source: vis_dev/glu-2.3/src/mem/memrec.c @ 28

Last change on this file since 28 was 13, checked in by cecile, 13 years ago

library glu 2.3

File size: 3.3 KB
Line 
1/* Record manager routines */
2
3
4#include "memint.h"
5
6
7#define ALLOC_SIZE NICE_BLOCK_SIZE
8
9
10/* #define DEBUG_MEM */
11#define MAGIC_COOKIE 0x34f21ab3l
12#define MAGIC_COOKIE1 0x432fa13bl
13
14
15struct list_
16{
17  struct list_ *next;
18};
19
20typedef struct list_ *list;
21
22
23struct rec_mgr_
24{
25  int size;
26  int recs_per_block;
27  list free;
28  list blocks;
29};
30
31
32/* mem_new_rec(mgr) allocates a record from the specified record */
33/* manager. */
34
35pointer
36#if defined(__STDC__)
37mem_new_rec(rec_mgr mgr)
38#else
39mem_new_rec(mgr)
40     rec_mgr mgr;
41#endif
42{
43  int i;
44  pointer p;
45  list new_;
46
47  if (!mgr->free)
48    {
49      /* Allocate a new block. */
50      new_=(list)mem_get_block(ALLOC_SIZE);
51      new_->next=mgr->blocks;
52      mgr->blocks=new_;
53      mgr->free=(list)((INT_PTR)new_+ROUNDUP(sizeof(struct list_)));
54      p=(pointer)(mgr->free);
55      /* Carve the block into pieces. */
56      for (i=1; i < mgr->recs_per_block; ++i)
57        {
58          ((list)p)->next=(list)((INT_PTR)p+mgr->size);
59#if defined(DEBUG_MEM)
60          if (mgr->size >= sizeof(long)+sizeof(struct list_))
61            *(long *)(sizeof(struct list_)+(INT_PTR)p)=MAGIC_COOKIE;
62#endif
63          p=(pointer)((INT_PTR)p+mgr->size);
64        }
65      ((list)p)->next=0;
66#if defined(DEBUG_MEM)
67      if (mgr->size >= sizeof(long)+sizeof(struct list_))
68        *(long *)(sizeof(struct list_)+(INT_PTR)p)=MAGIC_COOKIE;
69#endif
70    }
71  new_=mgr->free;
72#if defined(DEBUG_MEM)
73  if (mgr->size >= sizeof(long)+sizeof(struct list_))
74    if (*(long *)(sizeof(struct list_)+(INT_PTR)new_) != MAGIC_COOKIE)
75      fprintf(stderr, "record at 0x%lx may be in use\n", (INT_PTR)new_);
76    else
77      *(long *)(sizeof(struct list_)+(INT_PTR)new_)=MAGIC_COOKIE1;
78#endif
79  mgr->free=mgr->free->next;
80  return ((pointer)new_);
81}
82
83
84/* mem_free_rec(mgr, rec) frees a record managed by the indicated */
85/* record manager. */
86
87void
88#if defined(__STDC__)
89mem_free_rec(rec_mgr mgr, pointer rec)
90#else
91mem_free_rec(mgr, rec)
92     rec_mgr mgr;
93     pointer rec;
94#endif
95{
96#if defined(DEBUG_MEM)
97  if (mgr->size >= sizeof(long)+sizeof(struct list_))
98    if (*(long *)(sizeof(struct list_)+(INT_PTR)rec) == MAGIC_COOKIE)
99      fprintf(stderr, "record at 0x%lx may already be freed\n", (INT_PTR)rec);
100#endif
101  ((list)rec)->next=mgr->free;
102#if defined(DEBUG_MEM)
103  if (mgr->size >= sizeof(long)+sizeof(struct list_))
104    *(long *)(sizeof(struct list_)+(INT_PTR)rec)=MAGIC_COOKIE;
105#endif
106  mgr->free=(list)rec;
107}
108
109
110/* mem_new_rec_mgr(size) creates a new record manager with the given */
111/* record size. */
112
113rec_mgr
114#if defined(__STDC__)
115mem_new_rec_mgr(int size)
116#else
117mem_new_rec_mgr(size)
118     int size;
119#endif
120{
121  rec_mgr mgr;
122
123  if (size < sizeof(struct list_))
124    size=sizeof(struct list_);
125  size=ROUNDUP(size);
126  if (size > ALLOC_SIZE-ROUNDUP(sizeof(struct list_)))
127    mem_fatal("mem_new_rec_mgr: record size too large");
128  mgr=(rec_mgr)mem_get_block((SIZE_T)sizeof(struct rec_mgr_));
129  mgr->size=size;
130  mgr->recs_per_block=(ALLOC_SIZE-ROUNDUP(sizeof(struct list_)))/size;
131  mgr->free=0;
132  mgr->blocks=0;
133  return (mgr);
134}
135
136
137/* mem_free_rec_mgr(mgr) frees all the storage associated with the */
138/* specified record manager. */
139
140void
141#if defined(__STDC__)
142mem_free_rec_mgr(rec_mgr mgr)
143#else
144mem_free_rec_mgr(mgr)
145     rec_mgr mgr;
146#endif
147{
148  list p, q;
149
150  for (p=mgr->blocks; p; p=q)
151    {
152      q=p->next;
153      mem_free_block((pointer)p);
154    }
155  mem_free_block((pointer)mgr);
156}
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