Mercurial > hg > xemacs-beta
annotate src/gccache-x.c @ 5159:cb303ff63e76
merge
| author | Ben Wing <ben@xemacs.org> |
|---|---|
| date | Fri, 19 Mar 2010 17:02:11 -0500 |
| parents | 6f2158fa75ed |
| children | 308d34e9f07d |
| rev | line source |
|---|---|
| 2587 | 1 /* Efficient caching of X GCs (graphics contexts). |
| 2 Copyright (C) 1993 Free Software Foundation, Inc. | |
| 3 Copyright (C) 1994, 1995 Board of Trustees, University of Illinois. | |
|
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4 Copyright (C) 2010 Ben Wing. |
| 2587 | 5 |
| 6 This file is part of XEmacs. | |
| 7 | |
| 8 XEmacs is free software; you can redistribute it and/or modify it | |
| 9 under the terms of the GNU General Public License as published by the | |
| 10 Free Software Foundation; either version 2, or (at your option) any | |
| 11 later version. | |
| 12 | |
| 13 XEmacs is distributed in the hope that it will be useful, but WITHOUT | |
| 14 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 16 for more details. | |
| 17 | |
| 18 You should have received a copy of the GNU General Public License | |
| 19 along with XEmacs; see the file COPYING. If not, write to | |
| 20 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
| 21 Boston, MA 02111-1307, USA. */ | |
| 22 | |
| 23 /* Synched up with: Not in FSF. */ | |
| 24 | |
| 25 /* Emacs uses a lot of different display attributes; for example, assume | |
| 26 that only four fonts are in use (normal, bold, italic, and bold-italic). | |
| 27 Then assume that one stipple or background is used for text selections, | |
| 28 and another is used for highlighting mousable regions. That makes 16 | |
| 29 GCs already. Add in the fact that another GC may be needed to display | |
| 30 the text cursor in any of those regions, and you've got 32. Add in | |
| 31 more fonts, and it keeps increasing exponentially. | |
| 32 | |
| 33 We used to keep these GCs in a cache of merged (fully qualified) faces. | |
| 34 However, a lot of other code in xterm.c used XChangeGC of existing GCs, | |
| 35 which is kind of slow and kind of random. Also, managing the face cache | |
| 36 was tricky because it was hard to know when a face was no longer visible | |
| 37 on the frame -- we had to mark all frames as garbaged whenever a face | |
| 38 was changed, which caused an unpleasant amount of flicker (since faces are | |
| 39 created/destroyed (= changed) whenever a frame is created/destroyed. | |
| 40 | |
| 41 So this code maintains a cache at the GC level instead of at the face | |
| 42 level. There is an upper limit on the size of the cache, after which we | |
| 43 will stop creating GCs and start reusing them (reusing the least-recently- | |
| 44 used ones first). So if faces get changed, their GCs will eventually be | |
| 45 recycled. Also more sharing of GCs is possible. | |
| 46 | |
| 47 This code uses hash tables. It could be that, if the cache size is small | |
| 48 enough, a linear search might be faster; but I doubt it, since we need | |
| 49 `equal' comparisons, not `eq', and I expect that the optimal cache size | |
| 50 will be ~100. | |
| 51 | |
| 52 Written by jwz, 14 jun 93 | |
| 53 */ | |
| 54 | |
| 55 #include <config.h> | |
|
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56 #include "lisp.h" |
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57 #include "hash.h" |
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58 |
| 4917 | 59 #include "gccache-x.h" |
| 2587 | 60 |
| 61 #define GC_CACHE_SIZE 100 | |
| 62 | |
| 63 #define GCCACHE_HASH | |
| 64 | |
| 65 struct gcv_and_mask { | |
| 66 XGCValues gcv; | |
| 67 unsigned long mask; | |
| 68 }; | |
| 69 | |
| 70 struct gc_cache_cell { | |
| 71 GC gc; | |
| 72 struct gcv_and_mask gcvm; | |
| 73 struct gc_cache_cell *prev, *next; | |
| 74 }; | |
| 75 | |
| 76 struct gc_cache { | |
| 77 Display *dpy; /* used only as arg to XCreateGC/XFreeGC */ | |
| 78 Window window; /* used only as arg to XCreateGC */ | |
| 79 int size; | |
| 80 struct gc_cache_cell *head; | |
| 81 struct gc_cache_cell *tail; | |
| 82 #ifdef GCCACHE_HASH | |
| 83 struct hash_table *table; | |
| 84 #endif | |
| 85 | |
| 86 int create_count; | |
| 87 int delete_count; | |
| 88 }; | |
| 89 | |
| 90 #ifdef GCCACHE_HASH | |
| 91 static Hashcode | |
| 92 gc_cache_hash (const void *arg) | |
| 93 { | |
| 94 const struct gcv_and_mask *gcvm = (const struct gcv_and_mask *) arg; | |
| 95 unsigned long *longs = (unsigned long *) &gcvm->gcv; | |
| 96 Hashcode hash = gcvm->mask; | |
| 97 int i; | |
| 98 /* This could look at the mask and only use the used slots in the | |
| 99 hash code. That would win in that we wouldn't have to initialize | |
| 100 every slot of the gcv when calling gc_cache_lookup. But we need | |
| 101 the hash function to be as fast as possible; some timings should | |
| 102 be done. */ | |
| 103 for (i = 0; i < (int) (sizeof (XGCValues) / sizeof (unsigned long)); i++) | |
| 104 hash = (hash << 1) ^ *longs++; | |
| 105 return hash; | |
| 106 } | |
| 107 | |
| 108 #endif /* GCCACHE_HASH */ | |
| 109 | |
| 110 static int | |
| 111 gc_cache_eql (const void *arg1, const void *arg2) | |
| 112 { | |
| 113 /* See comment in gc_cache_hash */ | |
| 114 return !memcmp (arg1, arg2, sizeof (struct gcv_and_mask)); | |
| 115 } | |
| 116 | |
| 117 struct gc_cache * | |
| 118 make_gc_cache (Display *dpy, Window window) | |
| 119 { | |
| 120 struct gc_cache *cache = xnew (struct gc_cache); | |
| 121 cache->dpy = dpy; | |
| 122 cache->window = window; | |
| 123 cache->size = 0; | |
| 124 cache->head = cache->tail = 0; | |
| 125 cache->create_count = cache->delete_count = 0; | |
| 126 #ifdef GCCACHE_HASH | |
| 127 cache->table = | |
| 128 make_general_hash_table (GC_CACHE_SIZE, gc_cache_hash, gc_cache_eql); | |
| 129 #endif | |
| 130 return cache; | |
| 131 } | |
| 132 | |
| 133 void | |
| 134 free_gc_cache (struct gc_cache *cache) | |
| 135 { | |
| 136 struct gc_cache_cell *rest, *next; | |
| 137 rest = cache->head; | |
| 138 while (rest) | |
| 139 { | |
| 140 XFreeGC (cache->dpy, rest->gc); | |
| 141 next = rest->next; | |
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142 xfree (rest); |
| 2587 | 143 rest = next; |
| 144 } | |
| 145 #ifdef GCCACHE_HASH | |
| 146 free_hash_table (cache->table); | |
| 147 #endif | |
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148 xfree (cache); |
| 2587 | 149 } |
| 150 | |
| 151 GC | |
| 152 gc_cache_lookup (struct gc_cache *cache, XGCValues *gcv, unsigned long mask) | |
| 153 { | |
| 154 struct gc_cache_cell *cell, *next, *prev; | |
| 155 struct gcv_and_mask gcvm; | |
| 156 | |
| 3094 | 157 #ifdef DEBUG_XEMACS |
| 158 (void) describe_gc_cache (cache, DGCCFLAG_DISABLE); | |
| 159 #endif | |
| 160 | |
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parents:
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diff
changeset
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161 assert ((!!cache->head) == (!!cache->tail)); |
|
6f2158fa75ed
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Ben Wing <ben@xemacs.org>
parents:
4976
diff
changeset
|
162 assert (!(cache->head && (cache->head->prev || cache->tail->next))); |
| 2587 | 163 |
| 164 gcvm.mask = mask; | |
| 165 gcvm.gcv = *gcv; /* this copies... */ | |
| 166 | |
| 167 #ifdef GCCACHE_HASH | |
| 168 | |
| 169 /* The intermediate cast fools gcc into not outputting strict-aliasing | |
| 170 complaints */ | |
| 171 if (gethash (&gcvm, cache->table, (const void **) (void *) &cell)) | |
| 172 | |
| 173 #else /* !GCCACHE_HASH */ | |
| 174 | |
| 175 cell = cache->tail; /* start at the end (most recently used) */ | |
| 176 while (cell) | |
| 177 { | |
| 178 if (gc_cache_eql (&gcvm, &cell->gcvm)) | |
| 179 break; | |
| 180 else | |
| 181 cell = cell->prev; | |
| 182 } | |
| 183 | |
| 184 /* #### This whole file needs some serious overhauling. */ | |
| 185 if (!(mask | GCTile) && cell->gc->values.tile) | |
| 186 cell = 0; | |
| 187 else if (!(mask | GCStipple) && cell->gc->values.stipple) | |
| 188 cell = 0; | |
| 189 | |
| 190 if (cell) | |
| 191 | |
| 192 #endif /* !GCCACHE_HASH */ | |
| 193 | |
| 194 { | |
| 195 /* Found a cell. Move this cell to the end of the list, so that it | |
| 196 will be less likely to be collected than a cell that was accessed | |
| 197 less recently. | |
| 198 */ | |
| 3094 | 199 #if 0 |
| 200 debug_out ("Returning cached GC: %08lx\n", XE_GCONTEXT(cell)); | |
| 201 #endif | |
| 2587 | 202 if (cell == cache->tail) |
| 203 return cell->gc; | |
| 204 | |
| 205 next = cell->next; | |
| 206 prev = cell->prev; | |
| 207 if (prev) prev->next = next; | |
| 208 if (next) next->prev = prev; | |
| 209 if (cache->head == cell) cache->head = next; | |
| 210 cell->next = 0; | |
| 211 cell->prev = cache->tail; | |
| 212 cache->tail->next = cell; | |
| 213 cache->tail = cell; | |
|
5050
6f2158fa75ed
Fix quick-build, use asserts() in place of ABORT()
Ben Wing <ben@xemacs.org>
parents:
4976
diff
changeset
|
214 assert (cache->head != cell); |
|
6f2158fa75ed
Fix quick-build, use asserts() in place of ABORT()
Ben Wing <ben@xemacs.org>
parents:
4976
diff
changeset
|
215 assert (!cell->next); |
|
6f2158fa75ed
Fix quick-build, use asserts() in place of ABORT()
Ben Wing <ben@xemacs.org>
parents:
4976
diff
changeset
|
216 assert (!cache->head->prev); |
|
6f2158fa75ed
Fix quick-build, use asserts() in place of ABORT()
Ben Wing <ben@xemacs.org>
parents:
4976
diff
changeset
|
217 assert (!cache->tail->next); |
| 2587 | 218 return cell->gc; |
| 219 } | |
| 220 | |
| 221 /* else, cache miss. */ | |
| 222 | |
| 223 if (cache->size == GC_CACHE_SIZE) | |
| 224 /* Reuse the first cell on the list (least-recently-used). | |
| 225 Remove it from the list, and unhash it from the table. | |
| 226 */ | |
| 227 { | |
| 228 cell = cache->head; | |
| 229 cache->head = cell->next; | |
| 230 cache->head->prev = 0; | |
| 231 if (cache->tail == cell) cache->tail = 0; /* only one */ | |
| 3243 | 232 #if 0 |
| 3094 | 233 debug_out ("Cache full, freeing GC: %08lx\n ", XE_GCONTEXT(cell)); |
| 3243 | 234 #endif |
| 2587 | 235 XFreeGC (cache->dpy, cell->gc); |
| 236 cache->delete_count++; | |
| 237 #ifdef GCCACHE_HASH | |
| 238 remhash (&cell->gcvm, cache->table); | |
| 239 #endif | |
| 240 } | |
| 241 else if (cache->size > GC_CACHE_SIZE) | |
| 242 ABORT (); | |
| 243 else | |
| 244 { | |
| 245 /* Allocate a new cell (don't put it in the list or table yet). */ | |
| 246 cell = xnew (struct gc_cache_cell); | |
| 247 cache->size++; | |
| 248 } | |
| 249 | |
| 250 /* Now we've got a cell (new or reused). Fill it in. */ | |
| 251 memcpy (&cell->gcvm.gcv, gcv, sizeof (XGCValues)); | |
| 252 cell->gcvm.mask = mask; | |
| 253 | |
| 254 /* Put the cell on the end of the list. */ | |
| 255 cell->next = 0; | |
| 256 cell->prev = cache->tail; | |
| 257 if (cache->tail) cache->tail->next = cell; | |
| 258 cache->tail = cell; | |
| 259 if (! cache->head) cache->head = cell; | |
| 260 | |
| 261 cache->create_count++; | |
| 262 #ifdef GCCACHE_HASH | |
| 263 /* Hash it in the table */ | |
| 264 puthash (&cell->gcvm, cell, cache->table); | |
| 265 #endif | |
| 266 | |
| 267 /* Now make and return the GC. */ | |
| 268 cell->gc = XCreateGC (cache->dpy, cache->window, mask, gcv); | |
| 269 | |
| 270 /* debug */ | |
| 271 assert (cell->gc == gc_cache_lookup (cache, gcv, mask)); | |
| 272 | |
| 3094 | 273 #if 0 |
| 274 debug_out ("Returning new GC: %08lx\n ", XE_GCONTEXT(cell)); | |
| 275 #endif | |
| 2587 | 276 return cell->gc; |
| 277 } | |
| 278 | |
| 279 | |
| 280 #ifdef DEBUG_XEMACS | |
| 281 | |
| 3094 | 282 /* FLAGS |
| 283 The flags argument is a bitwise or of any of the following: | |
| 284 | |
| 285 DGCCFLAG_SUMMARY Summary statistics for cache | |
| 286 DGCCFLAG_LIST_CELLS If summary is being printed, print cell IDs too. | |
| 287 DGCCFLAG_CELL_DETAILS If cell IDs are being printed, additionally | |
| 288 print the internal fields used and values. | |
| 289 | |
| 290 DGCCFLAG_DEFAULT A predefined combination giving whatever the | |
| 291 maintainers are currently interested in seeing. | |
| 292 */ | |
| 2587 | 293 void |
| 3094 | 294 describe_gc_cache (struct gc_cache *cache, int flags) |
| 2587 | 295 { |
| 296 int count = 0; | |
| 297 struct gc_cache_cell *cell = cache->head; | |
| 3094 | 298 |
| 299 if (! flags & DGCCFLAG_SUMMARY) return; | |
| 300 | |
| 2587 | 301 stderr_out ("\nsize: %d", cache->size); |
| 302 stderr_out ("\ncreated: %d", cache->create_count); | |
| 303 stderr_out ("\ndeleted: %d", cache->delete_count); | |
| 304 | |
| 3094 | 305 if (flags & DGCCFLAG_LIST_CELLS) |
| 306 while (cell) | |
| 307 { | |
| 308 struct gc_cache_cell *cell2; | |
| 309 int i = 0; | |
| 310 stderr_out ("\n%d:\t0x%lx GC: 0x%08lx hash: 0x%08lx\n", | |
| 311 count, (long) cell, (long) XE_GCONTEXT(cell), | |
| 312 gc_cache_hash (&cell->gcvm)); | |
| 313 | |
| 314 for (cell2 = cache->head; cell2; cell2 = cell2->next, i++) | |
| 315 if (count != i && | |
| 316 gc_cache_hash (&cell->gcvm) == gc_cache_hash (&cell2->gcvm)) | |
| 317 stderr_out ("\tHASH COLLISION with cell %d\n", i); | |
| 318 stderr_out ("\tmask: %8lx\n", cell->gcvm.mask); | |
| 319 | |
| 320 if (flags & DGCCFLAG_CELL_DETAILS) | |
| 321 { | |
| 2587 | 322 #define FROB(field) do { \ |
| 323 if ((int)cell->gcvm.gcv.field != (~0)) \ | |
| 324 stderr_out ("\t%-12s%8x\n", #field ":", (int)cell->gcvm.gcv.field); \ | |
| 325 } while (0) | |
| 3094 | 326 FROB (function); |
| 327 FROB (plane_mask); | |
| 328 FROB (foreground); | |
| 329 FROB (background); | |
| 330 FROB (line_width); | |
| 331 FROB (line_style); | |
| 332 FROB (cap_style); | |
| 333 FROB (join_style); | |
| 334 FROB (fill_style); | |
| 335 FROB (fill_rule); | |
| 336 FROB (arc_mode); | |
| 337 FROB (tile); | |
| 338 FROB (stipple); | |
| 339 FROB (ts_x_origin); | |
| 340 FROB (ts_y_origin); | |
| 341 FROB (font); | |
| 342 FROB (subwindow_mode); | |
| 343 FROB (graphics_exposures); | |
| 344 FROB (clip_x_origin); | |
| 345 FROB (clip_y_origin); | |
| 346 FROB (clip_mask); | |
| 347 FROB (dash_offset); | |
| 2587 | 348 #undef FROB |
| 3094 | 349 } |
| 2587 | 350 |
| 3094 | 351 count++; |
| 352 if (cell->next && cell == cache->tail) | |
| 353 stderr_out ("\nERROR! tail is here!\n\n"); | |
| 354 else if (!cell->next && cell != cache->tail) | |
| 355 stderr_out ("\nERROR! tail is not at the end\n\n"); | |
| 356 cell = cell->next; | |
| 357 } /* while (cell) */ | |
| 358 | |
| 2587 | 359 if (count != cache->size) |
| 360 stderr_out ("\nERROR! count should be %d\n\n", cache->size); | |
| 361 } | |
| 362 | |
| 363 #endif /* DEBUG_XEMACS */ |