From 38be0d13830efd2d98281c645c3a60afe05ffece Mon Sep 17 00:00:00 2001 From: Qt by Nokia Date: Wed, 27 Apr 2011 12:05:43 +0200 Subject: Initial import from the monolithic Qt. This is the beginning of revision history for this module. If you want to look at revision history older than this, please refer to the Qt Git wiki for how to use Git history grafting. At the time of writing, this wiki is located here: http://qt.gitorious.org/qt/pages/GitIntroductionWithQt If you have already performed the grafting and you don't see any history beyond this commit, try running "git log" with the "--follow" argument. Branched from the monolithic repo, Qt master branch, at commit 896db169ea224deb96c59ce8af800d019de63f12 --- src/corelib/concurrent/qtconcurrentexception.cpp | 223 +++++++++++++++++++++++ 1 file changed, 223 insertions(+) create mode 100644 src/corelib/concurrent/qtconcurrentexception.cpp (limited to 'src/corelib/concurrent/qtconcurrentexception.cpp') diff --git a/src/corelib/concurrent/qtconcurrentexception.cpp b/src/corelib/concurrent/qtconcurrentexception.cpp new file mode 100644 index 00000000000..b4123f52cac --- /dev/null +++ b/src/corelib/concurrent/qtconcurrentexception.cpp @@ -0,0 +1,223 @@ +/**************************************************************************** +** +** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). +** All rights reserved. +** Contact: Nokia Corporation (qt-info@nokia.com) +** +** This file is part of the QtCore module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the Technology Preview License Agreement accompanying +** this package. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain additional +** rights. These rights are described in the Nokia Qt LGPL Exception +** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. +** +** If you have questions regarding the use of this file, please contact +** Nokia at qt-info@nokia.com. +** +** +** +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include "qtconcurrentexception.h" + +#ifndef QT_NO_QFUTURE +#ifndef QT_NO_EXCEPTIONS + +QT_BEGIN_NAMESPACE + +/*! + \class QtConcurrent::Exception + \brief The Exception class provides a base class for exceptions that can transferred across threads. + \since 4.4 + + Qt Concurrent supports throwing and catching exceptions across thread + boundaries, provided that the exception inherit from QtConcurrent::Exception + and implement two helper functions: + + \snippet doc/src/snippets/code/src_corelib_concurrent_qtconcurrentexception.cpp 0 + + QtConcurrent::Exception subclasses must be thrown by value and + caught by reference: + + \snippet doc/src/snippets/code/src_corelib_concurrent_qtconcurrentexception.cpp 1 + + If you throw an exception that is not a subclass of QtConcurrent::Exception, + the Qt Concurrent functions will throw a QtConcurrent::UnhandledException + in the receiver thread. + + When using QFuture, transferred exceptions will be thrown when calling the following functions: + \list + \o QFuture::waitForFinished() + \o QFuture::result() + \o QFuture::resultAt() + \o QFuture::results() + \endlist +*/ + +/*! + \fn QtConcurrent::Exception::raise() const + In your QtConcurrent::Exception subclass, reimplement raise() like this: + + \snippet doc/src/snippets/code/src_corelib_concurrent_qtconcurrentexception.cpp 2 +*/ + +/*! + \fn QtConcurrent::Exception::clone() const + In your QtConcurrent::Exception subclass, reimplement clone() like this: + + \snippet doc/src/snippets/code/src_corelib_concurrent_qtconcurrentexception.cpp 3 +*/ + +/*! + \class QtConcurrent::UnhandledException + + \brief The UnhandledException class represents an unhandled exception in a worker thread. + \since 4.4 + + If a worker thread throws an exception that is not a subclass of QtConcurrent::Exception, + the Qt Concurrent functions will throw a QtConcurrent::UnhandledException + on the receiver thread side. + + Inheriting from this class is not supported. +*/ + +/*! + \fn QtConcurrent::UnhandledException::raise() const + \internal +*/ + +/*! + \fn QtConcurrent::UnhandledException::clone() const + \internal +*/ + +namespace QtConcurrent +{ + +void Exception::raise() const +{ + Exception e = *this; + throw e; +} + +Exception *Exception::clone() const +{ + return new Exception(*this); +} + +void UnhandledException::raise() const +{ + UnhandledException e = *this; + throw e; +} + +Exception *UnhandledException::clone() const +{ + return new UnhandledException(*this); +} + +#ifndef qdoc + +namespace internal { + +class Base +{ +public: + Base(Exception *exception) + : exception(exception), refCount(1), hasThrown(false) { } + ~Base() { delete exception; } + + Exception *exception; + QAtomicInt refCount; + bool hasThrown; +}; + +ExceptionHolder::ExceptionHolder(Exception *exception) +: base(new Base(exception)) {} + +ExceptionHolder::ExceptionHolder(const ExceptionHolder &other) +: base(other.base) +{ + base->refCount.ref(); +} + +void ExceptionHolder::operator=(const ExceptionHolder &other) +{ + if (base == other.base) + return; + + if (base->refCount.deref() == false) + delete base; + + base = other.base; + base->refCount.ref(); +} + +ExceptionHolder::~ExceptionHolder() +{ + if (base->refCount.deref() == 0) + delete base; +} + +Exception *ExceptionHolder::exception() const +{ + return base->exception; +} + +void ExceptionStore::setException(const Exception &e) +{ + if (hasException() == false) + exceptionHolder = ExceptionHolder(e.clone()); +} + +bool ExceptionStore::hasException() const +{ + return (exceptionHolder.exception() != 0); +} + +ExceptionHolder ExceptionStore::exception() +{ + return exceptionHolder; +} + +void ExceptionStore::throwPossibleException() +{ + if (hasException() ) { + exceptionHolder.base->hasThrown = true; + exceptionHolder.exception()->raise(); + } +} + +bool ExceptionStore::hasThrown() const { return exceptionHolder.base->hasThrown; } + +} // namespace internal + +#endif //qdoc + +} // namespace QtConcurrent + +QT_END_NAMESPACE + +#endif // QT_NO_EXCEPTIONS +#endif // QT_NO_CONCURRENT -- cgit v1.2.3