69 lines
2.2 KiB
C++
69 lines
2.2 KiB
C++
/**
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* PANDA 3D SOFTWARE
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* Copyright (c) Carnegie Mellon University. All rights reserved.
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*
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* All use of this software is subject to the terms of the revised BSD
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* license. You should have received a copy of this license along
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* with this source code in a file named "LICENSE."
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*
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* @file cycleDataReader.h
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* @author drose
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* @date 2002-02-21
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*/
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#ifndef CYCLEDATAREADER_H
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#define CYCLEDATAREADER_H
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#include "pandabase.h"
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#include "cycleData.h"
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#include "pipelineCycler.h"
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#include "thread.h"
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/**
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* This template class calls PipelineCycler::read_unlocked(), and then
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* provides a transparent read-only access to the CycleData. It is used to
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* access the data quickly, without holding a lock, for a thread that does not
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* intend to modify the data and write it back out. For cases where the data
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* might be subsequently modified, you should use CycleDataLockedReader.
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*
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* It exists as a syntactic convenience to access the data in the CycleData.
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* It also allows the whole system to compile down to nothing if DO_PIPELINING
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* is not defined.
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*/
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template<class CycleDataType>
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class CycleDataReader {
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public:
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// By hiding this template from interrogate, we improve compile-time speed
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// and memory utilization.
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#ifndef CPPPARSER
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INLINE CycleDataReader(const PipelineCycler<CycleDataType> &cycler,
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Thread *current_thread = Thread::get_current_thread());
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INLINE CycleDataReader(const CycleDataReader<CycleDataType> ©);
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INLINE void operator = (const CycleDataReader<CycleDataType> ©);
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INLINE ~CycleDataReader();
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INLINE const CycleDataType *operator -> () const;
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INLINE operator const CycleDataType * () const;
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INLINE const CycleDataType *p() const;
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INLINE Thread *get_current_thread() const;
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private:
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#ifdef DO_PIPELINING
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// This is the data stored for a real pipelining implementation.
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const PipelineCycler<CycleDataType> *_cycler;
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Thread *_current_thread;
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const CycleDataType *_pointer;
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CycleDataType *_write_pointer;
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#else // !DO_PIPELINING
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// This is all we need for the trivial, do-nothing implementation.
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const CycleDataType *_pointer;
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#endif // DO_PIPELINING
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#endif // CPPPARSER
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};
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#include "cycleDataReader.I"
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#endif
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