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c7743d02 | 1 | /* |
cb90e2cb HWN |
2 | * private-gc.h - private declarations for garbage collection. |
3 | * | |
102dbb6f | 4 | * Copyright (C) 2002, 03, 04, 05, 06, 07, 08 Free Software Foundation, Inc. |
cb90e2cb HWN |
5 | * |
6 | * This library is free software; you can redistribute it and/or | |
7 | * modify it under the terms of the GNU Lesser General Public | |
8 | * License as published by the Free Software Foundation; either | |
9 | * version 2.1 of the License, or (at your option) any later version. | |
10 | * | |
11 | * This library is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * Lesser General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU Lesser General Public | |
17 | * License along with this library; if not, write to the Free Software | |
18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | |
19 | */ | |
c7743d02 HWN |
20 | |
21 | #ifndef PRIVATE_GC | |
22 | #define PRIVATE_GC | |
23 | ||
24 | #include "_scm.h" | |
25 | ||
26 | /* {heap tuning parameters} | |
27 | * | |
28 | * These are parameters for controlling memory allocation. The heap | |
29 | * is the area out of which scm_cons, and object headers are allocated. | |
30 | * | |
31 | * Each heap cell is 8 bytes on a 32 bit machine and 16 bytes on a | |
32 | * 64 bit machine. The units of the _SIZE parameters are bytes. | |
33 | * Cons pairs and object headers occupy one heap cell. | |
34 | * | |
35 | * SCM_INIT_HEAP_SIZE is the initial size of heap. If this much heap is | |
36 | * allocated initially the heap will grow by half its current size | |
37 | * each subsequent time more heap is needed. | |
38 | * | |
39 | * If SCM_INIT_HEAP_SIZE heap cannot be allocated initially, SCM_HEAP_SEG_SIZE | |
40 | * will be used, and the heap will grow by SCM_HEAP_SEG_SIZE when more | |
41 | * heap is needed. SCM_HEAP_SEG_SIZE must fit into type size_t. This code | |
42 | * is in scm_init_storage() and alloc_some_heap() in sys.c | |
43 | * | |
44 | * If SCM_INIT_HEAP_SIZE can be allocated initially, the heap will grow by | |
45 | * SCM_EXPHEAP(scm_heap_size) when more heap is needed. | |
46 | * | |
47 | * SCM_MIN_HEAP_SEG_SIZE is minimum size of heap to accept when more heap | |
48 | * is needed. | |
49 | */ | |
50 | ||
51 | ||
52 | /* | |
53 | * Heap size 45000 and 40% min yield gives quick startup and no extra | |
54 | * heap allocation. Having higher values on min yield may lead to | |
55 | * large heaps, especially if code behaviour is varying its | |
56 | * maximum consumption between different freelists. | |
57 | */ | |
58 | ||
59 | /* | |
60 | These values used to be global C variables. However, they're also | |
61 | available through the environment, and having a double interface is | |
62 | confusing. Now they're #defines --hwn. | |
63 | */ | |
64 | ||
65 | #define SCM_DEFAULT_INIT_HEAP_SIZE_1 256*1024 | |
66 | #define SCM_DEFAULT_MIN_YIELD_1 40 | |
67 | #define SCM_DEFAULT_INIT_HEAP_SIZE_2 32*1024 | |
68 | ||
69 | /* The following value may seem large, but note that if we get to GC at | |
70 | * all, this means that we have a numerically intensive application | |
71 | */ | |
72 | #define SCM_DEFAULT_MIN_YIELD_2 40 | |
322a2bf7 MV |
73 | |
74 | #define SCM_DEFAULT_MAX_SEGMENT_SIZE (20*1024*1024L) | |
c7743d02 | 75 | |
c7743d02 HWN |
76 | #define SCM_MIN_HEAP_SEG_SIZE (8 * SCM_GC_SIZEOF_CARD) |
77 | #define SCM_HEAP_SEG_SIZE (16384L * sizeof (scm_t_cell)) | |
78 | ||
1383773b | 79 | #define SCM_DOUBLECELL_ALIGNED_P(x) (((2 * sizeof (scm_t_cell) - 1) & SCM_UNPACK (x)) == 0) |
c7743d02 HWN |
80 | |
81 | ||
1383773b HWN |
82 | #define SCM_GC_CARD_BVEC_SIZE_IN_LONGS \ |
83 | ((SCM_GC_CARD_N_CELLS + SCM_C_BVEC_LONG_BITS - 1) / SCM_C_BVEC_LONG_BITS) | |
84 | #define SCM_GC_IN_CARD_HEADERP(x) \ | |
85 | (scm_t_cell *) (x) < SCM_GC_CELL_CARD (x) + SCM_GC_CARD_N_HEADER_CELLS | |
c7743d02 HWN |
86 | |
87 | ||
88 | int scm_getenv_int (const char *var, int def); | |
89 | ||
90 | ||
91 | typedef enum { return_on_error, abort_on_error } policy_on_error; | |
92 | ||
93 | /* gc-freelist*/ | |
94 | ||
95 | /* | |
96 | FREELIST: | |
97 | ||
98 | A struct holding GC statistics on a particular type of cells. | |
99 | */ | |
100 | typedef struct scm_t_cell_type_statistics { | |
c7743d02 HWN |
101 | /* |
102 | heap segment where the last cell was allocated | |
103 | */ | |
104 | int heap_segment_idx; | |
105 | ||
106 | /* minimum yield on this list in order not to grow the heap | |
107 | */ | |
108 | long min_yield; | |
109 | ||
110 | /* defines min_yield as percent of total heap size | |
111 | */ | |
112 | int min_yield_fraction; | |
113 | ||
114 | /* number of cells per object on this list */ | |
115 | int span; | |
116 | ||
117 | /* number of collected cells during last GC */ | |
118 | unsigned long collected; | |
119 | ||
120 | /* number of collected cells during penultimate GC */ | |
121 | unsigned long collected_1; | |
122 | ||
123 | /* total number of cells in heap segments | |
124 | * belonging to this list. | |
125 | */ | |
126 | unsigned long heap_size; | |
127 | ||
c2cbcc57 | 128 | |
c7743d02 HWN |
129 | } scm_t_cell_type_statistics; |
130 | ||
131 | ||
4c7016dc HWN |
132 | /* Sweep statistics. */ |
133 | typedef struct scm_sweep_statistics | |
134 | { | |
135 | /* Number of cells "swept", i.e., visited during the sweep operation. */ | |
136 | unsigned swept; | |
137 | ||
138 | /* Number of cells collected during the sweep operation. This number must | |
139 | alsways be lower than or equal to SWEPT. */ | |
140 | unsigned collected; | |
141 | } scm_t_sweep_statistics; | |
142 | ||
143 | #define scm_i_sweep_statistics_init(_stats) \ | |
144 | do \ | |
145 | { \ | |
146 | (_stats)->swept = (_stats)->collected = 0; \ | |
147 | } \ | |
148 | while (0) | |
149 | ||
150 | #define scm_i_sweep_statistics_sum(_sum, _addition) \ | |
151 | do \ | |
152 | { \ | |
153 | (_sum)->swept += (_addition).swept; \ | |
154 | (_sum)->collected += (_addition).collected; \ | |
155 | } \ | |
156 | while (0) | |
157 | ||
4c7016dc | 158 | \f |
c7743d02 HWN |
159 | extern scm_t_cell_type_statistics scm_i_master_freelist; |
160 | extern scm_t_cell_type_statistics scm_i_master_freelist2; | |
c7743d02 | 161 | |
102dbb6f | 162 | SCM_INTERNAL |
4c7016dc | 163 | void scm_i_adjust_min_yield (scm_t_cell_type_statistics *freelist, |
d9f71a07 LC |
164 | scm_t_sweep_statistics sweep_stats, |
165 | scm_t_sweep_statistics sweep_stats_1); | |
102dbb6f | 166 | SCM_INTERNAL |
c7743d02 | 167 | void scm_i_gc_sweep_freelist_reset (scm_t_cell_type_statistics *freelist); |
102dbb6f | 168 | SCM_INTERNAL |
c7743d02 | 169 | int scm_i_gc_grow_heap_p (scm_t_cell_type_statistics * freelist); |
dac04e9f HWN |
170 | |
171 | ||
c7743d02 HWN |
172 | #define SCM_HEAP_SIZE \ |
173 | (scm_i_master_freelist.heap_size + scm_i_master_freelist2.heap_size) | |
174 | ||
175 | ||
176 | #define SCM_MAX(A, B) ((A) > (B) ? (A) : (B)) | |
177 | #define SCM_MIN(A, B) ((A) < (B) ? (A) : (B)) | |
178 | ||
d3774e2c MV |
179 | /* CELL_P checks a random word whether it has the right form for a |
180 | pointer to a cell. Use scm_i_find_heap_segment_containing_object | |
181 | to find out whether it actually points to a real cell. | |
182 | ||
183 | The right form for a cell pointer is this: the low three bits must | |
184 | be scm_tc3_cons, and when the scm_tc3_cons tag is stripped, the | |
185 | resulting pointer must be correctly aligned. | |
186 | scm_i_initialize_heap_segment_data guarantees that the test below | |
187 | works. | |
188 | */ | |
189 | #define CELL_P(x) ((SCM_UNPACK(x) & (sizeof(scm_t_cell)-1)) == scm_tc3_cons) | |
c7743d02 HWN |
190 | |
191 | /* | |
192 | gc-mark | |
193 | */ | |
c7743d02 HWN |
194 | void scm_mark_all (void); |
195 | ||
c7743d02 HWN |
196 | /* |
197 | gc-segment: | |
198 | */ | |
199 | ||
c7743d02 HWN |
200 | /* |
201 | ||
202 | Cells are stored in a heap-segment: it is a contiguous chunk of | |
203 | memory, that associated with one freelist. | |
204 | */ | |
c7743d02 HWN |
205 | typedef struct scm_t_heap_segment |
206 | { | |
207 | /* | |
208 | {lower, upper} bounds of the segment | |
209 | ||
210 | The upper bound is also the start of the mark space. | |
211 | */ | |
212 | scm_t_cell *bounds[2]; | |
213 | ||
214 | /* | |
215 | If we ever decide to give it back, we could do it with this ptr. | |
216 | ||
217 | Note that giving back memory is not very useful; as long we don't | |
218 | touch a chunk of memory, the virtual memory system will keep it | |
219 | swapped out. We could simply forget about a block. | |
220 | ||
221 | (not that we do that, but anyway.) | |
222 | */ | |
223 | ||
224 | void* malloced; | |
225 | ||
226 | scm_t_cell * next_free_card; | |
227 | ||
228 | /* address of the head-of-freelist pointer for this segment's cells. | |
229 | All segments usually point to the same one, scm_i_freelist. */ | |
230 | scm_t_cell_type_statistics *freelist; | |
231 | ||
232 | /* number of cells per object in this segment */ | |
233 | int span; | |
234 | ||
235 | ||
236 | /* | |
237 | Is this the first time that the cells are accessed? | |
238 | */ | |
239 | int first_time; | |
240 | ||
241 | } scm_t_heap_segment; | |
242 | ||
243 | ||
244 | ||
245 | /* | |
c7743d02 HWN |
246 | A table of segment records is kept that records the upper and |
247 | lower extents of the segment; this is used during the conservative | |
248 | phase of gc to identify probably gc roots (because they point | |
249 | into valid segments at reasonable offsets). | |
c7743d02 HWN |
250 | */ |
251 | extern scm_t_heap_segment ** scm_i_heap_segment_table; | |
252 | extern size_t scm_i_heap_segment_table_size; | |
253 | ||
254 | ||
102dbb6f LC |
255 | SCM_INTERNAL int scm_i_init_card_freelist (scm_t_cell * card, SCM *free_list, |
256 | scm_t_heap_segment*); | |
257 | SCM_INTERNAL int scm_i_sweep_card (scm_t_cell *card, SCM *free_list, | |
258 | scm_t_heap_segment *); | |
259 | SCM_INTERNAL void scm_i_card_statistics (scm_t_cell *p, SCM hashtab, | |
260 | scm_t_heap_segment *seg); | |
261 | SCM_INTERNAL char const *scm_i_tag_name (scm_t_bits tag); /* MOVEME */ | |
262 | ||
263 | SCM_INTERNAL int scm_i_initialize_heap_segment_data (scm_t_heap_segment *seg, | |
264 | size_t requested); | |
265 | SCM_INTERNAL int scm_i_segment_card_count (scm_t_heap_segment *seg); | |
266 | SCM_INTERNAL int scm_i_segment_cell_count (scm_t_heap_segment *seg); | |
267 | ||
268 | SCM_INTERNAL void scm_i_clear_segment_mark_space (scm_t_heap_segment *seg); | |
269 | SCM_INTERNAL scm_t_heap_segment * | |
270 | scm_i_make_empty_heap_segment (scm_t_cell_type_statistics*); | |
271 | SCM_INTERNAL SCM scm_i_sweep_some_cards (scm_t_heap_segment *seg, | |
272 | scm_t_sweep_statistics *sweep_stats); | |
273 | SCM_INTERNAL void scm_i_sweep_segment (scm_t_heap_segment *seg, | |
274 | scm_t_sweep_statistics *sweep_stats); | |
275 | ||
276 | SCM_INTERNAL void scm_i_heap_segment_statistics (scm_t_heap_segment *seg, | |
277 | SCM tab); | |
278 | ||
279 | ||
280 | SCM_INTERNAL int scm_i_insert_segment (scm_t_heap_segment *seg); | |
281 | SCM_INTERNAL long int scm_i_find_heap_segment_containing_object (SCM obj); | |
282 | SCM_INTERNAL int scm_i_get_new_heap_segment (scm_t_cell_type_statistics *, | |
283 | scm_t_sweep_statistics, | |
284 | policy_on_error); | |
285 | SCM_INTERNAL void scm_i_clear_mark_space (void); | |
286 | SCM_INTERNAL void scm_i_sweep_segments (void); | |
287 | SCM_INTERNAL SCM scm_i_sweep_some_segments (scm_t_cell_type_statistics *fl, | |
288 | scm_t_sweep_statistics *sweep_stats); | |
289 | SCM_INTERNAL void scm_i_reset_segments (void); | |
290 | SCM_INTERNAL void scm_i_sweep_all_segments (char const *reason, | |
291 | scm_t_sweep_statistics *sweep_stats); | |
292 | SCM_INTERNAL SCM scm_i_all_segments_statistics (SCM hashtab); | |
293 | SCM_INTERNAL void scm_i_make_initial_segment (int init_heap_size, | |
294 | scm_t_cell_type_statistics *fl); | |
c7743d02 HWN |
295 | |
296 | extern long int scm_i_deprecated_memory_return; | |
297 | ||
c7743d02 HWN |
298 | /* |
299 | global init funcs. | |
300 | */ | |
301 | void scm_gc_init_malloc (void); | |
302 | void scm_gc_init_freelist (void); | |
303 | void scm_gc_init_segments (void); | |
304 | void scm_gc_init_mark (void); | |
eab1b259 HWN |
305 | |
306 | ||
c7743d02 | 307 | #endif |