interfacecontainer4.hxx

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
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 *
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 *
 *   Licensed to the Apache Software Foundation (ASF) under one or more
 *   contributor license agreements. See the NOTICE file distributed
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 *   except in compliance with the License. You may obtain a copy of
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 */
#pragma once
 
#include <sal/config.h>
 
#include <com/sun/star/lang/EventObject.hpp>
#include <com/sun/star/lang/DisposedException.hpp>
#include <o3tl/cow_wrapper.hxx>
#include <cassert>
#include <mutex>
#include <vector>
 
namespace com::sun::star::uno
{
class XInterface;
}
 
namespace comphelper
{
template <class ListenerT> class OInterfaceContainerHelper4;
template <class ListenerT> class OInterfaceIteratorHelper4
{
public:
    OInterfaceIteratorHelper4(std::unique_lock<std::mutex>& rGuard,
                              OInterfaceContainerHelper4<ListenerT>& rCont_)
        : rCont(rCont_)
        , maData(rCont.maData)
        // const_cast so we don't trigger make_unique via o3tl::cow_wrapper::operator->
        , nRemain(std::as_const(maData)->size())
    {
        assert(rGuard.owns_lock());
        (void)rGuard;
    }
 
    bool hasMoreElements() const { return nRemain != 0; }
    css::uno::Reference<ListenerT> const& next();
 
    void remove(::std::unique_lock<::std::mutex>& rGuard);
 
private:
    OInterfaceContainerHelper4<ListenerT>& rCont;
    o3tl::cow_wrapper<std::vector<css::uno::Reference<ListenerT>>,
                      o3tl::ThreadSafeRefCountingPolicy>
        maData;
    sal_Int32 nRemain;
 
    OInterfaceIteratorHelper4(const OInterfaceIteratorHelper4&) = delete;
    OInterfaceIteratorHelper4& operator=(const OInterfaceIteratorHelper4&) = delete;
};
 
template <class ListenerT>
const css::uno::Reference<ListenerT>& OInterfaceIteratorHelper4<ListenerT>::next()
{
    nRemain--;
    return (*std::as_const(maData))[nRemain];
}
 
template <class ListenerT>
void OInterfaceIteratorHelper4<ListenerT>::remove(::std::unique_lock<::std::mutex>& rGuard)
{
    rCont.removeInterface(rGuard, (*std::as_const(maData))[nRemain]);
}
 
template <class ListenerT> class OInterfaceContainerHelper4
{
public:
    OInterfaceContainerHelper4();
 
    sal_Int32 getLength(std::unique_lock<std::mutex>& rGuard) const;
 
    std::vector<css::uno::Reference<ListenerT>>
    getElements(std::unique_lock<std::mutex>& rGuard) const;
 
    sal_Int32 addInterface(std::unique_lock<std::mutex>& rGuard,
                           const css::uno::Reference<ListenerT>& rxIFace);
    sal_Int32 removeInterface(std::unique_lock<std::mutex>& rGuard,
                              const css::uno::Reference<ListenerT>& rxIFace);
    void disposeAndClear(::std::unique_lock<::std::mutex>& rGuard,
                         const css::lang::EventObject& rEvt);
    void clear(::std::unique_lock<::std::mutex>& rGuard);
 
    template <typename FuncT>
    inline void forEach(std::unique_lock<std::mutex>& rGuard, FuncT const& func) const;
 
    template <typename EventT>
    inline void notifyEach(std::unique_lock<std::mutex>& rGuard,
                           void (SAL_CALL ListenerT::*NotificationMethod)(const EventT&),
                           const EventT& Event) const;
 
    // this is moveable, but not copyable
    OInterfaceContainerHelper4(OInterfaceContainerHelper4&&) = default;
    OInterfaceContainerHelper4& operator=(OInterfaceContainerHelper4&&) = default;
 
private:
    friend class OInterfaceIteratorHelper4<ListenerT>;
    o3tl::cow_wrapper<std::vector<css::uno::Reference<ListenerT>>,
                      o3tl::ThreadSafeRefCountingPolicy>
        maData;
    OInterfaceContainerHelper4(const OInterfaceContainerHelper4&) = delete;
    OInterfaceContainerHelper4& operator=(const OInterfaceContainerHelper4&) = delete;
 
    static o3tl::cow_wrapper<std::vector<css::uno::Reference<ListenerT>>,
                             o3tl::ThreadSafeRefCountingPolicy>&
    DEFAULT()
    {
        static o3tl::cow_wrapper<std::vector<css::uno::Reference<ListenerT>>,
                                 o3tl::ThreadSafeRefCountingPolicy>
            SINGLETON;
        return SINGLETON;
    }
 
private:
    template <typename EventT> class NotifySingleListener
    {
    private:
        typedef void (SAL_CALL ListenerT::*NotificationMethod)(const EventT&);
        NotificationMethod const m_pMethod;
        const EventT& m_rEvent;
 
    public:
        NotifySingleListener(NotificationMethod method, const EventT& event)
            : m_pMethod(method)
            , m_rEvent(event)
        {
            assert(m_pMethod);
        }
 
        void operator()(const css::uno::Reference<ListenerT>& listener) const
        {
            (listener.get()->*m_pMethod)(m_rEvent);
        }
    };
};
 
template <class T>
inline OInterfaceContainerHelper4<T>::OInterfaceContainerHelper4()
    : maData(OInterfaceContainerHelper4<T>::DEFAULT())
{
}
 
template <class T>
template <typename FuncT>
inline void OInterfaceContainerHelper4<T>::forEach(std::unique_lock<std::mutex>& rGuard,
                                                   FuncT const& func) const
{
    assert(rGuard.owns_lock());
    if (std::as_const(maData)->size() == 0)
    {
        return;
    }
    const_cast<OInterfaceContainerHelper4&>(*this)
        .maData.make_unique(); // so we can iterate over the data without holding the lock
    OInterfaceIteratorHelper4<T> iter(rGuard, const_cast<OInterfaceContainerHelper4&>(*this));
    rGuard.unlock();
    while (iter.hasMoreElements())
    {
        auto xListener = iter.next();
        try
        {
            func(xListener);
        }
        catch (css::lang::DisposedException const& exc)
        {
            if (exc.Context == xListener)
            {
                rGuard.lock();
                iter.remove(rGuard);
                rGuard.unlock();
            }
        }
    }
    rGuard.lock();
}
 
template <class ListenerT>
template <typename EventT>
inline void OInterfaceContainerHelper4<ListenerT>::notifyEach(
    std::unique_lock<std::mutex>& rGuard,
    void (SAL_CALL ListenerT::*NotificationMethod)(const EventT&), const EventT& Event) const
{
    forEach<NotifySingleListener<EventT>>(rGuard,
                                          NotifySingleListener<EventT>(NotificationMethod, Event));
}
 
template <class ListenerT>
sal_Int32
OInterfaceContainerHelper4<ListenerT>::getLength(std::unique_lock<std::mutex>& rGuard) const
{
    assert(rGuard.owns_lock());
    (void)rGuard;
    return maData->size();
}
 
template <class ListenerT>
std::vector<css::uno::Reference<ListenerT>>
OInterfaceContainerHelper4<ListenerT>::getElements(std::unique_lock<std::mutex>& rGuard) const
{
    assert(rGuard.owns_lock());
    (void)rGuard;
    return *maData;
}
 
template <class ListenerT>
sal_Int32
OInterfaceContainerHelper4<ListenerT>::addInterface(std::unique_lock<std::mutex>& rGuard,
                                                    const css::uno::Reference<ListenerT>& rListener)
{
    assert(rGuard.owns_lock());
    (void)rGuard;
    assert(rListener.is());
    maData->push_back(rListener);
    return maData->size();
}
 
template <class ListenerT>
sal_Int32 OInterfaceContainerHelper4<ListenerT>::removeInterface(
    std::unique_lock<std::mutex>& rGuard, const css::uno::Reference<ListenerT>& rListener)
{
    assert(rGuard.owns_lock());
    (void)rGuard;
    assert(rListener.is());
 
    // It is not valid to compare the pointer directly, but it's faster.
    auto it = std::find_if(maData->begin(), maData->end(),
                           [&rListener](const css::uno::Reference<css::uno::XInterface>& rItem) {
                               return rItem.get() == rListener.get();
                           });
 
    // interface not found, use the correct compare method
    if (it == maData->end())
        it = std::find(maData->begin(), maData->end(), rListener);
 
    if (it != maData->end())
        maData->erase(it);
 
    return maData->size();
}
 
template <class ListenerT>
void OInterfaceContainerHelper4<ListenerT>::disposeAndClear(std::unique_lock<std::mutex>& rGuard,
                                                            const css::lang::EventObject& rEvt)
{
    {
        OInterfaceIteratorHelper4<ListenerT> aIt(rGuard, *this);
        maData
            = DEFAULT(); // cheaper than calling maData->clear() because it doesn't allocate a new vector
        rGuard.unlock();
        // unlock followed by iterating is only safe because we are not going to call remove() on the iterator
        while (aIt.hasMoreElements())
        {
            try
            {
                aIt.next()->disposing(rEvt);
            }
            catch (css::uno::RuntimeException&)
            {
                // be robust, if e.g. a remote bridge has disposed already.
                // there is no way to delegate the error to the caller :o(.
            }
        }
    }
    // tdf#152077 need to destruct the OInterfaceIteratorHelper4 before we take the lock again
    // because there is a vague chance that destructing it will trigger a call back into something
    // that wants to take the lock.
    rGuard.lock();
}
 
template <class ListenerT>
void OInterfaceContainerHelper4<ListenerT>::clear(::std::unique_lock<::std::mutex>& rGuard)
{
    assert(rGuard.owns_lock());
    (void)rGuard;
    maData->clear();
}
}
 
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