topical media & game development
lib-of-vs-libs-Poco-include-Poco-ActiveResult.h / h
//
// ActiveResult.h
//
//
//
// Library: Foundation
// Package: Threading
// Module: ActiveObjects
//
// Definition of the ActiveResult class.
//
// Copyright (c) 2004-2007, 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_ActiveResult_INCLUDED
define Foundation_ActiveResult_INCLUDED
include "Poco/Foundation.h"
include "Poco/Mutex.h"
include "Poco/Event.h"
include "Poco/RefCountedObject.h"
include "Poco/Exception.h"
include <algorithm>
namespace Poco {
template <class ResultType>
class ActiveResultHolder: public RefCountedObject
This class holds the result of an asynchronous method
invocation. It is used to pass the result from the
execution thread back to the invocation thread.
The class uses reference counting for memory management.
Do not use this class directly, use ActiveResult instead.
{
public:
ActiveResultHolder():
_pData(0),
_pExc(0),
_event(false)
Creates an ActiveResultHolder.
{
}
ResultType& data()
Returns a reference to the actual result.
{
poco_check_ptr(_pData);
return *_pData;
}
void data(ResultType* pData)
{
delete _pData;
_pData = pData;
}
void wait()
Pauses the caller until the result becomes available.
{
_event.wait();
}
bool tryWait(long milliseconds)
Waits up to the specified interval for the result to
become available. Returns true if the result became
available, false otherwise.
{
return _event.tryWait(milliseconds);
}
void wait(long milliseconds)
Waits up to the specified interval for the result to
become available. Throws a TimeoutException if the
result did not became available.
{
_event.wait(milliseconds);
}
void notify()
Notifies the invoking thread that the result became available.
{
_event.set();
}
bool failed() const
Returns true if the active method failed (and threw an exception).
Information about the exception can be obtained by calling error().
{
return _pExc != 0;
}
std::string error() const
If the active method threw an exception, a textual representation
of the exception is returned. An empty string is returned if the
active method completed successfully.
{
if (_pExc)
return _pExc->message();
else
return std::string();
}
Exception* exception() const
If the active method threw an exception, a clone of the exception
object is returned, otherwise null.
{
return _pExc;
}
void error(const Exception& exc)
Sets the exception.
{
delete _pExc;
_pExc = exc.clone();
}
void error(const std::string& msg)
Sets the exception.
{
delete _pExc;
_pExc = new UnhandledException(msg);
}
protected:
~ActiveResultHolder()
{
delete _pData;
delete _pExc;
}
private:
ResultType* _pData;
Exception* _pExc;
Event _event;
};
template <>
class ActiveResultHolder: public RefCountedObject
{
public:
ActiveResultHolder():
_pExc(0),
_event(false)
Creates an ActiveResultHolder.
{
}
void wait()
Pauses the caller until the result becomes available.
{
_event.wait();
}
bool tryWait(long milliseconds)
Waits up to the specified interval for the result to
become available. Returns true if the result became
available, false otherwise.
{
return _event.tryWait(milliseconds);
}
void wait(long milliseconds)
Waits up to the specified interval for the result to
become available. Throws a TimeoutException if the
result did not became available.
{
_event.wait(milliseconds);
}
void notify()
Notifies the invoking thread that the result became available.
{
_event.set();
}
bool failed() const
Returns true if the active method failed (and threw an exception).
Information about the exception can be obtained by calling error().
{
return _pExc != 0;
}
std::string error() const
If the active method threw an exception, a textual representation
of the exception is returned. An empty string is returned if the
active method completed successfully.
{
if (_pExc)
return _pExc->message();
else
return std::string();
}
Exception* exception() const
If the active method threw an exception, a clone of the exception
object is returned, otherwise null.
{
return _pExc;
}
void error(const Exception& exc)
Sets the exception.
{
delete _pExc;
_pExc = exc.clone();
}
void error(const std::string& msg)
Sets the exception.
{
delete _pExc;
_pExc = new UnhandledException(msg);
}
protected:
~ActiveResultHolder()
{
delete _pExc;
}
private:
Exception* _pExc;
Event _event;
};
template <class RT>
class ActiveResult
This class holds the result of an asynchronous method
invocation (see class ActiveMethod). It is used to pass the
result from the execution thread back to the invocation thread.
{
public:
typedef RT ResultType;
typedef ActiveResultHolder<ResultType> ActiveResultHolderType;
ActiveResult(ActiveResultHolderType* pHolder):
_pHolder(pHolder)
Creates the active result. For internal use only.
{
poco_check_ptr (pHolder);
}
ActiveResult(const ActiveResult& result)
Copy constructor.
{
_pHolder = result._pHolder;
_pHolder->duplicate();
}
~ActiveResult()
Destroys the result.
{
_pHolder->release();
}
ActiveResult& operator = (const ActiveResult& result)
Assignment operator.
{
ActiveResult tmp(result);
swap(tmp);
return *this;
}
void swap(ActiveResult& result)
{
using std::swap;
swap(_pHolder, result._pHolder);
}
ResultType& data() const
Returns a reference to the result data.
{
return _pHolder->data();
}
void data(ResultType* pValue)
{
_pHolder->data(pValue);
}
void wait()
Pauses the caller until the result becomes available.
{
_pHolder->wait();
}
bool tryWait(long milliseconds)
Waits up to the specified interval for the result to
become available. Returns true if the result became
available, false otherwise.
{
return _pHolder->tryWait(milliseconds);
}
void wait(long milliseconds)
Waits up to the specified interval for the result to
become available. Throws a TimeoutException if the
result did not became available.
{
_pHolder->wait(milliseconds);
}
bool available() const
Returns true if a result is available.
{
return _pHolder->tryWait(0);
}
bool failed() const
Returns true if the active method failed (and threw an exception).
Information about the exception can be obtained by calling error().
{
return _pHolder->failed();
}
std::string error() const
If the active method threw an exception, a textual representation
of the exception is returned. An empty string is returned if the
active method completed successfully.
{
return _pHolder->error();
}
Exception* exception() const
If the active method threw an exception, a clone of the exception
object is returned, otherwise null.
{
return _pHolder->exception();
}
void notify()
Notifies the invoking thread that the result became available.
For internal use only.
{
_pHolder->notify();
}
ResultType& data()
Returns a non-const reference to the result data. For internal
use only.
{
return _pHolder->data();
}
void error(const std::string& msg)
Sets the failed flag and the exception message.
{
_pHolder->error(msg);
}
void error(const Exception& exc)
Sets the failed flag and the exception message.
{
_pHolder->error(exc);
}
private:
ActiveResult();
ActiveResultHolderType* _pHolder;
};
template <>
class ActiveResult
This class holds the result of an asynchronous method
invocation (see class ActiveMethod). It is used to pass the
result from the execution thread back to the invocation thread.
{
public:
typedef ActiveResultHolder
<void> ActiveResultHolderType;
ActiveResult(ActiveResultHolderType* pHolder):
_pHolder(pHolder)
Creates the active result. For internal use only.
{
poco_check_ptr (pHolder);
}
ActiveResult(const ActiveResult& result)
Copy constructor.
{
_pHolder = result._pHolder;
_pHolder->duplicate();
}
~ActiveResult()
Destroys the result.
{
_pHolder->release();
}
ActiveResult& operator = (const ActiveResult& result)
Assignment operator.
{
ActiveResult tmp(result);
swap(tmp);
return *this;
}
void swap(ActiveResult& result)
{
using std::swap;
swap(_pHolder, result._pHolder);
}
void wait()
Pauses the caller until the result becomes available.
{
_pHolder->wait();
}
bool tryWait(long milliseconds)
Waits up to the specified interval for the result to
become available. Returns true if the result became
available, false otherwise.
{
return _pHolder->tryWait(milliseconds);
}
void wait(long milliseconds)
Waits up to the specified interval for the result to
become available. Throws a TimeoutException if the
result did not became available.
{
_pHolder->wait(milliseconds);
}
bool available() const
Returns true if a result is available.
{
return _pHolder->tryWait(0);
}
bool failed() const
Returns true if the active method failed (and threw an exception).
Information about the exception can be obtained by calling error().
{
return _pHolder->failed();
}
std::string error() const
If the active method threw an exception, a textual representation
of the exception is returned. An empty string is returned if the
active method completed successfully.
{
return _pHolder->error();
}
Exception* exception() const
If the active method threw an exception, a clone of the exception
object is returned, otherwise null.
{
return _pHolder->exception();
}
void notify()
Notifies the invoking thread that the result became available.
For internal use only.
{
_pHolder->notify();
}
void error(const std::string& msg)
Sets the failed flag and the exception message.
{
_pHolder->error(msg);
}
void error(const Exception& exc)
Sets the failed flag and the exception message.
{
_pHolder->error(exc);
}
private:
ActiveResult();
ActiveResultHolderType* _pHolder;
};
} // namespace Poco
endif // Foundation_ActiveResult_INCLUDED
(C) Æliens
04/09/2009
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