1/*
2 * SGI FREE SOFTWARE LICENSE B (Version 2.0, Sept. 18, 2008)
3 * Copyright (C) 1991-2000 Silicon Graphics, Inc. All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice including the dates of first publication and
13 * either this permission notice or a reference to
14 * http://oss.sgi.com/projects/FreeB/
15 * shall be included in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * SILICON GRAPHICS, INC. BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
21 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF
22 * OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 *
25 * Except as contained in this notice, the name of Silicon Graphics, Inc.
26 * shall not be used in advertising or otherwise to promote the sale, use or
27 * other dealings in this Software without prior written authorization from
28 * Silicon Graphics, Inc.
29 */
30
31/*
32 * bufpool.h
33 *
34 */
35
36#ifndef __glubufpool_h_
37#define __glubufpool_h_
38
39#include "gluos.h"
40#include "myassert.h"
41#include "mystdlib.h"
42
43#define NBLOCKS	32
44
45class Buffer {
46	friend class 	Pool;
47	Buffer	*	next;		/* next buffer on free list	*/
48};
49
50class Pool {
51public:
52			Pool( int, int, const char * );
53			~Pool( void );
54    inline void*	new_buffer( void );
55    inline void		free_buffer( void * );
56    void		clear( void );
57
58private:
59    void		grow( void );
60
61protected:
62    Buffer		*freelist;		/* linked list of free buffers */
63    char		*blocklist[NBLOCKS];	/* blocks of malloced memory */
64    int			nextblock;		/* next free block index */
65    char		*curblock;		/* last malloced block */
66    int			buffersize;		/* bytes per buffer */
67    int			nextsize;		/* size of next block of memory	*/
68    int			nextfree;		/* byte offset past next free buffer */
69    int			initsize;
70    enum Magic { is_allocated = 0xf3a1, is_free = 0xf1a2 };
71    const char		*name;			/* name of the pool */
72    Magic		magic;			/* marker for valid pool */
73};
74
75/*-----------------------------------------------------------------------------
76 * Pool::free_buffer - return a buffer to a pool
77 *-----------------------------------------------------------------------------
78 */
79
80inline void
81Pool::free_buffer( void *b )
82{
83    assert( (this != 0) && (magic == is_allocated) );
84
85    /* add buffer to singly connected free list */
86
87    ((Buffer *) b)->next = freelist;
88    freelist = (Buffer *) b;
89}
90
91
92/*-----------------------------------------------------------------------------
93 * Pool::new_buffer - allocate a buffer from a pool
94 *-----------------------------------------------------------------------------
95 */
96
97inline void *
98Pool::new_buffer( void )
99{
100    void *buffer;
101
102    assert( (this != 0) && (magic == is_allocated) );
103
104    /* find free buffer */
105
106    if( freelist ) {
107    	buffer = (void *) freelist;
108    	freelist = freelist->next;
109    } else {
110    	if( ! nextfree )
111    	    grow( );
112    	nextfree -= buffersize;;
113    	buffer = (void *) (curblock + nextfree);
114    }
115    return buffer;
116}
117
118class PooledObj {
119public:
120    inline void *	operator new( size_t, Pool & );
121    inline void * 	operator new( size_t, void *);
122    inline void * 	operator new( size_t s)
123				{ return ::new char[s]; }
124    inline void 	operator delete( void * ) { assert( 0 ); }
125    inline void         operator delete( void *, Pool & ) { assert( 0 ); }
126    inline void		deleteMe( Pool & );
127};
128
129inline void *
130PooledObj::operator new( size_t, Pool& pool )
131{
132    return pool.new_buffer();
133}
134
135inline void
136PooledObj::deleteMe( Pool& pool )
137{
138    pool.free_buffer( (void *) this );
139}
140
141#endif /* __glubufpool_h_ */
142