Mercurial > hg > xemacs-beta
annotate src/gccache-x.c @ 5008:cad59a0a3b19
Add license information from Marcus Thiessel.
See xemacs-beta message <20100208091453.25900@gmx.net>.
| author | Jerry James <james@xemacs.org> |
|---|---|
| date | Tue, 09 Feb 2010 09:50:49 -0700 |
| parents | 16112448d484 |
| children | 6f2158fa75ed |
| 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. | |
| 4 | |
| 5 This file is part of XEmacs. | |
| 6 | |
| 7 XEmacs is free software; you can redistribute it and/or modify it | |
| 8 under the terms of the GNU General Public License as published by the | |
| 9 Free Software Foundation; either version 2, or (at your option) any | |
| 10 later version. | |
| 11 | |
| 12 XEmacs is distributed in the hope that it will be useful, but WITHOUT | |
| 13 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| 15 for more details. | |
| 16 | |
| 17 You should have received a copy of the GNU General Public License | |
| 18 along with XEmacs; see the file COPYING. If not, write to | |
| 19 the Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
| 20 Boston, MA 02111-1307, USA. */ | |
| 21 | |
| 22 /* Synched up with: Not in FSF. */ | |
| 23 | |
| 24 /* Emacs uses a lot of different display attributes; for example, assume | |
| 25 that only four fonts are in use (normal, bold, italic, and bold-italic). | |
| 26 Then assume that one stipple or background is used for text selections, | |
| 27 and another is used for highlighting mousable regions. That makes 16 | |
| 28 GCs already. Add in the fact that another GC may be needed to display | |
| 29 the text cursor in any of those regions, and you've got 32. Add in | |
| 30 more fonts, and it keeps increasing exponentially. | |
| 31 | |
| 32 We used to keep these GCs in a cache of merged (fully qualified) faces. | |
| 33 However, a lot of other code in xterm.c used XChangeGC of existing GCs, | |
| 34 which is kind of slow and kind of random. Also, managing the face cache | |
| 35 was tricky because it was hard to know when a face was no longer visible | |
| 36 on the frame -- we had to mark all frames as garbaged whenever a face | |
| 37 was changed, which caused an unpleasant amount of flicker (since faces are | |
| 38 created/destroyed (= changed) whenever a frame is created/destroyed. | |
| 39 | |
| 40 So this code maintains a cache at the GC level instead of at the face | |
| 41 level. There is an upper limit on the size of the cache, after which we | |
| 42 will stop creating GCs and start reusing them (reusing the least-recently- | |
| 43 used ones first). So if faces get changed, their GCs will eventually be | |
| 44 recycled. Also more sharing of GCs is possible. | |
| 45 | |
| 46 This code uses hash tables. It could be that, if the cache size is small | |
| 47 enough, a linear search might be faster; but I doubt it, since we need | |
| 48 `equal' comparisons, not `eq', and I expect that the optimal cache size | |
| 49 will be ~100. | |
| 50 | |
| 51 Written by jwz, 14 jun 93 | |
| 52 */ | |
| 53 | |
| 54 #include <config.h> | |
|
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55 #include "lisp.h" |
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56 #include "hash.h" |
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changeset
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57 |
| 4917 | 58 #include "gccache-x.h" |
| 2587 | 59 |
| 60 #define GC_CACHE_SIZE 100 | |
| 61 | |
| 62 #define GCCACHE_HASH | |
| 63 | |
| 64 struct gcv_and_mask { | |
| 65 XGCValues gcv; | |
| 66 unsigned long mask; | |
| 67 }; | |
| 68 | |
| 69 struct gc_cache_cell { | |
| 70 GC gc; | |
| 71 struct gcv_and_mask gcvm; | |
| 72 struct gc_cache_cell *prev, *next; | |
| 73 }; | |
| 74 | |
| 75 struct gc_cache { | |
| 76 Display *dpy; /* used only as arg to XCreateGC/XFreeGC */ | |
| 77 Window window; /* used only as arg to XCreateGC */ | |
| 78 int size; | |
| 79 struct gc_cache_cell *head; | |
| 80 struct gc_cache_cell *tail; | |
| 81 #ifdef GCCACHE_HASH | |
| 82 struct hash_table *table; | |
| 83 #endif | |
| 84 | |
| 85 int create_count; | |
| 86 int delete_count; | |
| 87 }; | |
| 88 | |
| 89 #ifdef GCCACHE_HASH | |
| 90 static Hashcode | |
| 91 gc_cache_hash (const void *arg) | |
| 92 { | |
| 93 const struct gcv_and_mask *gcvm = (const struct gcv_and_mask *) arg; | |
| 94 unsigned long *longs = (unsigned long *) &gcvm->gcv; | |
| 95 Hashcode hash = gcvm->mask; | |
| 96 int i; | |
| 97 /* This could look at the mask and only use the used slots in the | |
| 98 hash code. That would win in that we wouldn't have to initialize | |
| 99 every slot of the gcv when calling gc_cache_lookup. But we need | |
| 100 the hash function to be as fast as possible; some timings should | |
| 101 be done. */ | |
| 102 for (i = 0; i < (int) (sizeof (XGCValues) / sizeof (unsigned long)); i++) | |
| 103 hash = (hash << 1) ^ *longs++; | |
| 104 return hash; | |
| 105 } | |
| 106 | |
| 107 #endif /* GCCACHE_HASH */ | |
| 108 | |
| 109 static int | |
| 110 gc_cache_eql (const void *arg1, const void *arg2) | |
| 111 { | |
| 112 /* See comment in gc_cache_hash */ | |
| 113 return !memcmp (arg1, arg2, sizeof (struct gcv_and_mask)); | |
| 114 } | |
| 115 | |
| 116 struct gc_cache * | |
| 117 make_gc_cache (Display *dpy, Window window) | |
| 118 { | |
| 119 struct gc_cache *cache = xnew (struct gc_cache); | |
| 120 cache->dpy = dpy; | |
| 121 cache->window = window; | |
| 122 cache->size = 0; | |
| 123 cache->head = cache->tail = 0; | |
| 124 cache->create_count = cache->delete_count = 0; | |
| 125 #ifdef GCCACHE_HASH | |
| 126 cache->table = | |
| 127 make_general_hash_table (GC_CACHE_SIZE, gc_cache_hash, gc_cache_eql); | |
| 128 #endif | |
| 129 return cache; | |
| 130 } | |
| 131 | |
| 132 void | |
| 133 free_gc_cache (struct gc_cache *cache) | |
| 134 { | |
| 135 struct gc_cache_cell *rest, *next; | |
| 136 rest = cache->head; | |
| 137 while (rest) | |
| 138 { | |
| 139 XFreeGC (cache->dpy, rest->gc); | |
| 140 next = rest->next; | |
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141 xfree (rest); |
| 2587 | 142 rest = next; |
| 143 } | |
| 144 #ifdef GCCACHE_HASH | |
| 145 free_hash_table (cache->table); | |
| 146 #endif | |
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147 xfree (cache); |
| 2587 | 148 } |
| 149 | |
| 150 GC | |
| 151 gc_cache_lookup (struct gc_cache *cache, XGCValues *gcv, unsigned long mask) | |
| 152 { | |
| 153 struct gc_cache_cell *cell, *next, *prev; | |
| 154 struct gcv_and_mask gcvm; | |
| 155 | |
| 3094 | 156 #ifdef DEBUG_XEMACS |
| 157 (void) describe_gc_cache (cache, DGCCFLAG_DISABLE); | |
| 158 #endif | |
| 159 | |
| 2587 | 160 if ((!!cache->head) != (!!cache->tail)) ABORT (); |
| 161 if (cache->head && (cache->head->prev || cache->tail->next)) ABORT (); | |
| 162 | |
| 163 gcvm.mask = mask; | |
| 164 gcvm.gcv = *gcv; /* this copies... */ | |
| 165 | |
| 166 #ifdef GCCACHE_HASH | |
| 167 | |
| 168 /* The intermediate cast fools gcc into not outputting strict-aliasing | |
| 169 complaints */ | |
| 170 if (gethash (&gcvm, cache->table, (const void **) (void *) &cell)) | |
| 171 | |
| 172 #else /* !GCCACHE_HASH */ | |
| 173 | |
| 174 cell = cache->tail; /* start at the end (most recently used) */ | |
| 175 while (cell) | |
| 176 { | |
| 177 if (gc_cache_eql (&gcvm, &cell->gcvm)) | |
| 178 break; | |
| 179 else | |
| 180 cell = cell->prev; | |
| 181 } | |
| 182 | |
| 183 /* #### This whole file needs some serious overhauling. */ | |
| 184 if (!(mask | GCTile) && cell->gc->values.tile) | |
| 185 cell = 0; | |
| 186 else if (!(mask | GCStipple) && cell->gc->values.stipple) | |
| 187 cell = 0; | |
| 188 | |
| 189 if (cell) | |
| 190 | |
| 191 #endif /* !GCCACHE_HASH */ | |
| 192 | |
| 193 { | |
| 194 /* Found a cell. Move this cell to the end of the list, so that it | |
| 195 will be less likely to be collected than a cell that was accessed | |
| 196 less recently. | |
| 197 */ | |
| 3094 | 198 #if 0 |
| 199 debug_out ("Returning cached GC: %08lx\n", XE_GCONTEXT(cell)); | |
| 200 #endif | |
| 2587 | 201 if (cell == cache->tail) |
| 202 return cell->gc; | |
| 203 | |
| 204 next = cell->next; | |
| 205 prev = cell->prev; | |
| 206 if (prev) prev->next = next; | |
| 207 if (next) next->prev = prev; | |
| 208 if (cache->head == cell) cache->head = next; | |
| 209 cell->next = 0; | |
| 210 cell->prev = cache->tail; | |
| 211 cache->tail->next = cell; | |
| 212 cache->tail = cell; | |
| 213 if (cache->head == cell) ABORT (); | |
| 214 if (cell->next) ABORT (); | |
| 215 if (cache->head->prev) ABORT (); | |
| 216 if (cache->tail->next) ABORT (); | |
| 217 return cell->gc; | |
| 218 } | |
| 219 | |
| 220 /* else, cache miss. */ | |
| 221 | |
| 222 if (cache->size == GC_CACHE_SIZE) | |
| 223 /* Reuse the first cell on the list (least-recently-used). | |
| 224 Remove it from the list, and unhash it from the table. | |
| 225 */ | |
| 226 { | |
| 227 cell = cache->head; | |
| 228 cache->head = cell->next; | |
| 229 cache->head->prev = 0; | |
| 230 if (cache->tail == cell) cache->tail = 0; /* only one */ | |
| 3243 | 231 #if 0 |
| 3094 | 232 debug_out ("Cache full, freeing GC: %08lx\n ", XE_GCONTEXT(cell)); |
| 3243 | 233 #endif |
| 2587 | 234 XFreeGC (cache->dpy, cell->gc); |
| 235 cache->delete_count++; | |
| 236 #ifdef GCCACHE_HASH | |
| 237 remhash (&cell->gcvm, cache->table); | |
| 238 #endif | |
| 239 } | |
| 240 else if (cache->size > GC_CACHE_SIZE) | |
| 241 ABORT (); | |
| 242 else | |
| 243 { | |
| 244 /* Allocate a new cell (don't put it in the list or table yet). */ | |
| 245 cell = xnew (struct gc_cache_cell); | |
| 246 cache->size++; | |
| 247 } | |
| 248 | |
| 249 /* Now we've got a cell (new or reused). Fill it in. */ | |
| 250 memcpy (&cell->gcvm.gcv, gcv, sizeof (XGCValues)); | |
| 251 cell->gcvm.mask = mask; | |
| 252 | |
| 253 /* Put the cell on the end of the list. */ | |
| 254 cell->next = 0; | |
| 255 cell->prev = cache->tail; | |
| 256 if (cache->tail) cache->tail->next = cell; | |
| 257 cache->tail = cell; | |
| 258 if (! cache->head) cache->head = cell; | |
| 259 | |
| 260 cache->create_count++; | |
| 261 #ifdef GCCACHE_HASH | |
| 262 /* Hash it in the table */ | |
| 263 puthash (&cell->gcvm, cell, cache->table); | |
| 264 #endif | |
| 265 | |
| 266 /* Now make and return the GC. */ | |
| 267 cell->gc = XCreateGC (cache->dpy, cache->window, mask, gcv); | |
| 268 | |
| 269 /* debug */ | |
| 270 assert (cell->gc == gc_cache_lookup (cache, gcv, mask)); | |
| 271 | |
| 3094 | 272 #if 0 |
| 273 debug_out ("Returning new GC: %08lx\n ", XE_GCONTEXT(cell)); | |
| 274 #endif | |
| 2587 | 275 return cell->gc; |
| 276 } | |
| 277 | |
| 278 | |
| 279 #ifdef DEBUG_XEMACS | |
| 280 | |
| 3094 | 281 /* FLAGS |
| 282 The flags argument is a bitwise or of any of the following: | |
| 283 | |
| 284 DGCCFLAG_SUMMARY Summary statistics for cache | |
| 285 DGCCFLAG_LIST_CELLS If summary is being printed, print cell IDs too. | |
| 286 DGCCFLAG_CELL_DETAILS If cell IDs are being printed, additionally | |
| 287 print the internal fields used and values. | |
| 288 | |
| 289 DGCCFLAG_DEFAULT A predefined combination giving whatever the | |
| 290 maintainers are currently interested in seeing. | |
| 291 */ | |
| 2587 | 292 void |
| 3094 | 293 describe_gc_cache (struct gc_cache *cache, int flags) |
| 2587 | 294 { |
| 295 int count = 0; | |
| 296 struct gc_cache_cell *cell = cache->head; | |
| 3094 | 297 |
| 298 if (! flags & DGCCFLAG_SUMMARY) return; | |
| 299 | |
| 2587 | 300 stderr_out ("\nsize: %d", cache->size); |
| 301 stderr_out ("\ncreated: %d", cache->create_count); | |
| 302 stderr_out ("\ndeleted: %d", cache->delete_count); | |
| 303 | |
| 3094 | 304 if (flags & DGCCFLAG_LIST_CELLS) |
| 305 while (cell) | |
| 306 { | |
| 307 struct gc_cache_cell *cell2; | |
| 308 int i = 0; | |
| 309 stderr_out ("\n%d:\t0x%lx GC: 0x%08lx hash: 0x%08lx\n", | |
| 310 count, (long) cell, (long) XE_GCONTEXT(cell), | |
| 311 gc_cache_hash (&cell->gcvm)); | |
| 312 | |
| 313 for (cell2 = cache->head; cell2; cell2 = cell2->next, i++) | |
| 314 if (count != i && | |
| 315 gc_cache_hash (&cell->gcvm) == gc_cache_hash (&cell2->gcvm)) | |
| 316 stderr_out ("\tHASH COLLISION with cell %d\n", i); | |
| 317 stderr_out ("\tmask: %8lx\n", cell->gcvm.mask); | |
| 318 | |
| 319 if (flags & DGCCFLAG_CELL_DETAILS) | |
| 320 { | |
| 2587 | 321 #define FROB(field) do { \ |
| 322 if ((int)cell->gcvm.gcv.field != (~0)) \ | |
| 323 stderr_out ("\t%-12s%8x\n", #field ":", (int)cell->gcvm.gcv.field); \ | |
| 324 } while (0) | |
| 3094 | 325 FROB (function); |
| 326 FROB (plane_mask); | |
| 327 FROB (foreground); | |
| 328 FROB (background); | |
| 329 FROB (line_width); | |
| 330 FROB (line_style); | |
| 331 FROB (cap_style); | |
| 332 FROB (join_style); | |
| 333 FROB (fill_style); | |
| 334 FROB (fill_rule); | |
| 335 FROB (arc_mode); | |
| 336 FROB (tile); | |
| 337 FROB (stipple); | |
| 338 FROB (ts_x_origin); | |
| 339 FROB (ts_y_origin); | |
| 340 FROB (font); | |
| 341 FROB (subwindow_mode); | |
| 342 FROB (graphics_exposures); | |
| 343 FROB (clip_x_origin); | |
| 344 FROB (clip_y_origin); | |
| 345 FROB (clip_mask); | |
| 346 FROB (dash_offset); | |
| 2587 | 347 #undef FROB |
| 3094 | 348 } |
| 2587 | 349 |
| 3094 | 350 count++; |
| 351 if (cell->next && cell == cache->tail) | |
| 352 stderr_out ("\nERROR! tail is here!\n\n"); | |
| 353 else if (!cell->next && cell != cache->tail) | |
| 354 stderr_out ("\nERROR! tail is not at the end\n\n"); | |
| 355 cell = cell->next; | |
| 356 } /* while (cell) */ | |
| 357 | |
| 2587 | 358 if (count != cache->size) |
| 359 stderr_out ("\nERROR! count should be %d\n\n", cache->size); | |
| 360 } | |
| 361 | |
| 362 #endif /* DEBUG_XEMACS */ |