src/glu/sgi/libnurbs/internals/bufpool.h

   1 /*
   2 ** License Applicability. Except to the extent portions of this file are
   3 ** made subject to an alternative license as permitted in the SGI Free
   4 ** Software License B, Version 1.1 (the "License"), the contents of this
   5 ** file are subject only to the provisions of the License. You may not use
   6 ** this file except in compliance with the License. You may obtain a copy
   7 ** of the License at Silicon Graphics, Inc., attn: Legal Services, 1600
   8 ** Amphitheatre Parkway, Mountain View, CA 94043-1351, or at:
   9 **
  10 ** http://oss.sgi.com/projects/FreeB
  11 **
  12 ** Note that, as provided in the License, the Software is distributed on an
  13 ** "AS IS" basis, with ALL EXPRESS AND IMPLIED WARRANTIES AND CONDITIONS
  14 ** DISCLAIMED, INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES AND
  15 ** CONDITIONS OF MERCHANTABILITY, SATISFACTORY QUALITY, FITNESS FOR A
  16 ** PARTICULAR PURPOSE, AND NON-INFRINGEMENT.
  17 **
  18 ** Original Code. The Original Code is: OpenGL Sample Implementation,
  19 ** Version 1.2.1, released January 26, 2000, developed by Silicon Graphics,
  20 ** Inc. The Original Code is Copyright (c) 1991-2000 Silicon Graphics, Inc.
  21 ** Copyright in any portions created by third parties is as indicated
  22 ** elsewhere herein. All Rights Reserved.
  23 **
  24 ** Additional Notice Provisions: The application programming interfaces
  25 ** established by SGI in conjunction with the Original Code are The
  26 ** OpenGL(R) Graphics System: A Specification (Version 1.2.1), released
  27 ** April 1, 1999; The OpenGL(R) Graphics System Utility Library (Version
  28 ** 1.3), released November 4, 1998; and OpenGL(R) Graphics with the X
  29 ** Window System(R) (Version 1.3), released October 19, 1998. This software
  30 ** was created using the OpenGL(R) version 1.2.1 Sample Implementation
  31 ** published by SGI, but has not been independently verified as being
  32 ** compliant with the OpenGL(R) version 1.2.1 Specification.
  33 */
  34
  35 /*
  36  * bufpool.h
  37  *
  38  * $Date: 2001/03/17 00:25:40 $ $Revision: 1.1 $
  39  * $Header: /home/krh/git/sync/mesa-cvs-repo/Mesa/src/glu/sgi/libnurbs/internals/bufpool.h,v 1.1 2001/03/17 00:25:40 brianp Exp $
  40  */
  41
  42 #ifndef __glubufpool_h_
  43 #define __glubufpool_h_
  44
  45 #include "myassert.h"
  46 #include "mystdlib.h"
  47
  48 #define NBLOCKS 32
  49
  50 class Buffer {
  51         friend class    Pool;
  52         Buffer  *       next;           /* next buffer on free list     */
  53 };
  54
  55 class Pool {
  56 public:
  57                         Pool( int, int, char * );
  58                         ~Pool( void );
  59     inline void*        new_buffer( void );
  60     inline void         free_buffer( void * );
  61     void                clear( void );
  62
  63 private:
  64     void                grow( void );
  65
  66 protected:
  67     Buffer              *freelist;              /* linked list of free buffers */
  68     char                *blocklist[NBLOCKS];    /* blocks of malloced memory */
  69     int                 nextblock;              /* next free block index */
  70     char                *curblock;              /* last malloced block */
  71     int                 buffersize;             /* bytes per buffer */
  72     int                 nextsize;               /* size of next block of memory */
  73     int                 nextfree;               /* byte offset past next free buffer */
  74     int                 initsize;
  75     enum Magic { is_allocated = 0xf3a1, is_free = 0xf1a2 };
  76     char                *name;                  /* name of the pool */
  77     Magic               magic;                  /* marker for valid pool */
  78 };
  79
  80 /*-----------------------------------------------------------------------------
  81  * Pool::free_buffer - return a buffer to a pool
  82  *-----------------------------------------------------------------------------
  83  */
  84
  85 inline void
  86 Pool::free_buffer( void *b )
  87 {
  88     assert( (this != 0) && (magic == is_allocated) );
  89
  90     /* add buffer to singly connected free list */
  91
  92     ((Buffer *) b)->next = freelist;
  93     freelist = (Buffer *) b;
  94 }
  95
  96
  97 /*-----------------------------------------------------------------------------
  98  * Pool::new_buffer - allocate a buffer from a pool
  99  *-----------------------------------------------------------------------------
 100  */
 101
 102 inline void *
 103 Pool::new_buffer( void )
 104 {
 105     void *buffer;
 106
 107     assert( (this != 0) && (magic == is_allocated) );
 108
 109     /* find free buffer */
 110
 111     if( freelist ) {
 112         buffer = (void *) freelist;
 113         freelist = freelist->next;
 114     } else {
 115         if( ! nextfree )
 116             grow( );
 117         nextfree -= buffersize;;
 118         buffer = (void *) (curblock + nextfree);
 119     }
 120     return buffer;
 121 }
 122
 123 class PooledObj {
 124 public:
 125     inline void *       operator new( size_t, Pool & );
 126     inline void *       operator new( size_t, void *);
 127     inline void *       operator new( size_t s)
 128                                 { return ::new char[s]; }
 129     inline void         operator delete( void * ) { assert( 0 ); }
 130     inline void         deleteMe( Pool & );
 131 };
 132
 133 inline void *
 134 PooledObj::operator new( size_t, Pool& pool )
 135 {
 136     return pool.new_buffer();
 137 }
 138
 139 inline void
 140 PooledObj::deleteMe( Pool& pool )
 141 {
 142     pool.free_buffer( (void *) this );
 143 }
 144
 145 #endif /* __glubufpool_h_ */