aboutsummaryrefslogtreecommitdiffstats
path: root/src/glu/sgi/libnurbs/internals/bufpool.h
blob: 0fa9433750cd8948a656af7e28960b45d5a98131 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
/*
 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice including the dates of first publication and
 * either this permission notice or a reference to
 * http://oss.sgi.com/projects/FreeB/
 * shall be included in all copies or substantial portions of the Software.
 *
 * 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 AND NONINFRINGEMENT. IN NO EVENT SHALL
 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Except as contained in this notice, the name of Silicon Graphics, Inc.
 * shall not be used in advertising or otherwise to promote the sale, use or
 * other dealings in this Software without prior written authorization from
 * Silicon Graphics, Inc.
 */

/*
 * bufpool.h
 *
 */

#ifndef __glubufpool_h_
#define __glubufpool_h_

#include "gluos.h"
#include "myassert.h"
#include "mystdlib.h"

#define NBLOCKS	32

class Buffer {
	friend class 	Pool;
	Buffer	*	next;		/* next buffer on free list	*/
};

class Pool {
public:
			Pool( int, int, const char * );
			~Pool( void );
    inline void*	new_buffer( void );
    inline void		free_buffer( void * );
    void		clear( void );
    
private:
    void		grow( void );

protected:
    Buffer		*freelist;		/* linked list of free buffers */
    char		*blocklist[NBLOCKS];	/* blocks of malloced memory */
    int			nextblock;		/* next free block index */
    char		*curblock;		/* last malloced block */
    int			buffersize;		/* bytes per buffer */
    int			nextsize;		/* size of next block of memory	*/
    int			nextfree;		/* byte offset past next free buffer */
    int			initsize;
    enum Magic { is_allocated = 0xf3a1, is_free = 0xf1a2 };
    const char		*name;			/* name of the pool */
    Magic		magic;			/* marker for valid pool */
};

/*-----------------------------------------------------------------------------
 * Pool::free_buffer - return a buffer to a pool
 *-----------------------------------------------------------------------------
 */

inline void
Pool::free_buffer( void *b )
{
    assert( (this != 0) && (magic == is_allocated) );

    /* add buffer to singly connected free list */

    ((Buffer *) b)->next = freelist;
    freelist = (Buffer *) b;
}


/*-----------------------------------------------------------------------------
 * Pool::new_buffer - allocate a buffer from a pool
 *-----------------------------------------------------------------------------
 */

inline void * 
Pool::new_buffer( void )
{
    void *buffer;

    assert( (this != 0) && (magic == is_allocated) );

    /* find free buffer */

    if( freelist ) {
    	buffer = (void *) freelist; 
    	freelist = freelist->next;
    } else {
    	if( ! nextfree )
    	    grow( );
    	nextfree -= buffersize;;
    	buffer = (void *) (curblock + nextfree);
    }
    return buffer;
}
	
class PooledObj {
public:
    inline void *	operator new( size_t, Pool & );
    inline void * 	operator new( size_t, void *);
    inline void * 	operator new( size_t s)
				{ return ::new char[s]; }
    inline void 	operator delete( void * ) { assert( 0 ); }
    inline void         operator delete( void *, Pool & ) { assert( 0 ); }
    inline void		deleteMe( Pool & );
};

inline void *
PooledObj::operator new( size_t, Pool& pool )
{
    return pool.new_buffer();
}

inline void
PooledObj::deleteMe( Pool& pool )
{
    pool.free_buffer( (void *) this );
}

#endif /* __glubufpool_h_ */