usr/src/lib/libbc/libc/gen/common/mallint.h

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 #pragma ident   "%Z%%M% %I%     %E% SMI"
  23
  24 /*
  25  * Copyright (c) 1986 by Sun Microsystems, Inc.
  26  */
  27
  28 /*
  29  * file: mallint.h
  30  * description:
  31  *
  32  * Definitions for malloc.c and friends (realloc.c, memalign.c)
  33  *
  34  * The node header structure.  Header info never overlaps with user
  35  * data space, in order to accommodate the following atrocity:
  36  *              free(p);
  37  *              realloc(p, newsize);
  38  * ... which was historically used to obtain storage compaction as
  39  * a side effect of the realloc() call, when the block referenced
  40  * by p was coalesced with another free block by the call to free().
  41  *
  42  * To reduce storage consumption, a header block is associated with
  43  * free blocks only, not allocated blocks.
  44  * When a free block is allocated, its header block is put on
  45  * a free header block list.
  46  *
  47  * This creates a header space and a free block space.
  48  * The left pointer of a header blocks is used to chain free header
  49  * blocks together.  New header blocks are allocated in chunks of
  50  * NFREE_HDRS.
  51  */
  52 #include <malloc.h>
  53
  54 typedef enum {false,true} bool;
  55 typedef struct  freehdr *Freehdr;
  56 typedef struct  dblk    *Dblk;
  57 typedef unsigned int    uint;
  58
  59 /*
  60  * Description of a header for a free block
  61  * Only free blocks have such headers.
  62  */
  63 struct  freehdr {
  64         Freehdr left;                   /* Left tree pointer */
  65         Freehdr right;                  /* Right tree pointer */
  66         Dblk    block;                  /* Ptr to the data block */
  67         uint    size;
  68 };
  69
  70 #define NIL             ((Freehdr) 0)
  71 #define NFREE_HDRS      512             /* Get this many headers at a time */
  72 #define SMALLEST_BLK    sizeof(struct dblk)     /* Size of smallest block */
  73 #define NULL            0
  74
  75 /*
  76  * Description of a data block.
  77  * A data block consists of a length word, possibly followed by
  78  * a filler word for alignment, followed by the user's data.
  79  * To back up from the user's data to the length word, use
  80  * (address of data) - ALIGNSIZ;
  81  */
  82
  83 #ifdef sparc
  84 #define ALIGNSIZ        sizeof(double)
  85 struct  dblk    {
  86         uint    size;                   /* Size of the block */
  87         uint    filler;                 /* filler, for double alignment */
  88         char    data[ALIGNSIZ];         /* Addr returned to the caller */
  89 };
  90 #endif
  91
  92 #ifdef mc68000
  93 #define ALIGNSIZ        sizeof(uint)
  94 struct  dblk    {
  95         uint    size;                   /* Size of the block */
  96         char    data[ALIGNSIZ];         /* Addr returned to the caller */
  97 };
  98 #endif
  99
 100
 101 /*
 102  * weight(x) is the size of a block, in bytes; or 0 if and only if x
 103  *      is a null pointer.  Note that malloc() and free() should be
 104  *      prepared to deal with things like zero-length blocks, which
 105  *      can be introduced by errant programs.
 106  */
 107
 108 #define weight(x)       ((x) == NIL? 0: (x->size))
 109 #define roundup(x, y)   ((((x)+((y)-1))/(y))*(y))
 110 #define nextblk(p, size) ((Dblk) ((char *) (p) + (size)))
 111 #define max(a, b)       ((a) < (b)? (b): (a))
 112 #define min(a, b)       ((a) < (b)? (a): (b))
 113 #define heapsize()      (_ubound - _lbound)
 114 #define misaligned(p)   ((unsigned)(p)&3)
 115
 116 extern  Freehdr _root;
 117 extern  char    *_lbound, *_ubound;
 118 extern  int     malloc_debug();
 119
 120 extern  struct mallinfo __mallinfo;