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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 HWN |
75 | |
76 | ||
77 | ||
78 | #define SCM_MIN_HEAP_SEG_SIZE (8 * SCM_GC_SIZEOF_CARD) | |
79 | #define SCM_HEAP_SEG_SIZE (16384L * sizeof (scm_t_cell)) | |
80 | ||
81 | ||
1383773b | 82 | #define SCM_DOUBLECELL_ALIGNED_P(x) (((2 * sizeof (scm_t_cell) - 1) & SCM_UNPACK (x)) == 0) |
c7743d02 HWN |
83 | |
84 | ||
1383773b HWN |
85 | #define SCM_GC_CARD_BVEC_SIZE_IN_LONGS \ |
86 | ((SCM_GC_CARD_N_CELLS + SCM_C_BVEC_LONG_BITS - 1) / SCM_C_BVEC_LONG_BITS) | |
87 | #define SCM_GC_IN_CARD_HEADERP(x) \ | |
88 | (scm_t_cell *) (x) < SCM_GC_CELL_CARD (x) + SCM_GC_CARD_N_HEADER_CELLS | |
c7743d02 HWN |
89 | |
90 | ||
91 | int scm_getenv_int (const char *var, int def); | |
92 | ||
93 | ||
94 | typedef enum { return_on_error, abort_on_error } policy_on_error; | |
95 | ||
96 | /* gc-freelist*/ | |
97 | ||
98 | /* | |
99 | FREELIST: | |
100 | ||
101 | A struct holding GC statistics on a particular type of cells. | |
102 | */ | |
103 | typedef struct scm_t_cell_type_statistics { | |
104 | ||
105 | /* | |
106 | heap segment where the last cell was allocated | |
107 | */ | |
108 | int heap_segment_idx; | |
109 | ||
110 | /* minimum yield on this list in order not to grow the heap | |
111 | */ | |
112 | long min_yield; | |
113 | ||
114 | /* defines min_yield as percent of total heap size | |
115 | */ | |
116 | int min_yield_fraction; | |
117 | ||
118 | /* number of cells per object on this list */ | |
119 | int span; | |
120 | ||
121 | /* number of collected cells during last GC */ | |
122 | unsigned long collected; | |
123 | ||
124 | /* number of collected cells during penultimate GC */ | |
125 | unsigned long collected_1; | |
126 | ||
127 | /* total number of cells in heap segments | |
128 | * belonging to this list. | |
129 | */ | |
130 | unsigned long heap_size; | |
131 | ||
c2cbcc57 | 132 | |
c7743d02 HWN |
133 | } scm_t_cell_type_statistics; |
134 | ||
135 | ||
4c7016dc HWN |
136 | /* Sweep statistics. */ |
137 | typedef struct scm_sweep_statistics | |
138 | { | |
139 | /* Number of cells "swept", i.e., visited during the sweep operation. */ | |
140 | unsigned swept; | |
141 | ||
142 | /* Number of cells collected during the sweep operation. This number must | |
143 | alsways be lower than or equal to SWEPT. */ | |
144 | unsigned collected; | |
145 | } scm_t_sweep_statistics; | |
146 | ||
147 | #define scm_i_sweep_statistics_init(_stats) \ | |
148 | do \ | |
149 | { \ | |
150 | (_stats)->swept = (_stats)->collected = 0; \ | |
151 | } \ | |
152 | while (0) | |
153 | ||
154 | #define scm_i_sweep_statistics_sum(_sum, _addition) \ | |
155 | do \ | |
156 | { \ | |
157 | (_sum)->swept += (_addition).swept; \ | |
158 | (_sum)->collected += (_addition).collected; \ | |
159 | } \ | |
160 | while (0) | |
161 | ||
4c7016dc | 162 | \f |
c7743d02 HWN |
163 | extern scm_t_cell_type_statistics scm_i_master_freelist; |
164 | extern scm_t_cell_type_statistics scm_i_master_freelist2; | |
c7743d02 | 165 | |
102dbb6f | 166 | SCM_INTERNAL |
4c7016dc | 167 | void scm_i_adjust_min_yield (scm_t_cell_type_statistics *freelist, |
d9f71a07 LC |
168 | scm_t_sweep_statistics sweep_stats, |
169 | scm_t_sweep_statistics sweep_stats_1); | |
102dbb6f | 170 | SCM_INTERNAL |
c7743d02 | 171 | void scm_i_gc_sweep_freelist_reset (scm_t_cell_type_statistics *freelist); |
102dbb6f | 172 | SCM_INTERNAL |
c7743d02 | 173 | int scm_i_gc_grow_heap_p (scm_t_cell_type_statistics * freelist); |
dac04e9f HWN |
174 | |
175 | ||
c7743d02 HWN |
176 | #define SCM_HEAP_SIZE \ |
177 | (scm_i_master_freelist.heap_size + scm_i_master_freelist2.heap_size) | |
178 | ||
179 | ||
180 | #define SCM_MAX(A, B) ((A) > (B) ? (A) : (B)) | |
181 | #define SCM_MIN(A, B) ((A) < (B) ? (A) : (B)) | |
182 | ||
d3774e2c MV |
183 | /* CELL_P checks a random word whether it has the right form for a |
184 | pointer to a cell. Use scm_i_find_heap_segment_containing_object | |
185 | to find out whether it actually points to a real cell. | |
186 | ||
187 | The right form for a cell pointer is this: the low three bits must | |
188 | be scm_tc3_cons, and when the scm_tc3_cons tag is stripped, the | |
189 | resulting pointer must be correctly aligned. | |
190 | scm_i_initialize_heap_segment_data guarantees that the test below | |
191 | works. | |
192 | */ | |
193 | #define CELL_P(x) ((SCM_UNPACK(x) & (sizeof(scm_t_cell)-1)) == scm_tc3_cons) | |
c7743d02 HWN |
194 | |
195 | /* | |
196 | gc-mark | |
197 | */ | |
198 | ||
199 | ||
200 | void scm_mark_all (void); | |
201 | ||
202 | ||
203 | ||
204 | /* | |
205 | gc-segment: | |
206 | */ | |
207 | ||
208 | ||
209 | ||
210 | ||
211 | /* | |
212 | ||
213 | Cells are stored in a heap-segment: it is a contiguous chunk of | |
214 | memory, that associated with one freelist. | |
215 | */ | |
216 | ||
217 | typedef struct scm_t_heap_segment | |
218 | { | |
219 | /* | |
220 | {lower, upper} bounds of the segment | |
221 | ||
222 | The upper bound is also the start of the mark space. | |
223 | */ | |
224 | scm_t_cell *bounds[2]; | |
225 | ||
226 | /* | |
227 | If we ever decide to give it back, we could do it with this ptr. | |
228 | ||
229 | Note that giving back memory is not very useful; as long we don't | |
230 | touch a chunk of memory, the virtual memory system will keep it | |
231 | swapped out. We could simply forget about a block. | |
232 | ||
233 | (not that we do that, but anyway.) | |
234 | */ | |
235 | ||
236 | void* malloced; | |
237 | ||
238 | scm_t_cell * next_free_card; | |
239 | ||
240 | /* address of the head-of-freelist pointer for this segment's cells. | |
241 | All segments usually point to the same one, scm_i_freelist. */ | |
242 | scm_t_cell_type_statistics *freelist; | |
243 | ||
244 | /* number of cells per object in this segment */ | |
245 | int span; | |
246 | ||
247 | ||
248 | /* | |
249 | Is this the first time that the cells are accessed? | |
250 | */ | |
251 | int first_time; | |
252 | ||
253 | } scm_t_heap_segment; | |
254 | ||
255 | ||
256 | ||
257 | /* | |
258 | ||
259 | A table of segment records is kept that records the upper and | |
260 | lower extents of the segment; this is used during the conservative | |
261 | phase of gc to identify probably gc roots (because they point | |
262 | into valid segments at reasonable offsets). | |
263 | ||
264 | */ | |
265 | extern scm_t_heap_segment ** scm_i_heap_segment_table; | |
266 | extern size_t scm_i_heap_segment_table_size; | |
267 | ||
268 | ||
102dbb6f LC |
269 | SCM_INTERNAL int scm_i_init_card_freelist (scm_t_cell * card, SCM *free_list, |
270 | scm_t_heap_segment*); | |
271 | SCM_INTERNAL int scm_i_sweep_card (scm_t_cell *card, SCM *free_list, | |
272 | scm_t_heap_segment *); | |
273 | SCM_INTERNAL void scm_i_card_statistics (scm_t_cell *p, SCM hashtab, | |
274 | scm_t_heap_segment *seg); | |
275 | SCM_INTERNAL char const *scm_i_tag_name (scm_t_bits tag); /* MOVEME */ | |
276 | ||
277 | SCM_INTERNAL int scm_i_initialize_heap_segment_data (scm_t_heap_segment *seg, | |
278 | size_t requested); | |
279 | SCM_INTERNAL int scm_i_segment_card_count (scm_t_heap_segment *seg); | |
280 | SCM_INTERNAL int scm_i_segment_cell_count (scm_t_heap_segment *seg); | |
281 | ||
282 | SCM_INTERNAL void scm_i_clear_segment_mark_space (scm_t_heap_segment *seg); | |
283 | SCM_INTERNAL scm_t_heap_segment * | |
284 | scm_i_make_empty_heap_segment (scm_t_cell_type_statistics*); | |
285 | SCM_INTERNAL SCM scm_i_sweep_some_cards (scm_t_heap_segment *seg, | |
286 | scm_t_sweep_statistics *sweep_stats); | |
287 | SCM_INTERNAL void scm_i_sweep_segment (scm_t_heap_segment *seg, | |
288 | scm_t_sweep_statistics *sweep_stats); | |
289 | ||
290 | SCM_INTERNAL void scm_i_heap_segment_statistics (scm_t_heap_segment *seg, | |
291 | SCM tab); | |
292 | ||
293 | ||
294 | SCM_INTERNAL int scm_i_insert_segment (scm_t_heap_segment *seg); | |
295 | SCM_INTERNAL long int scm_i_find_heap_segment_containing_object (SCM obj); | |
296 | SCM_INTERNAL int scm_i_get_new_heap_segment (scm_t_cell_type_statistics *, | |
297 | scm_t_sweep_statistics, | |
298 | policy_on_error); | |
299 | SCM_INTERNAL void scm_i_clear_mark_space (void); | |
300 | SCM_INTERNAL void scm_i_sweep_segments (void); | |
301 | SCM_INTERNAL SCM scm_i_sweep_some_segments (scm_t_cell_type_statistics *fl, | |
302 | scm_t_sweep_statistics *sweep_stats); | |
303 | SCM_INTERNAL void scm_i_reset_segments (void); | |
304 | SCM_INTERNAL void scm_i_sweep_all_segments (char const *reason, | |
305 | scm_t_sweep_statistics *sweep_stats); | |
306 | SCM_INTERNAL SCM scm_i_all_segments_statistics (SCM hashtab); | |
307 | SCM_INTERNAL void scm_i_make_initial_segment (int init_heap_size, | |
308 | scm_t_cell_type_statistics *fl); | |
c7743d02 HWN |
309 | |
310 | extern long int scm_i_deprecated_memory_return; | |
311 | ||
312 | ||
313 | /* | |
314 | global init funcs. | |
315 | */ | |
316 | void scm_gc_init_malloc (void); | |
317 | void scm_gc_init_freelist (void); | |
318 | void scm_gc_init_segments (void); | |
319 | void scm_gc_init_mark (void); | |
eab1b259 HWN |
320 | |
321 | ||
c7743d02 | 322 | #endif |