
		{
			xAdp = m_XWeakConnectionPoint;
			m_XWeakConnectionPoint.clear();
		}
	}

	if( xAdp.is() )
		xAdp->removeReference((XReference*)this);
}

//------------------------------------------------------------------------
//-- WeakReferenceHelper ----------------------------------------------------------
//------------------------------------------------------------------------
WeakReferenceHelper::WeakReferenceHelper(const Reference< XInterface >& xInt) SAL_THROW( () )
	: m_pImpl( 0 )
{
	if (xInt.is())
	{
		m_pImpl = new OWeakRefListener(xInt);
		m_pImpl->acquire();
	}
}

WeakReferenceHelper::WeakReferenceHelper(const WeakReferenceHelper& rWeakRef) SAL_THROW( () )
	: m_pImpl( 0 )
{
	Reference< XInterface > xInt( rWeakRef.get() );
	if (xInt.is())
	{
		m_pImpl = new OWeakRefListener(xInt);
		m_pImpl->acquire();
	}
}

void WeakReferenceHelper::clear() SAL_THROW( () )
{
    try
    {
        if (m_pImpl)
        {
            if (m_pImpl->m_XWeakConnectionPoint.is())
            {
                m_pImpl->m_XWeakConnectionPoint->removeReference(
                        (XReference*)m_pImpl);
                m_pImpl->m_XWeakConnectionPoint.clear();
            }
            m_pImpl->release();
            m_pImpl = 0;
        }
    }
    catch (RuntimeException &) { OSL_ASSERT( 0 ); } // assert here, but no unexpected()
}

WeakReferenceHelper& WeakReferenceHelper::operator=(const WeakReferenceHelper& rWeakRef) SAL_THROW( () )
{
    if (this == &rWeakRef)
    {
        return *this;
    }
    Reference< XInterface > xInt( rWeakRef.get() );
    return operator = ( xInt );
}

WeakReferenceHelper & SAL_CALL
WeakReferenceHelper::operator= (const Reference< XInterface > & xInt)
SAL_THROW( () )
{
    try
    {
        clear();
		if (xInt.is())
		{
			m_pImpl = new OWeakRefListener(xInt);
			m_pImpl->acquire();
		}
    }
    catch (RuntimeException &) { OSL_ASSERT( 0 ); } // assert here, but no unexpected()
    return *this;
}

WeakReferenceHelper::~WeakReferenceHelper() SAL_THROW( () )
{
    clear();
}

Reference< XInterface > WeakReferenceHelper::get() const SAL_THROW( () )
{
    try
    {
	Reference< XAdapter > xAdp;
	{
		MutexGuard guard(cppu::getWeakMutex());
		if( m_pImpl && m_pImpl->m_XWeakConnectionPoint.is() )
			xAdp = m_pImpl->m_XWeakConnectionPoint;
	}

	if (xAdp.is())
		return xAdp->queryAdapted();
    }
    catch (RuntimeException &) { OSL_ASSERT( 0 ); } // assert here, but no unexpected()

	return Reference< XInterface >();
}

}
}
}
}