diff options
Diffstat (limited to 'libraries/ode-0.9/ode/src/obstack.cpp')
-rw-r--r-- | libraries/ode-0.9/ode/src/obstack.cpp | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/libraries/ode-0.9/ode/src/obstack.cpp b/libraries/ode-0.9/ode/src/obstack.cpp new file mode 100644 index 0000000..0840396 --- /dev/null +++ b/libraries/ode-0.9/ode/src/obstack.cpp | |||
@@ -0,0 +1,130 @@ | |||
1 | /************************************************************************* | ||
2 | * * | ||
3 | * Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. * | ||
4 | * All rights reserved. Email: russ@q12.org Web: www.q12.org * | ||
5 | * * | ||
6 | * This library is free software; you can redistribute it and/or * | ||
7 | * modify it under the terms of EITHER: * | ||
8 | * (1) The GNU Lesser General Public License as published by the Free * | ||
9 | * Software Foundation; either version 2.1 of the License, or (at * | ||
10 | * your option) any later version. The text of the GNU Lesser * | ||
11 | * General Public License is included with this library in the * | ||
12 | * file LICENSE.TXT. * | ||
13 | * (2) The BSD-style license that is included with this library in * | ||
14 | * the file LICENSE-BSD.TXT. * | ||
15 | * * | ||
16 | * This library is distributed in the hope that it will be useful, * | ||
17 | * but WITHOUT ANY WARRANTY; without even the implied warranty of * | ||
18 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files * | ||
19 | * LICENSE.TXT and LICENSE-BSD.TXT for more details. * | ||
20 | * * | ||
21 | *************************************************************************/ | ||
22 | |||
23 | #include <ode/common.h> | ||
24 | #include <ode/error.h> | ||
25 | #include <ode/memory.h> | ||
26 | #include "obstack.h" | ||
27 | |||
28 | //**************************************************************************** | ||
29 | // macros and constants | ||
30 | |||
31 | #define ROUND_UP_OFFSET_TO_EFFICIENT_SIZE(arena,ofs) \ | ||
32 | ofs = (size_t) (dEFFICIENT_SIZE( ((intP)(arena)) + ofs ) - ((intP)(arena)) ); | ||
33 | |||
34 | #define MAX_ALLOC_SIZE \ | ||
35 | ((size_t)(dOBSTACK_ARENA_SIZE - sizeof (Arena) - EFFICIENT_ALIGNMENT + 1)) | ||
36 | |||
37 | //**************************************************************************** | ||
38 | // dObStack | ||
39 | |||
40 | dObStack::dObStack() | ||
41 | { | ||
42 | first = 0; | ||
43 | last = 0; | ||
44 | current_arena = 0; | ||
45 | current_ofs = 0; | ||
46 | } | ||
47 | |||
48 | |||
49 | dObStack::~dObStack() | ||
50 | { | ||
51 | // free all arenas | ||
52 | Arena *a,*nexta; | ||
53 | a = first; | ||
54 | while (a) { | ||
55 | nexta = a->next; | ||
56 | dFree (a,dOBSTACK_ARENA_SIZE); | ||
57 | a = nexta; | ||
58 | } | ||
59 | } | ||
60 | |||
61 | |||
62 | void *dObStack::alloc (int num_bytes) | ||
63 | { | ||
64 | if ((size_t)num_bytes > MAX_ALLOC_SIZE) dDebug (0,"num_bytes too large"); | ||
65 | |||
66 | // allocate or move to a new arena if necessary | ||
67 | if (!first) { | ||
68 | // allocate the first arena if necessary | ||
69 | first = last = (Arena *) dAlloc (dOBSTACK_ARENA_SIZE); | ||
70 | first->next = 0; | ||
71 | first->used = sizeof (Arena); | ||
72 | ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (first,first->used); | ||
73 | } | ||
74 | else { | ||
75 | // we already have one or more arenas, see if a new arena must be used | ||
76 | if ((last->used + num_bytes) > dOBSTACK_ARENA_SIZE) { | ||
77 | if (!last->next) { | ||
78 | last->next = (Arena *) dAlloc (dOBSTACK_ARENA_SIZE); | ||
79 | last->next->next = 0; | ||
80 | } | ||
81 | last = last->next; | ||
82 | last->used = sizeof (Arena); | ||
83 | ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (last,last->used); | ||
84 | } | ||
85 | } | ||
86 | |||
87 | // allocate an area in the arena | ||
88 | char *c = ((char*) last) + last->used; | ||
89 | last->used += num_bytes; | ||
90 | ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (last,last->used); | ||
91 | return c; | ||
92 | } | ||
93 | |||
94 | |||
95 | void dObStack::freeAll() | ||
96 | { | ||
97 | last = first; | ||
98 | if (first) { | ||
99 | first->used = sizeof(Arena); | ||
100 | ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (first,first->used); | ||
101 | } | ||
102 | } | ||
103 | |||
104 | |||
105 | void *dObStack::rewind() | ||
106 | { | ||
107 | current_arena = first; | ||
108 | current_ofs = sizeof (Arena); | ||
109 | if (current_arena) { | ||
110 | ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (current_arena,current_ofs) | ||
111 | return ((char*) current_arena) + current_ofs; | ||
112 | } | ||
113 | else return 0; | ||
114 | } | ||
115 | |||
116 | |||
117 | void *dObStack::next (int num_bytes) | ||
118 | { | ||
119 | // this functions like alloc, except that no new storage is ever allocated | ||
120 | if (!current_arena) return 0; | ||
121 | current_ofs += num_bytes; | ||
122 | ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (current_arena,current_ofs); | ||
123 | if (current_ofs >= current_arena->used) { | ||
124 | current_arena = current_arena->next; | ||
125 | if (!current_arena) return 0; | ||
126 | current_ofs = sizeof (Arena); | ||
127 | ROUND_UP_OFFSET_TO_EFFICIENT_SIZE (current_arena,current_ofs); | ||
128 | } | ||
129 | return ((char*) current_arena) + current_ofs; | ||
130 | } | ||