QtConcurrent::Exception Class Reference

The Exception class provides a base class for exceptions that can transferred across threads. More...

#include <qtconcurrentexception.h>

Inheritance diagram for QtConcurrent::Exception:

Public Functions
virtual Exception *	clone () const
	In your QtConcurrent::Exception subclass, reimplement clone() like this: More...
virtual void	raise () const
	In your QtConcurrent::Exception subclass, reimplement raise() like this: More...

Detailed Description

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:

class MyException : public QtConcurrent::Exception
{
public:
    void raise() const { throw *this; }
    Exception *clone() const { return new MyException(*this); }
};

QtConcurrent::Exception subclasses must be thrown by value and caught by reference:

try  {
    QtConcurrent::blockingMap(list, throwFunction); // throwFunction throws MyException
} catch (MyException &e) {
    // handle exception
}

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:

• QFuture::waitForFinished()
• QFuture::result()
• QFuture::resultAt()
• QFuture::results()

Definition at line 65 of file qtconcurrentexception.h.

Functions

clone()

Exception * QtConcurrent::Exception::clone ( ) const

virtual

In your QtConcurrent::Exception subclass, reimplement clone() like this:

MyException *MyException::clone() const { return new MyException(*this); }

Reimplemented in QtConcurrent::UnhandledException.

Definition at line 134 of file qtconcurrentexception.cpp.

Referenced by QtConcurrent::UnhandledException::clone().

{
    return new Exception(*this);
}

raise()

void QtConcurrent::Exception::raise ( ) const

virtual

In your QtConcurrent::Exception subclass, reimplement raise() like this:

void MyException::raise() const { throw *this; }

Reimplemented in QtConcurrent::UnhandledException.

Definition at line 128 of file qtconcurrentexception.cpp.

{
    Exception e = *this;
    throw e;
}

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The documentation for this class was generated from the following files:

• /src/corelib/concurrent/qtconcurrentexception.h
• /src/corelib/concurrent/qtconcurrentexception.cpp