/* -*- 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 . */ /* MtaOleClipb.cxx - documentation This class setup a single threaded apartment (sta) thread to deal with the ole clipboard, which runs only in an sta thread. The consequence is that callback from the ole clipboard are in the context of this sta thread. In the soffice applications this may lead to problems because they all use the one and only mutex called SolarMutex. In order to transfer clipboard requests to our sta thread we use a hidden window and forward these requests via window messages. */ #include #include #include "MtaOleClipb.hxx" #include #include #include #include #include #include #include #include namespace /* private */ { const wchar_t g_szWndClsName[] = L"MtaOleReqWnd###"; // messages constants const sal_uInt32 MSG_SETCLIPBOARD = WM_USER + 0x0001; const sal_uInt32 MSG_GETCLIPBOARD = WM_USER + 0x0002; const sal_uInt32 MSG_REGCLIPVIEWER = WM_USER + 0x0003; const sal_uInt32 MSG_FLUSHCLIPBOARD = WM_USER + 0x0004; const sal_uInt32 MSG_SHUTDOWN = WM_USER + 0x0005; const sal_uInt32 MAX_WAITTIME = 10000; // msec const sal_uInt32 MAX_WAIT_SHUTDOWN = 10000; // msec const bool MANUAL_RESET = true; const bool INIT_NONSIGNALED = false; /* Cannot use osl conditions because they are blocking without waking up on messages sent by another thread this leads to deadlocks because we are blocking the communication between inter-thread marshalled COM pointers. COM Proxy-Stub communication uses SendMessages for synchronization purposes. */ class Win32Condition { public: Win32Condition() = default; ~Win32Condition() { CloseHandle(m_hEvent); } // wait infinite for own event (or abort event) be signaled // leave messages sent through bool wait(HANDLE hEvtAbort) { const HANDLE hWaitArray[2] = { m_hEvent, hEvtAbort }; while (true) { DWORD dwResult = MsgWaitForMultipleObjects(2, hWaitArray, FALSE, INFINITE, QS_SENDMESSAGE); switch (dwResult) { case WAIT_OBJECT_0: // wait successful return true; case WAIT_OBJECT_0 + 1: // wait aborted return false; case WAIT_OBJECT_0 + 2: { /* PeekMessage processes all messages in the SendMessage queue that's what we want, messages from the PostMessage queue stay untouched */ MSG msg; PeekMessageW(&msg, nullptr, 0, 0, PM_NOREMOVE); break; } default: // WAIT_FAILED? return false; } } } // set the event void set() { SetEvent(m_hEvent); } private: HANDLE m_hEvent = CreateEventW(nullptr, MANUAL_RESET, INIT_NONSIGNALED, nullptr); // prevent copy/assignment Win32Condition(const Win32Condition&) = delete; Win32Condition& operator=(const Win32Condition&) = delete; }; // we use one condition for every request struct MsgCtx { Win32Condition aCondition; HRESULT hr; }; } /* namespace private */ // static member initialization CMtaOleClipboard* CMtaOleClipboard::s_theMtaOleClipboardInst = nullptr; // marshal an IDataObject //inline static HRESULT MarshalIDataObjectInStream( IDataObject* pIDataObject, LPSTREAM* ppStream ) { OSL_ASSERT( nullptr != pIDataObject ); assert(nullptr != ppStream); *ppStream = nullptr; return CoMarshalInterThreadInterfaceInStream( __uuidof(IDataObject), //The IID of interface to be marshalled pIDataObject, //The interface pointer ppStream //IStream pointer ); } // unmarshal an IDataObject //inline static HRESULT UnmarshalIDataObjectAndReleaseStream( LPSTREAM lpStream, IDataObject** ppIDataObject ) { OSL_ASSERT( nullptr != lpStream ); assert(nullptr != ppIDataObject); *ppIDataObject = nullptr; return CoGetInterfaceAndReleaseStream( lpStream, __uuidof(IDataObject), reinterpret_cast(ppIDataObject)); } // helper class to ensure that the calling thread has com initialized namespace { class CAutoComInit { public: /* to be safe we call CoInitializeEx although it is not necessary if the calling thread was created using osl_CreateThread because this function calls CoInitializeEx for every thread it creates */ CAutoComInit( ) : m_hResult( CoInitializeEx( nullptr, COINIT_APARTMENTTHREADED ) ) { if ( S_OK == m_hResult ) OSL_FAIL( "com was not yet initialized, the thread was not created using osl_createThread" ); else if ( FAILED( m_hResult ) && !( RPC_E_CHANGED_MODE == m_hResult ) ) OSL_FAIL( "com could not be initialized, maybe the thread was not created using osl_createThread" ); } ~CAutoComInit( ) { /* we only call CoUninitialize when CoInitializeEx returned S_FALSE, what means that com was already initialize for that thread so we keep the balance if CoInitializeEx returned S_OK what means com was not yet initialized we better let com initialized or we may run into the realm of undefined behaviour */ if ( m_hResult == S_FALSE ) CoUninitialize( ); } private: HRESULT m_hResult; }; } // ctor CMtaOleClipboard::CMtaOleClipboard( ) : m_hOleThread( nullptr ), m_uOleThreadId( 0 ), // signals that the thread was successfully setup m_hEvtThrdReady(CreateEventW( nullptr, MANUAL_RESET, INIT_NONSIGNALED, nullptr )), m_hwndMtaOleReqWnd( nullptr ), // signals that the window is destroyed - to stop waiting any winproc result m_hEvtWndDisposed(CreateEventW(nullptr, MANUAL_RESET, INIT_NONSIGNALED, nullptr)), m_MtaOleReqWndClassAtom( 0 ), m_pfncClipViewerCallback( nullptr ), m_bRunClipboardNotifierThread( true ), m_hClipboardChangedEvent( m_hClipboardChangedNotifierEvents[0] ), m_hTerminateClipboardChangedNotifierEvent( m_hClipboardChangedNotifierEvents[1] ), m_ClipboardChangedEventCount( 0 ) { OSL_ASSERT( nullptr != m_hEvtThrdReady ); SAL_WARN_IF(!m_hEvtWndDisposed, "vcl.win.dtrans", "CreateEventW failed: m_hEvtWndDisposed is nullptr"); s_theMtaOleClipboardInst = this; m_hOleThread = reinterpret_cast(_beginthreadex( nullptr, 0, CMtaOleClipboard::oleThreadProc, this, 0, &m_uOleThreadId )); OSL_ASSERT( nullptr != m_hOleThread ); // setup the clipboard changed notifier thread m_hClipboardChangedNotifierEvents[0] = CreateEventW( nullptr, MANUAL_RESET, INIT_NONSIGNALED, nullptr ); OSL_ASSERT( nullptr != m_hClipboardChangedNotifierEvents[0] ); m_hClipboardChangedNotifierEvents[1] = CreateEventW( nullptr, MANUAL_RESET, INIT_NONSIGNALED, nullptr ); OSL_ASSERT( nullptr != m_hClipboardChangedNotifierEvents[1] ); m_hClipboardChangedNotifierThread = reinterpret_cast(_beginthreadex( nullptr, 0, CMtaOleClipboard::clipboardChangedNotifierThreadProc, this, 0, nullptr )); OSL_ASSERT( nullptr != m_hClipboardChangedNotifierThread ); } // dtor CMtaOleClipboard::~CMtaOleClipboard( ) { // block calling threads out if ( nullptr != m_hEvtThrdReady ) ResetEvent( m_hEvtThrdReady ); // terminate the clipboard changed notifier thread m_bRunClipboardNotifierThread = false; SetEvent( m_hTerminateClipboardChangedNotifierEvent ); // unblock whoever could still wait for event processing if (m_hEvtWndDisposed) SetEvent(m_hEvtWndDisposed); sal_uInt32 dwResult = WaitForSingleObject( m_hClipboardChangedNotifierThread, MAX_WAIT_SHUTDOWN ); OSL_ENSURE( dwResult == WAIT_OBJECT_0, "clipboard notifier thread could not terminate" ); if ( nullptr != m_hClipboardChangedNotifierThread ) CloseHandle( m_hClipboardChangedNotifierThread ); if ( nullptr != m_hClipboardChangedNotifierEvents[0] ) CloseHandle( m_hClipboardChangedNotifierEvents[0] ); if ( nullptr != m_hClipboardChangedNotifierEvents[1] ) CloseHandle( m_hClipboardChangedNotifierEvents[1] ); // end the thread // because DestroyWindow can only be called // from within the thread that created the window sendMessage( MSG_SHUTDOWN ); // wait for thread shutdown dwResult = WaitForSingleObject( m_hOleThread, MAX_WAIT_SHUTDOWN ); OSL_ENSURE( dwResult == WAIT_OBJECT_0, "OleThread could not terminate" ); if ( nullptr != m_hOleThread ) CloseHandle( m_hOleThread ); if ( nullptr != m_hEvtThrdReady ) CloseHandle( m_hEvtThrdReady ); if (m_hEvtWndDisposed) CloseHandle(m_hEvtWndDisposed); if ( m_MtaOleReqWndClassAtom ) UnregisterClassW( g_szWndClsName, nullptr ); OSL_ENSURE( ( nullptr == m_pfncClipViewerCallback ), "Clipboard viewer not properly unregistered" ); } HRESULT CMtaOleClipboard::flushClipboard( ) { if ( !WaitForThreadReady( ) ) { OSL_FAIL( "clipboard sta thread not ready" ); return E_FAIL; } OSL_ENSURE( GetCurrentThreadId( ) != m_uOleThreadId, "flushClipboard from within clipboard sta thread called" ); MsgCtx aMsgCtx; const bool bWaitSuccess = postMessage(MSG_FLUSHCLIPBOARD, 0, reinterpret_cast(&aMsgCtx)) && aMsgCtx.aCondition.wait(m_hEvtWndDisposed); return bWaitSuccess ? aMsgCtx.hr : E_ABORT; } HRESULT CMtaOleClipboard::getClipboard( IDataObject** ppIDataObject ) { assert(ppIDataObject && "invalid parameter"); OSL_PRECOND( GetCurrentThreadId( ) != m_uOleThreadId, "getClipboard from within clipboard sta thread called" ); if ( !WaitForThreadReady( ) ) { OSL_FAIL( "clipboard sta thread not ready" ); return E_FAIL; } CAutoComInit comAutoInit; LPSTREAM lpStream; *ppIDataObject = nullptr; MsgCtx aMsgCtx; const bool bWaitSuccess = postMessage(MSG_GETCLIPBOARD, reinterpret_cast(&lpStream), reinterpret_cast(&aMsgCtx)) && aMsgCtx.aCondition.wait(m_hEvtWndDisposed); HRESULT hr = bWaitSuccess ? aMsgCtx.hr : E_ABORT; if ( SUCCEEDED( hr ) ) { hr = UnmarshalIDataObjectAndReleaseStream( lpStream, ppIDataObject ); OSL_ENSURE( SUCCEEDED( hr ), "unmarshalling clipboard data object failed" ); } return hr; } // this is an asynchronous method that's why we don't wait until the // request is completed HRESULT CMtaOleClipboard::setClipboard( IDataObject* pIDataObject ) { if ( !WaitForThreadReady( ) ) { OSL_FAIL( "clipboard sta thread not ready" ); return E_FAIL; } CAutoComInit comAutoInit; OSL_ENSURE( GetCurrentThreadId( ) != m_uOleThreadId, "setClipboard from within the clipboard sta thread called" ); // because we marshall this request // into the sta thread we better // acquire the interface here so // that the object will not be // destroyed before the ole clipboard // can acquire it // remember: pIDataObject may be NULL // which is a request to clear the // current clipboard content if ( pIDataObject ) pIDataObject->AddRef( ); postMessage( MSG_SETCLIPBOARD, reinterpret_cast< WPARAM >( pIDataObject ) ); // because this is an asynchronous function // the return value is useless return S_OK; } // register a clipboard viewer bool CMtaOleClipboard::registerClipViewer( LPFNC_CLIPVIEWER_CALLBACK_t pfncClipViewerCallback ) { if ( !WaitForThreadReady( ) ) { OSL_FAIL( "clipboard sta thread not ready" ); return false; } OSL_ENSURE( GetCurrentThreadId( ) != m_uOleThreadId, "registerClipViewer from within the OleThread called" ); MsgCtx aMsgCtx; if (postMessage(MSG_REGCLIPVIEWER, reinterpret_cast(pfncClipViewerCallback), reinterpret_cast(&aMsgCtx))) aMsgCtx.aCondition.wait(m_hEvtWndDisposed); return false; } // register a clipboard viewer bool CMtaOleClipboard::onRegisterClipViewer( LPFNC_CLIPVIEWER_CALLBACK_t pfncClipViewerCallback ) { bool bRet = false; // we need exclusive access because the clipboard changed notifier // thread also accesses this variable std::unique_lock aGuard( m_pfncClipViewerCallbackMutex ); // register if not yet done if ( ( nullptr != pfncClipViewerCallback ) && ( nullptr == m_pfncClipViewerCallback ) ) { // SetClipboardViewer sends a WM_DRAWCLIPBOARD message we ignore // this message if we register ourself as clip viewer m_bInRegisterClipViewer = true; bRet = AddClipboardFormatListener(m_hwndMtaOleReqWnd); m_bInRegisterClipViewer = false; // save the new callback function m_pfncClipViewerCallback = pfncClipViewerCallback; } else if ( ( nullptr == pfncClipViewerCallback ) && ( nullptr != m_pfncClipViewerCallback ) ) { m_pfncClipViewerCallback = nullptr; // unregister if input parameter is NULL and we previously registered // as clipboard viewer bRet = RemoveClipboardFormatListener(m_hwndMtaOleReqWnd); } return bRet; } HRESULT CMtaOleClipboard::onSetClipboard( IDataObject* pIDataObject ) { return sal::systools::RetryIfFailed(10, 100, [pIDataObject] { return OleSetClipboard(pIDataObject); }); } HRESULT CMtaOleClipboard::onGetClipboard( LPSTREAM* ppStream ) { OSL_ASSERT(nullptr != ppStream); IDataObjectPtr pIDataObject; // forward the request to the OleClipboard HRESULT hr = sal::systools::RetryIfFailed(10, 100, [p = &pIDataObject] { return OleGetClipboard(p); }); if ( SUCCEEDED( hr ) ) { hr = MarshalIDataObjectInStream(pIDataObject.get(), ppStream); OSL_ENSURE(SUCCEEDED(hr), "marshalling clipboard data object failed"); } return hr; } // flush the ole-clipboard HRESULT CMtaOleClipboard::onFlushClipboard( ) { return sal::systools::RetryIfFailed(10, 100, [] { return OleFlushClipboard(); }); } // handle clipboard update event LRESULT CMtaOleClipboard::onClipboardUpdate() { // we don't send a notification if we are // registering ourself as clipboard if ( !m_bInRegisterClipViewer ) { std::unique_lock aGuard( m_ClipboardChangedEventCountMutex ); m_ClipboardChangedEventCount++; SetEvent( m_hClipboardChangedEvent ); } return 0; } // SendMessage so we don't need to supply the HWND if we send // something to our wrapped window LRESULT CMtaOleClipboard::sendMessage( UINT msg, WPARAM wParam, LPARAM lParam ) { return ::SendMessageW( m_hwndMtaOleReqWnd, msg, wParam, lParam ); } // PostMessage so we don't need to supply the HWND if we send // something to our wrapped window bool CMtaOleClipboard::postMessage( UINT msg, WPARAM wParam, LPARAM lParam ) { bool const ret = PostMessageW(m_hwndMtaOleReqWnd, msg, wParam, lParam); SAL_WARN_IF(!ret, "vcl.win.dtrans", "ERROR: PostMessage() failed!"); return ret; } // the window proc LRESULT CALLBACK CMtaOleClipboard::mtaOleReqWndProc( HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam ) { LRESULT lResult = 0; // get a connection to the class-instance via the static member CMtaOleClipboard* pImpl = CMtaOleClipboard::s_theMtaOleClipboardInst; assert(pImpl); switch( uMsg ) { case MSG_SETCLIPBOARD: { IDataObject* pIDataObject = reinterpret_cast< IDataObject* >( wParam ); CMtaOleClipboard::onSetClipboard( pIDataObject ); // in setClipboard we did acquire the // interface pointer in order to prevent // destruction of the object before the // ole clipboard can acquire the interface // now we release the interface so that // our lostOwnership mechanism works // remember: pIDataObject may be NULL if ( pIDataObject ) pIDataObject->Release( ); } break; case MSG_GETCLIPBOARD: { MsgCtx* aMsgCtx = reinterpret_cast< MsgCtx* >( lParam ); assert(aMsgCtx); aMsgCtx->hr = CMtaOleClipboard::onGetClipboard( reinterpret_cast< LPSTREAM* >(wParam) ); aMsgCtx->aCondition.set( ); } break; case MSG_FLUSHCLIPBOARD: { MsgCtx* aMsgCtx = reinterpret_cast< MsgCtx* >( lParam ); assert(aMsgCtx); aMsgCtx->hr = CMtaOleClipboard::onFlushClipboard( ); aMsgCtx->aCondition.set( ); } break; case MSG_REGCLIPVIEWER: { MsgCtx* pMsgCtx = reinterpret_cast(lParam); assert(pMsgCtx && "pMsgCtx is nullptr"); pImpl->onRegisterClipViewer( reinterpret_cast(wParam)); pMsgCtx->aCondition.set(); } break; case WM_CLIPBOARDUPDATE: lResult = pImpl->onClipboardUpdate(); break; case MSG_SHUTDOWN: DestroyWindow( pImpl->m_hwndMtaOleReqWnd ); break; // force the sta thread to end case WM_DESTROY: SetEvent(pImpl->m_hEvtWndDisposed); // stop waiting for conditions set by this wndproc PostQuitMessage( 0 ); break; default: lResult = DefWindowProcW( hWnd, uMsg, wParam, lParam ); break; } return lResult; } void CMtaOleClipboard::createMtaOleReqWnd( ) { WNDCLASSEXW wcex; SalData* pSalData = GetSalData(); OSL_ASSERT(nullptr != pSalData->mhInst); ZeroMemory( &wcex, sizeof(wcex) ); wcex.cbSize = sizeof(wcex); wcex.style = 0; wcex.lpfnWndProc = CMtaOleClipboard::mtaOleReqWndProc; wcex.cbClsExtra = 0; wcex.cbWndExtra = 0; wcex.hInstance = pSalData->mhInst; wcex.hIcon = nullptr; wcex.hCursor = nullptr; wcex.hbrBackground = nullptr; wcex.lpszMenuName = nullptr; wcex.lpszClassName = g_szWndClsName; wcex.hIconSm = nullptr; m_MtaOleReqWndClassAtom = RegisterClassExW( &wcex ); if ( 0 != m_MtaOleReqWndClassAtom ) m_hwndMtaOleReqWnd = CreateWindowW( g_szWndClsName, nullptr, 0, 0, 0, 0, 0, nullptr, nullptr, pSalData->mhInst, nullptr ); } unsigned int CMtaOleClipboard::run( ) { HRESULT hr = OleInitialize( nullptr ); OSL_ASSERT( SUCCEEDED( hr ) ); createMtaOleReqWnd( ); unsigned int nRet = ~0U; // = error if ( IsWindow( m_hwndMtaOleReqWnd ) ) { if ( nullptr != m_hEvtThrdReady ) SetEvent( m_hEvtThrdReady ); nRet = 0; // pumping messages for (;;) { MSG msg; int const bRet = GetMessageW(&msg, nullptr, 0, 0); if (bRet == 0) { break; } if (-1 == bRet) { SAL_WARN("vcl.win.dtrans", "GetMessageW failed: " << WindowsErrorString(GetLastError())); nRet = ~0U; break; } DispatchMessageW(&msg); } } OleUninitialize( ); return nRet; } unsigned __stdcall CMtaOleClipboard::oleThreadProc( void* pParam ) { osl_setThreadName("CMtaOleClipboard::run()"); CMtaOleClipboard* pInst = static_cast( pParam ); OSL_ASSERT( nullptr != pInst ); return pInst->run( ); } unsigned __stdcall CMtaOleClipboard::clipboardChangedNotifierThreadProc(void* pParam) { osl_setThreadName("CMtaOleClipboard::clipboardChangedNotifierThreadProc()"); CMtaOleClipboard* pInst = static_cast< CMtaOleClipboard* >( pParam ); assert(pInst); sal::systools::CoInitializeGuard aGuard(COINIT_APARTMENTTHREADED, false, sal::systools::CoInitializeGuard::WhenFailed::NoThrow); // assuming we don't need a lock for // a boolean variable like m_bRun... while ( pInst->m_bRunClipboardNotifierThread ) { // process window messages because of CoInitializeEx MSG Msg; while (PeekMessageW(&Msg, nullptr, 0, 0, PM_REMOVE)) DispatchMessageW(&Msg); // wait for clipboard changed or terminate event MsgWaitForMultipleObjects(2, pInst->m_hClipboardChangedNotifierEvents, false, INFINITE, QS_ALLINPUT | QS_ALLPOSTMESSAGE); bool hadEvents; { std::unique_lock aGuard2(pInst->m_ClipboardChangedEventCountMutex); hadEvents = pInst->m_ClipboardChangedEventCount > 0; if (hadEvents) { pInst->m_ClipboardChangedEventCount--; if (0 == pInst->m_ClipboardChangedEventCount) ResetEvent(pInst->m_hClipboardChangedEvent); } } if (hadEvents) { LPFNC_CLIPVIEWER_CALLBACK_t pClipViewerCallback; { // nobody should touch m_pfncClipViewerCallback while we do // but don't hold the mutex while calling the callback itself: it could deadlock std::unique_lock aClipViewerGuard(pInst->m_pfncClipViewerCallbackMutex); pClipViewerCallback = pInst->m_pfncClipViewerCallback; } // notify all clipboard listener if (pClipViewerCallback) pClipViewerCallback(); } } return 0; } bool CMtaOleClipboard::WaitForThreadReady( ) const { bool bRet = false; if ( nullptr != m_hEvtThrdReady ) { DWORD dwResult = WaitForSingleObject( m_hEvtThrdReady, MAX_WAITTIME ); bRet = ( dwResult == WAIT_OBJECT_0 ); } return bRet; } /* vim:set shiftwidth=4 softtabstop=4 expandtab: */