poco/Foundation/include/Poco/ErrorHandler.h

//
// ErrorHandler.h
//
// $Id: //poco/1.4/Foundation/include/Poco/ErrorHandler.h#1 $
//
// Library: Foundation
// Package: Threading
// Module:  ErrorHandler
//
// Definition of the ErrorHandler class.
//
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Foundation_ErrorHandler_INCLUDED
#define Foundation_ErrorHandler_INCLUDED


#include "Poco/Foundation.h"
#include "Poco/Exception.h"
#include "Poco/Mutex.h"


namespace Poco {


class Foundation_API ErrorHandler
	/// This is the base class for thread error handlers.
	///
	/// An unhandled exception that causes a thread to terminate is usually
	/// silently ignored, since the class library cannot do anything meaningful
	/// about it.
	/// 
	/// The Thread class provides the possibility to register a
	/// global ErrorHandler that is invoked whenever a thread has
	/// been terminated by an unhandled exception.
	/// The ErrorHandler must be derived from this class and can
	/// provide implementations of all three exception() overloads.
	///
	/// The ErrorHandler is always invoked within the context of
	/// the offending thread.
{
public:
	ErrorHandler();
		/// Creates the ErrorHandler.

	virtual ~ErrorHandler();
		/// Destroys the ErrorHandler.

	virtual void exception(const Exception& exc);
		/// Called when a Poco::Exception (or a subclass)
		/// caused the thread to terminate.
		///
		/// This method should not throw any exception - it would
		/// be silently ignored.
		///
		/// The default implementation just breaks into the debugger.
		
	virtual void exception(const std::exception& exc);
		/// Called when a std::exception (or a subclass)
		/// caused the thread to terminate.		
		///
		/// This method should not throw any exception - it would
		/// be silently ignored.
		///
		/// The default implementation just breaks into the debugger.

	virtual void exception();
		/// Called when an exception that is neither a
		/// Poco::Exception nor a std::exception caused
		/// the thread to terminate.
		///
		/// This method should not throw any exception - it would
		/// be silently ignored.
		///
		/// The default implementation just breaks into the debugger.
		
	static void handle(const Exception& exc);
		/// Invokes the currently registered ErrorHandler.
		
	static void handle(const std::exception& exc);
		/// Invokes the currently registered ErrorHandler.
	
	static void handle();
		/// Invokes the currently registered ErrorHandler.
	
	static ErrorHandler* set(ErrorHandler* pHandler);
		/// Registers the given handler as the current error handler.
		///
		/// Returns the previously registered handler.

	static ErrorHandler* get();
		/// Returns a pointer to the currently registered
		/// ErrorHandler.

protected:	
	static ErrorHandler* defaultHandler();
		/// Returns the default ErrorHandler.	
		
private:
	static ErrorHandler* _pHandler;
	static FastMutex     _mutex;
};


//
// inlines
//
inline ErrorHandler* ErrorHandler::get()
{
	return _pHandler;
}


} // namespace Poco


#endif // Foundation_ErrorHandler_INCLUDED