panda3d/panda/src/pipeline/cycleDataReader.h
2008-05-28 18:37:20 +00:00

75 lines
2.6 KiB
C++

// Filename: cycleDataReader.h
// Created by: drose (21Feb02)
//
////////////////////////////////////////////////////////////////////
//
// PANDA 3D SOFTWARE
// Copyright (c) Carnegie Mellon University. All rights reserved.
//
// All use of this software is subject to the terms of the revised BSD
// license. You should have received a copy of this license along
// with this source code in a file named "LICENSE."
//
////////////////////////////////////////////////////////////////////
#ifndef CYCLEDATAREADER_H
#define CYCLEDATAREADER_H
#include "pandabase.h"
#include "cycleData.h"
#include "pipelineCycler.h"
#include "thread.h"
////////////////////////////////////////////////////////////////////
// Class : CycleDataReader
// Description : This template class calls
// PipelineCycler::read_unlocked(), and then provides a
// transparent read-only access to the CycleData. It is
// used to access the data quickly, without holding a
// lock, for a thread that does not intend to modify the
// data and write it back out. For cases where the data
// might be subsequently modified, you should use
// CycleDataLockedReader.
//
// It exists as a syntactic convenience to access the
// data in the CycleData. It also allows the whole
// system to compile down to nothing if
// SUPPORT_PIPELINING is not defined.
////////////////////////////////////////////////////////////////////
template<class CycleDataType>
class CycleDataReader {
public:
// By hiding this template from interrogate, we improve compile-time
// speed and memory utilization.
#ifndef CPPPARSER
INLINE CycleDataReader(const PipelineCycler<CycleDataType> &cycler,
Thread *current_thread = Thread::get_current_thread());
INLINE CycleDataReader(const CycleDataReader<CycleDataType> &copy);
INLINE void operator = (const CycleDataReader<CycleDataType> &copy);
INLINE ~CycleDataReader();
INLINE const CycleDataType *operator -> () const;
INLINE operator const CycleDataType * () const;
INLINE Thread *get_current_thread() const;
private:
#ifdef DO_PIPELINING
// This is the data stored for a real pipelining implementation.
const PipelineCycler<CycleDataType> *_cycler;
Thread *_current_thread;
const CycleDataType *_pointer;
CycleDataType *_write_pointer;
#else // !DO_PIPELINING
// This is all we need for the trivial, do-nothing implementation.
const CycleDataType *_pointer;
#endif // DO_PIPELINING
#endif // CPPPARSER
};
#include "cycleDataReader.I"
#endif