72 lines
1.8 KiB
C
72 lines
1.8 KiB
C
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/**
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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 neverFreeMemory.h
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* @author drose
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* @date 2007-06-14
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*/
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#ifndef NEVERFREEMEMORY_H
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#define NEVERFREEMEMORY_H
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#include "dtoolbase.h"
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#include "mutexImpl.h"
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#include <set>
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/**
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* This class is used to allocate bytes of memory from a pool that is never
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* intended to be freed. It is particularly useful to support DeletedChain,
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* which allocates memory in just such a fashion.
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*
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* When it is known that memory will not be freed, it is preferable to use
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* this instead of the standard malloc() (or global_operator_new()) call,
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* since this will help reduce fragmentation problems in the dynamic heap.
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* Also, memory allocated from here will exhibit less wasted space.
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*/
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class EXPCL_DTOOL_DTOOLBASE NeverFreeMemory {
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private:
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NeverFreeMemory();
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public:
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INLINE static void *alloc(size_t size);
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PUBLISHED:
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INLINE static size_t get_total_alloc();
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INLINE static size_t get_total_used();
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INLINE static size_t get_total_unused();
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private:
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void *ns_alloc(size_t size);
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INLINE static NeverFreeMemory *get_global_ptr();
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static void make_global_ptr();
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private:
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class Page {
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public:
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INLINE Page(void *start, size_t size);
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INLINE bool operator < (const Page &other) const;
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INLINE void *alloc(size_t size);
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unsigned char *_next;
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size_t _remaining;
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};
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typedef std::set<Page> Pages;
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Pages _pages;
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size_t _total_alloc;
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size_t _total_used;
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MutexImpl _lock;
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static NeverFreeMemory * TVOLATILE _global_ptr;
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};
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#include "neverFreeMemory.I"
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#endif
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