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#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 willl 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()

{

    /* On win32-g++, with GCC 3.4.2 std::uncaught_exception() isn't reliable. */

    if (hasException()

#ifndef Q_CC_MINGW

        && std::uncaught_exception() == false

#endif

            ) {

        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