source/tools/LifeTime.cxx

/**************************************************************
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 *************************************************************/


// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_chart2.hxx"
#include "LifeTime.hxx"
#include "macros.hxx"
#include <osl/diagnose.h>

#include <com/sun/star/util/XModifyListener.hpp>
#include <com/sun/star/util/XCloseListener.hpp>

using namespace ::com::sun::star;

namespace apphelper
{
//--------------------------

LifeTimeManager::LifeTimeManager( lang::XComponent* pComponent, sal_Bool bLongLastingCallsCancelable )
    : m_aListenerContainer( m_aAccessMutex )
    , m_pComponent(pComponent)
    , m_bLongLastingCallsCancelable(bLongLastingCallsCancelable)
{
    impl_init();
}

void LifeTimeManager::impl_init()
{
    m_bDisposed = sal_False;
    m_bInDispose = sal_False;
    m_nAccessCount = 0;
    m_nLongLastingCallCount = 0;
    m_aNoAccessCountCondition.set();
    m_aNoLongLastingCallCountCondition.set();
}

LifeTimeManager::~LifeTimeManager()
{
}

bool LifeTimeManager::impl_isDisposed( bool bAssert )
{
    if( m_bDisposed || m_bInDispose )
    {
        if( bAssert )
        {
            OSL_ENSURE( sal_False, "This component is already disposed " );
            (void)(bAssert);
        }
        return sal_True;
    }
    return sal_False;
}
            sal_Bool LifeTimeManager
::impl_canStartApiCall()
{
    if( impl_isDisposed() )
        return sal_False; //behave passive if already disposed

    //mutex is acquired
    return sal_True;
}

    void LifeTimeManager
::impl_registerApiCall(sal_Bool bLongLastingCall)
{
    //only allowed if not disposed
    //do not acquire the mutex here because it will be acquired already
    m_nAccessCount++;
    if(m_nAccessCount==1)
        //@todo? is it ok to wake some threads here while we have acquired the mutex?
        m_aNoAccessCountCondition.reset();

    if(bLongLastingCall)
        m_nLongLastingCallCount++;
    if(m_nLongLastingCallCount==1)
        m_aNoLongLastingCallCountCondition.reset();
}
    void LifeTimeManager
::impl_unregisterApiCall(sal_Bool bLongLastingCall)
{
    //Mutex needs to be acquired exactly ones
    //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()

    OSL_ENSURE( m_nAccessCount>0, "access count mismatch" );
    m_nAccessCount--;
    if(bLongLastingCall)
        m_nLongLastingCallCount--;
    if( m_nLongLastingCallCount==0 )
    {
        m_aNoLongLastingCallCountCondition.set();
    }
    if( m_nAccessCount== 0)
    {
        m_aNoAccessCountCondition.set();
        impl_apiCallCountReachedNull();

    }
}

        sal_Bool LifeTimeManager
::dispose() throw(uno::RuntimeException)
{
    //hold no mutex
    {
        osl::Guard< osl::Mutex > aGuard( m_aAccessMutex );

        if( m_bDisposed || m_bInDispose )
        {
            OSL_TRACE( "This component is already disposed " );
            return sal_False; //behave passive if already disposed
        }

        m_bInDispose = true;
        //adding any listener is not allowed anymore
        //new calls will not be accepted
        //still running calls have the freedom to finish their work without crash
    }
    //no mutex is acquired

    //--do the disposing of listeners after calling this method
    {
        uno::Reference< lang::XComponent > xComponent =
            uno::Reference< lang::XComponent >(m_pComponent);;
        if(xComponent.is())
        {
            // notify XCLoseListeners
            lang::EventObject aEvent( xComponent );
            m_aListenerContainer.disposeAndClear( aEvent );
        }
    }

    //no mutex is acquired
    {
        osl::ClearableGuard< osl::Mutex > aGuard( m_aAccessMutex );
        OSL_ENSURE( !m_bDisposed, "dispose was called already" );
        m_bDisposed = sal_True;
        aGuard.clear();
    }
    //no mutex is acquired

    //wait until all still running calls have finished
    //the accessCount cannot grow anymore, because all calls will return after checking m_bDisposed
    m_aNoAccessCountCondition.wait();

    //we are the only ones working on our data now

    return sal_True;
    //--release all resources and references after calling this method successful
}

//-----------------------------------------------------------------

CloseableLifeTimeManager::CloseableLifeTimeManager( ::com::sun::star::util::XCloseable* pCloseable
        , ::com::sun::star::lang::XComponent* pComponent
        , sal_Bool bLongLastingCallsCancelable )
        : LifeTimeManager( pComponent, bLongLastingCallsCancelable )
        , m_pCloseable(pCloseable)
{
    impl_init();
}

CloseableLifeTimeManager::~CloseableLifeTimeManager()
{
}

bool CloseableLifeTimeManager::impl_isDisposedOrClosed( bool bAssert )
{
    if( impl_isDisposed( bAssert ) )
        return sal_True;

    if( m_bClosed )
    {
        if( bAssert )
        {
            OSL_ENSURE( sal_False, "This object is already closed" );
            (void)(bAssert);//avoid warnings
        }
        return sal_True;
    }
    return sal_False;
}

        sal_Bool CloseableLifeTimeManager
::g_close_startTryClose(sal_Bool bDeliverOwnership)
    throw ( uno::Exception )
{
    //no mutex is allowed to be acquired
    {
        osl::ResettableGuard< osl::Mutex > aGuard( m_aAccessMutex );
        if( impl_isDisposedOrClosed(false) )
            return sal_False;

        //Mutex needs to be acquired exactly ones; will be released inbetween
        if( !impl_canStartApiCall() )
            return sal_False;
        //mutex is acquired

        //not closed already -> we try to close again
        m_bInTryClose = sal_True;
        m_aEndTryClosingCondition.reset();

        impl_registerApiCall(sal_False);
    }

    //------------------------------------------------
    //no mutex is acquired

    //only remove listener calls will be worked on until end of tryclose
    //all other new calls will wait till end of try close // @todo? is that really ok

    //?? still running calls have the freedom to finish their work without crash

    try
    {
        uno::Reference< util::XCloseable > xCloseable =
            uno::Reference< util::XCloseable >(m_pCloseable);;
        if(xCloseable.is())
        {
            //--call queryClosing on all registered close listeners
            ::cppu::OInterfaceContainerHelper* pIC = m_aListenerContainer.getContainer(
                        ::getCppuType((const uno::Reference< util::XCloseListener >*)0) );;
            if( pIC )
            {
                //lang::EventObject aEvent( static_cast< util::XCloseable*>(xCloseable) );
                lang::EventObject aEvent( xCloseable );
                ::cppu::OInterfaceIteratorHelper aIt( *pIC );
                while( aIt.hasMoreElements() )
                {
                    uno::Reference< util::XCloseListener > xCloseListener( aIt.next(), uno::UNO_QUERY );
                    if(xCloseListener.is())
                        xCloseListener->queryClosing( aEvent, bDeliverOwnership );
                }
            }
        }
    }
    catch( uno::Exception& ex )
    {
        //no mutex is acquired
        g_close_endTryClose(bDeliverOwnership, sal_False);
        (void)(ex);
        throw;
    }
    return sal_True;
}

    void CloseableLifeTimeManager
::g_close_endTryClose(sal_Bool bDeliverOwnership, sal_Bool /* bMyVeto */ )
{
    //this method is called, if the try to close was not successfull
    osl::Guard< osl::Mutex > aGuard( m_aAccessMutex );
    impl_setOwnership( bDeliverOwnership, sal_False );

    m_bInTryClose = sal_False;
    m_aEndTryClosingCondition.set();

    //Mutex needs to be acquired exactly ones
    //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()
    impl_unregisterApiCall(sal_False);
}

    sal_Bool CloseableLifeTimeManager
::g_close_isNeedToCancelLongLastingCalls( sal_Bool bDeliverOwnership, util::CloseVetoException& ex )
    throw ( util::CloseVetoException )
{
    //this method is called when no closelistener has had a veto during queryclosing
    //the method returns false, if nothing stands against closing anymore
    //it returns true, if some longlasting calls are running, which might be cancelled
    //it throws the given exception, if long calls are running but not cancelable

    osl::Guard< osl::Mutex > aGuard( m_aAccessMutex );
    //this count cannot grow after try of close has started, because we wait in all those methods for end of try closing
    if( !m_nLongLastingCallCount )
        return sal_False;

    if(m_bLongLastingCallsCancelable)
        return sal_True;

    impl_setOwnership( bDeliverOwnership, sal_True );

    m_bInTryClose = sal_False;
    m_aEndTryClosingCondition.set();

    //Mutex needs to be acquired exactly ones
    //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()
    impl_unregisterApiCall(sal_False);

    throw ex;
}

    void CloseableLifeTimeManager
::g_close_endTryClose_doClose()
{
    //this method is called, if the try to close was successfull
    osl::ResettableGuard< osl::Mutex > aGuard( m_aAccessMutex );

    m_bInTryClose       = sal_False;
    m_aEndTryClosingCondition.set();

    //Mutex needs to be acquired exactly ones
    //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()
    impl_unregisterApiCall(sal_False);
    impl_doClose();
}

    void CloseableLifeTimeManager
::impl_setOwnership( sal_Bool bDeliverOwnership, sal_Bool bMyVeto )
{
    m_bOwnership            = bDeliverOwnership && bMyVeto;
    m_bOwnershipIsWellKnown = sal_True;
}
    sal_Bool CloseableLifeTimeManager
::impl_shouldCloseAtNextChance()
{
    return m_bOwnership;
}

    void CloseableLifeTimeManager
::impl_apiCallCountReachedNull()
{
    //Mutex needs to be acquired exactly ones
    //mutex will be released inbetween in impl_doClose()
    if( m_pCloseable && impl_shouldCloseAtNextChance() )
        impl_doClose();
}

    void CloseableLifeTimeManager
::impl_doClose()
{
    //Mutex needs to be acquired exactly ones before calling impl_doClose()

    if(m_bClosed)
        return; //behave as passive as possible, if disposed or closed already
    if( m_bDisposed || m_bInDispose )
        return; //behave as passive as possible, if disposed or closed already

    //--------
    m_bClosed = sal_True;

    NegativeGuard< osl::Mutex > aNegativeGuard( m_aAccessMutex );
    //mutex is not acquired, mutex will be reacquired at the end of this method automatically

    uno::Reference< util::XCloseable > xCloseable=NULL;
    try
    {
        xCloseable = uno::Reference< util::XCloseable >(m_pCloseable);;
        if(xCloseable.is())
        {
            //--call notifyClosing on all registered close listeners
            ::cppu::OInterfaceContainerHelper* pIC = m_aListenerContainer.getContainer(
                        ::getCppuType((const uno::Reference< util::XCloseListener >*)0) );;
            if( pIC )
            {
                //lang::EventObject aEvent( static_cast< util::XCloseable*>(xCloseable) );
                lang::EventObject aEvent( xCloseable );
                ::cppu::OInterfaceIteratorHelper aIt( *pIC );
                while( aIt.hasMoreElements() )
                {
                    uno::Reference< util::XCloseListener > xListener( aIt.next(), uno::UNO_QUERY );
                    if( xListener.is() )
                        xListener->notifyClosing( aEvent );
                }
            }
        }
    }
    catch( uno::Exception& ex )
    {
        ASSERT_EXCEPTION( ex );
    }

    if(xCloseable.is())
    {
        uno::Reference< lang::XComponent > xComponent =
            uno::Reference< lang::XComponent >( xCloseable, uno::UNO_QUERY );
        if(xComponent.is())
        {
            OSL_ENSURE( m_bClosed, "a not closed component will be disposed " );
            xComponent->dispose();
        }
    }
    //mutex will be reacquired in destructor of aNegativeGuard
}

    sal_Bool CloseableLifeTimeManager
::g_addCloseListener( const uno::Reference< util::XCloseListener > & xListener )
    throw(uno::RuntimeException)
{
    osl::Guard< osl::Mutex > aGuard( m_aAccessMutex );
    //Mutex needs to be acquired exactly ones; will be released inbetween
    if( !impl_canStartApiCall() )
        return sal_False;
    //mutex is acquired

    m_aListenerContainer.addInterface( ::getCppuType((const uno::Reference< util::XCloseListener >*)0),xListener );
    m_bOwnership = sal_False;
    return sal_True;
}

    sal_Bool CloseableLifeTimeManager
::impl_canStartApiCall()
{
    //Mutex needs to be acquired exactly ones before calling this method
    //the mutex will be released inbetween and reacquired

    if( impl_isDisposed() )
        return sal_False; //behave passive if already disposed
    if( m_bClosed )
        return sal_False; //behave passive if closing is already done

    //during try-close most calls need to wait for the decision
    while( m_bInTryClose )
    {
        //if someone tries to close this object at the moment
        //we need to wait for his end because the result of the preceding call
        //is relevant for our behaviour here

        m_aAccessMutex.release();
        m_aEndTryClosingCondition.wait(); //@todo??? this may block??? try closing
        m_aAccessMutex.acquire();
        if( m_bDisposed || m_bInDispose || m_bClosed )
            return sal_False; //return if closed already
    }
    //mutex is acquired
    return sal_True;
}

//--------------------------

    sal_Bool LifeTimeGuard
::startApiCall(sal_Bool bLongLastingCall)
{
    //Mutex needs to be acquired exactly ones; will be released inbetween
    //mutex is requiered due to constructor of LifeTimeGuard

    OSL_ENSURE( !m_bCallRegistered, "this method is only allowed ones" );
    if(m_bCallRegistered)
        return sal_False;

    //Mutex needs to be acquired exactly ones; will be released inbetween
    if( !m_rManager.impl_canStartApiCall() )
        return sal_False;
    //mutex is acquired

    m_bCallRegistered = sal_True;
    m_bLongLastingCallRegistered = bLongLastingCall;
    m_rManager.impl_registerApiCall(bLongLastingCall);
    return sal_True;
}

LifeTimeGuard::~LifeTimeGuard()
{
    try
    {
        //do acquire the mutex if it was cleared before
        osl::MutexGuard g(m_rManager.m_aAccessMutex);
        if(m_bCallRegistered)
        {
            //Mutex needs to be acquired exactly ones
            //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()
            m_rManager.impl_unregisterApiCall(m_bLongLastingCallRegistered);
        }
    }
    catch( uno::Exception& ex )
    {
        //@todo ? allow a uno::RuntimeException from dispose to travel through??
        ex.Context.is(); //to avoid compilation warnings
    }
}

/*
the XCloseable::close method has to be implemented in the following way:
::close
{
    //hold no mutex

    if( !m_aLifeTimeManager.g_close_startTryClose( bDeliverOwnership ) )
        return;
    //no mutex is acquired

    // At the end of this method may we must dispose ourself ...
    // and may nobody from outside hold a reference to us ...
    // then it's a good idea to do that by ourself.
    uno::Reference< uno::XInterface > xSelfHold( static_cast< ::cppu::OWeakObject* >(this) );

    //the listeners have had no veto
    //check wether we self can close
    {
        util::CloseVetoException aVetoException = util::CloseVetoException(
                        ::rtl::OUString( RTL_CONSTASCII_USTRINGPARAM(
                        "the model itself could not be closed" ) )
                        , static_cast< ::cppu::OWeakObject* >(this));

        if( m_aLifeTimeManager.g_close_isNeedToCancelLongLastingCalls( bDeliverOwnership, aVetoException ) )
        {
            ////you can empty this block, if you never start longlasting calls or
            ////if your longlasting calls are per default not cancelable (check how you have constructed your LifeTimeManager)

            sal_Bool bLongLastingCallsAreCanceled = sal_False;
            try
            {
                //try to cancel running longlasting calls
                //// @todo
            }
            catch( uno::Exception& ex )
            {
                //// @todo
                //do not throw anything here!! (without endTryClose)
            }
            //if not successful canceled
            if(!bLongLastingCallsAreCanceled)
            {
                m_aLifeTimeManager.g_close_endTryClose( bDeliverOwnership, sal_True );
                throw aVetoException;
            }
        }

    }
    m_aLifeTimeManager.g_close_endTryClose_doClose();
}
*/

}//end namespace apphelper