Move QtConcurrent::Exception as QException back to QtCore

Leave the old name as a deprecated typedef; adapt users.

This is a prerequisite for moving QFuture back to QtCore.

Change-Id: I81dcee2c7e6eb234c16f3f42e2415ca0da3dc4f8
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

3 files changed, 331 insertions, 0 deletions

diff --git a/src/corelib/thread/qexception.cpp b/src/corelib/thread/qexception.cpp
new file mode 100644
index 0000000000..090cbf4e85
--- /dev/null
+++ b/src/corelib/thread/qexception.cpp
@@ -0,0 +1,206 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qexception.h"
+#include "QtCore/qshareddata.h"
+
+#ifndef QT_NO_QFUTURE
+#ifndef QT_NO_EXCEPTIONS
+
+QT_BEGIN_NAMESPACE
+
+/*! 
+    \class QException
+    \brief The QException class provides a base class for exceptions that can transferred across threads.
+    \since 5.0
+
+    Qt Concurrent supports throwing and catching exceptions across thread
+    boundaries, provided that the exception inherit from QException
+    and implement two helper functions:
+
+    \snippet code/src_corelib_thread_qexception.cpp 0
+
+    QException subclasses must be thrown by value and
+    caught by reference:
+
+    \snippet code/src_corelib_thread_qexception.cpp 1
+
+    If you throw an exception that is not a subclass of QException,
+    the Qt functions will throw a QUnhandledException
+    in the receiver thread.
+
+    When using QFuture, transferred exceptions will be thrown when calling the following functions:
+    \list
+    \li QFuture::waitForFinished()
+    \li QFuture::result()
+    \li QFuture::resultAt()
+    \li QFuture::results()
+    \endlist
+*/
+
+/*!
+    \fn QException::raise() const
+    In your QException subclass, reimplement raise() like this:
+
+    \snippet code/src_corelib_thread_qexception.cpp 2
+*/
+
+/*!
+    \fn QException::clone() const
+    In your QException subclass, reimplement clone() like this:
+
+    \snippet code/src_corelib_thread_qexception.cpp 3
+*/
+
+/*! 
+    \class QUnhandledException
+
+    \brief The UnhandledException class represents an unhandled exception in a worker thread.
+    \since 5.0
+
+    If a worker thread throws an exception that is not a subclass of QException,
+    the Qt functions will throw a QUnhandledException
+    on the receiver thread side.
+
+    Inheriting from this class is not supported.
+*/
+
+/*!
+    \fn QUnhandledException::raise() const
+    \internal
+*/
+
+/*!
+    \fn QUnhandledException::clone() const
+    \internal
+*/
+
+void QException::raise() const
+{
+    QException e = *this;
+    throw e;
+}
+
+QException *QException::clone() const
+{
+    return new QException(*this);
+}
+
+void QUnhandledException::raise() const
+{
+    QUnhandledException e = *this;
+    throw e;
+}
+
+QUnhandledException *QUnhandledException::clone() const
+{
+    return new QUnhandledException(*this);
+}
+
+#ifndef qdoc
+
+namespace QtPrivate {
+
+class Base : public QSharedData
+{
+public:
+    Base(QException *exception)
+    : exception(exception), hasThrown(false) { }
+    ~Base() { delete exception; }
+
+    QException *exception;
+    bool hasThrown;
+};
+
+ExceptionHolder::ExceptionHolder(QException *exception)
+: base(new Base(exception)) {}
+
+ExceptionHolder::ExceptionHolder(const ExceptionHolder &other)
+: base(other.base)
+{}
+
+void ExceptionHolder::operator=(const ExceptionHolder &other)
+{
+    base = other.base;
+}
+
+ExceptionHolder::~ExceptionHolder()
+{}
+
+QException *ExceptionHolder::exception() const
+{
+    return base->exception;
+}
+
+void ExceptionStore::setException(const QException &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 QtPrivate
+
+#endif //qdoc
+
+QT_END_NAMESPACE
+
+#endif // QT_NO_EXCEPTIONS
+#endif // QT_NO_QFUTURE
diff --git a/src/corelib/thread/qexception.h b/src/corelib/thread/qexception.h
new file mode 100644
index 0000000000..7106bb57df
--- /dev/null
+++ b/src/corelib/thread/qexception.h
@@ -0,0 +1,123 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTCORE_QEXCEPTION_H
+#define QTCORE_QEXCEPTION_H
+
+#include <QtCore/qglobal.h>
+
+#ifndef QT_NO_QFUTURE
+
+#include <QtCore/qatomic.h>
+#include <QtCore/qshareddata.h>
+
+#ifndef QT_NO_EXCEPTIONS
+#  include <exception>
+#endif
+
+QT_BEGIN_HEADER
+QT_BEGIN_NAMESPACE
+
+
+#ifndef QT_NO_EXCEPTIONS
+
+class Q_CORE_EXPORT QException : public std::exception
+{
+public:
+    virtual void raise() const;
+    virtual QException *clone() const;
+};
+
+class Q_CORE_EXPORT QUnhandledException : public QException
+{
+public:
+    void raise() const;
+    QUnhandledException *clone() const;
+};
+
+namespace QtPrivate {
+
+class Base;
+class Q_CORE_EXPORT ExceptionHolder
+{
+public:
+    ExceptionHolder(QException *exception = 0);
+    ExceptionHolder(const ExceptionHolder &other);
+    void operator=(const ExceptionHolder &other);
+    ~ExceptionHolder();
+    QException *exception() const;
+    QExplicitlySharedDataPointer<Base> base;
+};
+
+class Q_CORE_EXPORT ExceptionStore
+{
+public:
+    void setException(const QException &e);
+    bool hasException() const;
+    ExceptionHolder exception();
+    void throwPossibleException();
+    bool hasThrown() const;
+    ExceptionHolder exceptionHolder;
+};
+
+} // namespace QtPrivate
+
+#else // QT_NO_EXCEPTIONS
+
+namespace QtPrivate {
+
+class Q_CORE_EXPORT ExceptionStore
+{
+public:
+    ExceptionStore() { }
+    inline void throwPossibleException() const {}
+};
+
+} // namespace QtPrivate
+
+#endif // QT_NO_EXCEPTIONS
+
+QT_END_NAMESPACE
+QT_END_HEADER
+
+#endif // QT_NO_QFUTURE
+
+#endif
diff --git a/src/corelib/thread/thread.pri b/src/corelib/thread/thread.pri
index 7f383d6a4c..215e56628c 100644
--- a/src/corelib/thread/thread.pri
+++ b/src/corelib/thread/thread.pri
@@ -10,6 +10,7 @@ HEADERS += thread/qmutex.h \
            thread/qthreadstorage.h \
            thread/qwaitcondition.h \
            thread/qatomic.h \
+           thread/qexception.h \
            thread/qbasicatomic.h \
            thread/qgenericatomic.h \
            thread/qoldbasicatomic.h
@@ -23,6 +24,7 @@ HEADERS += thread/qmutex_p.h \
            thread/qthreadpool_p.h
 
 SOURCES += thread/qatomic.cpp \
+           thread/qexception.cpp \
            thread/qmutex.cpp \
            thread/qreadwritelock.cpp \
            thread/qrunnable.cpp \