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
45 class Buffer {
46 friend class Pool;
47 Buffer * next; /* next buffer on free list */
48 };
49
50 class Pool {
51 public:
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
58 private:
59 void grow( void );
60
61 protected:
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
80 inline void
free_buffer(void * b)81 Pool::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
97 inline void *
new_buffer(void)98 Pool::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
118 class PooledObj {
119 public:
120 inline void * operator new( size_t, Pool & );
121 inline void * operator new( size_t, void *);
new(size_t s)122 inline void * operator new( size_t s)
123 { return ::new char[s]; }
delete(void *)124 inline void operator delete( void * ) { assert( 0 ); }
delete(void *,Pool &)125 inline void operator delete( void *, Pool & ) { assert( 0 ); }
126 inline void deleteMe( Pool & );
127 };
128
129 inline void *
new(size_t,Pool & pool)130 PooledObj::operator new( size_t, Pool& pool )
131 {
132 return pool.new_buffer();
133 }
134
135 inline void
deleteMe(Pool & pool)136 PooledObj::deleteMe( Pool& pool )
137 {
138 pool.free_buffer( (void *) this );
139 }
140
141 #endif /* __glubufpool_h_ */
142