/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */

/*

 * This file is part of the LibreOffice project.

 *

 * 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/.

 *

 * This file incorporates work covered by the following license notice:

 *

 *   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 .

 */

#include <LifeTime.hxx>

#include <osl/diagnose.h>

#include <com/sun/star/document/XStorageChangeListener.hpp>

#include <com/sun/star/lang/XComponent.hpp>

#include <com/sun/star/util/CloseVetoException.hpp>

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

#include <com/sun/star/util/XCloseable.hpp>

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

#include <com/sun/star/view/XSelectionChangeListener.hpp>

#include <comphelper/diagnose_ex.hxx>

#include <sal/log.hxx>

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

namespace apphelper

{

LifeTimeManager::LifeTimeManager( lang::XComponent* pComponent )

    : m_pComponent(pComponent)

{

    m_bDisposed = false;

    m_bInDispose = 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_FAIL( "This component is already disposed " );

        }

        return true;

    }

    return false;

}

bool LifeTimeManager::impl_canStartApiCall()

{

    if( impl_isDisposed() )

        return false; //behave passive if already disposed

    //mutex is acquired

    return true;

}

void LifeTimeManager::impl_registerApiCall(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(std::unique_lock<std::mutex>& rGuard, bool bLongLastingCall)

{

    //Mutex needs to be acquired exactly once

    //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(rGuard);

    }

}

bool LifeTimeManager::dispose()

{

    //hold no mutex

    {

        std::unique_lock aGuard( m_aAccessMutex );

        if( m_bDisposed || m_bInDispose )

        {

            SAL_WARN("chart2",  "This component is already disposed " );

            return 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

        uno::Reference< lang::XComponent > xComponent(m_pComponent);

        if(xComponent.is())

        {

            // notify XCLoseListeners

            lang::EventObject aEvent( xComponent );

            m_aCloseListeners.disposeAndClear( aGuard, aEvent );

            m_aModifyListeners.disposeAndClear( aGuard, aEvent );

            m_aStorageChangeListeners.disposeAndClear( aGuard, aEvent );

            m_aEventListeners.disposeAndClear( aGuard, aEvent );

            m_aSelectionChangeListeners.disposeAndClear( aGuard, aEvent );

        }

        OSL_ENSURE( !m_bDisposed, "dispose was called already" );

        m_bDisposed = true;

    }

    //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 true;

    //--release all resources and references after calling this method successful

}

CloseableLifeTimeManager::CloseableLifeTimeManager( css::util::XCloseable* pCloseable

        , css::lang::XComponent* pComponent )

        : LifeTimeManager( pComponent )

        , m_pCloseable(pCloseable)

{

    m_bClosed = false;

    m_bInTryClose = false;

    m_bOwnership = false;

    m_aEndTryClosingCondition.set();

}

CloseableLifeTimeManager::~CloseableLifeTimeManager()

{

}

bool CloseableLifeTimeManager::impl_isDisposedOrClosed( bool bAssert )

{

    if( impl_isDisposed( bAssert ) )

        return true;

    if( m_bClosed )

    {

        if( bAssert )

        {

            OSL_FAIL( "This object is already closed" );

        }

        return true;

    }

    return false;

}

bool CloseableLifeTimeManager::g_close_startTryClose(bool bDeliverOwnership)

{

    //no mutex is allowed to be acquired

    {

        std::unique_lock aGuard( m_aAccessMutex );

        if( impl_isDisposedOrClosed(false) )

            return false;

        //Mutex needs to be acquired exactly once; will be released inbetween

        if( !impl_canStartApiCall() )

            return false;

        //mutex is acquired

        //not closed already -> we try to close again

        m_bInTryClose = true;

        m_aEndTryClosingCondition.reset();

        impl_registerApiCall(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(m_pCloseable);

        if(xCloseable.is())

        {

            std::unique_lock aGuard( m_aAccessMutex );

            //--call queryClosing on all registered close listeners

            if( m_aCloseListeners.getLength(aGuard) )

            {

                lang::EventObject aEvent( xCloseable );

                m_aCloseListeners.forEach(aGuard,

                    [&aEvent, bDeliverOwnership](const uno::Reference<util::XCloseListener>& l)

                    {

                        l->queryClosing(aEvent, bDeliverOwnership);

                    });

            }

        }

    }

    catch( const uno::Exception& )

    {

        //no mutex is acquired

        g_close_endTryClose();

        throw;

    }

    return true;

}

void CloseableLifeTimeManager::g_close_endTryClose()

{

    //this method is called, if the try to close was not successful

    std::unique_lock aGuard( m_aAccessMutex );

    m_bOwnership = false;

    m_bInTryClose = false;

    m_aEndTryClosingCondition.set();

    //Mutex needs to be acquired exactly once

    //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()

    impl_unregisterApiCall(aGuard, false);

}

void CloseableLifeTimeManager::g_close_isNeedToCancelLongLastingCalls( bool bDeliverOwnership, util::CloseVetoException const & ex )

{

    //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

    std::unique_lock 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;

    m_bOwnership = bDeliverOwnership;

    m_bInTryClose = false;

    m_aEndTryClosingCondition.set();

    //Mutex needs to be acquired exactly once

    //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()

    impl_unregisterApiCall(aGuard, false);

    throw ex;

}

void CloseableLifeTimeManager::g_close_endTryClose_doClose()

{

    //this method is called, if the try to close was successful

    std::unique_lock aGuard( m_aAccessMutex );

    m_bInTryClose       = false;

    m_aEndTryClosingCondition.set();

    //Mutex needs to be acquired exactly once

    //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()

    impl_unregisterApiCall(aGuard, false);

    impl_doClose(aGuard);

}

void CloseableLifeTimeManager::impl_apiCallCountReachedNull(std::unique_lock<std::mutex>& rGuard)

{

    //Mutex needs to be acquired exactly once

    //mutex will be released inbetween in impl_doClose()

    if( m_pCloseable && m_bOwnership )

        impl_doClose(rGuard);

}

void CloseableLifeTimeManager::impl_doClose(std::unique_lock<std::mutex>& rGuard)

{

    //Mutex needs to be acquired exactly once 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 = true;

    uno::Reference< util::XCloseable > xCloseable;

    xCloseable.set(m_pCloseable);

    try

    {

        if(xCloseable.is())

        {

            //--call notifyClosing on all registered close listeners

            if( m_aCloseListeners.getLength(rGuard) )

            {

                lang::EventObject aEvent( xCloseable );

                m_aCloseListeners.notifyEach(rGuard, &util::XCloseListener::notifyClosing, aEvent);

            }

        }

    }

    catch( const uno::Exception& )

    {

        DBG_UNHANDLED_EXCEPTION("chart2");

    }

    rGuard.unlock();

    if(xCloseable.is())

    {

        uno::Reference< lang::XComponent > xComponent( xCloseable, uno::UNO_QUERY );

        if(xComponent.is())

        {

            OSL_ENSURE( m_bClosed, "a not closed component will be disposed " );

            xComponent->dispose();

        }

    }

    rGuard.lock();

}

void CloseableLifeTimeManager::g_addCloseListener( const uno::Reference< util::XCloseListener > & xListener )

{

    std::unique_lock aGuard( m_aAccessMutex );

    //Mutex needs to be acquired exactly once; will be released inbetween

    if( !impl_canStartApiCall() )

        return;

    //mutex is acquired

    m_aCloseListeners.addInterface( aGuard, xListener );

    m_bOwnership = false;

}

bool CloseableLifeTimeManager::impl_canStartApiCall()

{

    //Mutex needs to be acquired exactly once before calling this method

    //the mutex will be released inbetween and reacquired

    if( impl_isDisposed() )

        return false; //behave passive if already disposed

    if( m_bClosed )

        return 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.unlock();

        m_aEndTryClosingCondition.wait(); //@todo??? this may block??? try closing

        m_aAccessMutex.lock();

        if( m_bDisposed || m_bInDispose || m_bClosed )

            return false; //return if closed already

    }

    //mutex is acquired

    return true;

}

bool LifeTimeGuard::startApiCall(bool bLongLastingCall)

{

    //Mutex needs to be acquired exactly once; will be released inbetween

    //mutex is required due to constructor of LifeTimeGuard

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

    if(m_bCallRegistered)

        return false;

    //Mutex needs to be acquired exactly once; will be released inbetween

    if( !m_rManager.impl_canStartApiCall() )

        return false;

    //mutex is acquired

    m_bCallRegistered = true;

    m_bLongLastingCallRegistered = bLongLastingCall;

    m_rManager.impl_registerApiCall(bLongLastingCall);

    return true;

}

LifeTimeGuard::~LifeTimeGuard()

{

    try

    {

        //do acquire the mutex if it was cleared before

        if (!m_guard.owns_lock())

            m_guard.lock();

        if(m_bCallRegistered)

        {

            //Mutex needs to be acquired exactly once

            //mutex may be released inbetween in special case of impl_apiCallCountReachedNull()

            m_rManager.impl_unregisterApiCall(m_guard, m_bLongLastingCallRegistered);

        }

    }

    catch( uno::Exception& ex )

    {

        //@todo ? allow a uno::RuntimeException from dispose to travel through??

        ex.Context.is(); //to avoid compilation warnings

    }

}

}//end namespace apphelper

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */