|
0
|
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 hashtables. 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>
|
|
|
55 #include <X11/Xlib.h>
|
|
|
56 #include "xgccache.h"
|
|
|
57
|
|
|
58
|
|
|
59 #define GC_CACHE_SIZE 100
|
|
|
60
|
|
|
61 #define GCCACHE_HASH
|
|
|
62
|
|
|
63
|
|
|
64 #ifdef GCCACHE_HASH
|
|
|
65 #include "lisp.h"
|
|
|
66 #include "hash.h"
|
|
|
67 #endif
|
|
|
68
|
|
|
69 struct gcv_and_mask {
|
|
|
70 XGCValues gcv;
|
|
|
71 unsigned long mask;
|
|
|
72 };
|
|
|
73
|
|
|
74 struct gc_cache_cell {
|
|
|
75 GC gc;
|
|
|
76 struct gcv_and_mask gcvm;
|
|
|
77 struct gc_cache_cell *prev, *next;
|
|
|
78 };
|
|
|
79
|
|
|
80 struct gc_cache {
|
|
|
81 Display *dpy; /* used only as arg to XCreateGC/XFreeGC */
|
|
|
82 Window window; /* used only as arg to XCreateGC */
|
|
|
83 int size;
|
|
|
84 struct gc_cache_cell *head;
|
|
|
85 struct gc_cache_cell *tail;
|
|
|
86 #ifdef GCCACHE_HASH
|
|
|
87 c_hashtable table;
|
|
|
88 #endif
|
|
|
89
|
|
|
90 int create_count;
|
|
|
91 int delete_count;
|
|
|
92 };
|
|
|
93
|
|
|
94 #ifdef GCCACHE_HASH
|
|
|
95 static unsigned long
|
|
|
96 gc_cache_hash (CONST void *arg)
|
|
|
97 {
|
|
|
98 CONST struct gcv_and_mask *gcvm = (CONST struct gcv_and_mask *) arg;
|
|
|
99 unsigned long *longs = (unsigned long *) &gcvm->gcv;
|
|
|
100 unsigned long hash = gcvm->mask;
|
|
|
101 int i;
|
|
|
102 /* This could look at the mask and only use the used slots in the
|
|
|
103 hash code. That would win in that we wouldn't have to initialize
|
|
|
104 every slot of the gcv when calling gc_cache_lookup. But we need
|
|
|
105 the hash function to be as fast as possible; some timings should
|
|
|
106 be done. */
|
|
|
107 for (i = 0; i < (sizeof (XGCValues) / sizeof (unsigned long)); i++)
|
|
|
108 hash = (hash<<1) ^ *longs++;
|
|
|
109 return hash;
|
|
|
110 }
|
|
|
111
|
|
|
112 #endif /* GCCACHE_HASH */
|
|
|
113
|
|
|
114 static int
|
|
|
115 gc_cache_eql (CONST void *arg1, CONST void *arg2)
|
|
|
116 {
|
|
|
117 /* See comment in gc_cache_hash */
|
|
|
118 return (!memcmp (arg1, arg2, sizeof (struct gcv_and_mask)));
|
|
|
119 }
|
|
|
120
|
|
|
121 struct gc_cache *
|
|
|
122 make_gc_cache (Display *dpy, Window window)
|
|
|
123 {
|
|
|
124 struct gc_cache *cache =
|
|
|
125 (struct gc_cache *) xmalloc (sizeof (struct gc_cache));
|
|
|
126 cache->dpy = dpy;
|
|
|
127 cache->window = window;
|
|
|
128 cache->size = 0;
|
|
|
129 cache->head = cache->tail = 0;
|
|
|
130 cache->create_count = cache->delete_count = 0;
|
|
|
131 #ifdef GCCACHE_HASH
|
|
|
132 cache->table =
|
|
|
133 make_general_hashtable (GC_CACHE_SIZE, gc_cache_hash, gc_cache_eql);
|
|
|
134 #endif
|
|
|
135 return cache;
|
|
|
136 }
|
|
|
137
|
|
|
138 void
|
|
|
139 free_gc_cache (struct gc_cache *cache)
|
|
|
140 {
|
|
|
141 struct gc_cache_cell *rest, *next;
|
|
|
142 rest = cache->head;
|
|
|
143 while (rest)
|
|
|
144 {
|
|
|
145 XFreeGC (cache->dpy, rest->gc);
|
|
|
146 next = rest->next;
|
|
|
147 xfree (rest);
|
|
|
148 rest = next;
|
|
|
149 }
|
|
|
150 #ifdef GCCACHE_HASH
|
|
|
151 free_hashtable (cache->table);
|
|
|
152 #endif
|
|
|
153 xfree (cache);
|
|
|
154 }
|
|
|
155
|
|
|
156 GC
|
|
|
157 gc_cache_lookup (struct gc_cache *cache, XGCValues *gcv, unsigned long mask)
|
|
|
158 {
|
|
|
159 struct gc_cache_cell *cell, *next, *prev;
|
|
|
160 struct gcv_and_mask gcvm;
|
|
|
161
|
|
|
162 if ((!!cache->head) != (!!cache->tail)) abort ();
|
|
|
163 if (cache->head && (cache->head->prev || cache->tail->next)) abort ();
|
|
|
164
|
|
|
165 gcvm.mask = mask;
|
|
|
166 gcvm.gcv = *gcv; /* this copies... */
|
|
|
167
|
|
|
168 #ifdef GCCACHE_HASH
|
|
|
169
|
|
|
170 if (gethash (&gcvm, cache->table, (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 */
|
|
|
198 if (cell == cache->tail)
|
|
|
199 return cell->gc;
|
|
|
200
|
|
|
201 next = cell->next;
|
|
|
202 prev = cell->prev;
|
|
|
203 if (prev) prev->next = next;
|
|
|
204 if (next) next->prev = prev;
|
|
|
205 if (cache->head == cell) cache->head = next;
|
|
|
206 cell->next = 0;
|
|
|
207 cell->prev = cache->tail;
|
|
|
208 cache->tail->next = cell;
|
|
|
209 cache->tail = cell;
|
|
|
210 if (cache->head == cell) abort ();
|
|
|
211 if (cell->next) abort ();
|
|
|
212 if (cache->head->prev) abort ();
|
|
|
213 if (cache->tail->next) abort ();
|
|
|
214 return cell->gc;
|
|
|
215 }
|
|
|
216
|
|
|
217 /* else, cache miss. */
|
|
|
218
|
|
|
219 if (cache->size == GC_CACHE_SIZE)
|
|
|
220 /* Reuse the first cell on the list (least-recently-used).
|
|
|
221 Remove it from the list, and unhash it from the table.
|
|
|
222 */
|
|
|
223 {
|
|
|
224 cell = cache->head;
|
|
|
225 cache->head = cell->next;
|
|
|
226 cache->head->prev = 0;
|
|
|
227 if (cache->tail == cell) cache->tail = 0; /* only one */
|
|
|
228 XFreeGC (cache->dpy, cell->gc);
|
|
|
229 cache->delete_count++;
|
|
|
230 #ifdef GCCACHE_HASH
|
|
|
231 remhash (&cell->gcvm, cache->table);
|
|
|
232 #endif
|
|
|
233 }
|
|
|
234 else if (cache->size > GC_CACHE_SIZE)
|
|
|
235 abort ();
|
|
|
236 else
|
|
|
237 {
|
|
|
238 /* Allocate a new cell (don't put it in the list or table yet).
|
|
|
239 */
|
|
|
240 cell = (struct gc_cache_cell *) xmalloc (sizeof (struct gc_cache_cell));
|
|
|
241 cache->size++;
|
|
|
242 }
|
|
|
243
|
|
|
244 /* Now we've got a cell (new or reused). Fill it in. */
|
|
|
245 memcpy (&cell->gcvm.gcv, gcv, sizeof (XGCValues));
|
|
|
246 cell->gcvm.mask = mask;
|
|
|
247
|
|
|
248 /* Put the cell on the end of the list. */
|
|
|
249 cell->next = 0;
|
|
|
250 cell->prev = cache->tail;
|
|
|
251 if (cache->tail) cache->tail->next = cell;
|
|
|
252 cache->tail = cell;
|
|
|
253 if (! cache->head) cache->head = cell;
|
|
|
254
|
|
|
255 cache->create_count++;
|
|
|
256 #ifdef GCCACHE_HASH
|
|
|
257 /* Hash it in the table */
|
|
|
258 puthash (&cell->gcvm, cell, cache->table);
|
|
|
259 #endif
|
|
|
260
|
|
|
261 /* Now make and return the GC. */
|
|
|
262 cell->gc = XCreateGC (cache->dpy, cache->window, mask, gcv);
|
|
|
263
|
|
|
264 /* debug */
|
|
|
265 assert (cell->gc == gc_cache_lookup (cache, gcv, mask));
|
|
|
266
|
|
|
267 return cell->gc;
|
|
|
268 }
|
|
|
269
|
|
|
270
|
|
|
271 #if 1
|
|
|
272
|
|
|
273 #include <stdio.h>
|
|
|
274
|
|
|
275 void describe_gc_cache (struct gc_cache *cache);
|
|
|
276 void
|
|
|
277 describe_gc_cache (struct gc_cache *cache)
|
|
|
278 {
|
|
|
279 int count = 0;
|
|
|
280 struct gc_cache_cell *cell = cache->head;
|
|
|
281 stderr_out ("\nsize: %d", cache->size);
|
|
|
282 stderr_out ("\ncreated: %d", cache->create_count);
|
|
|
283 stderr_out ("\ndeleted: %d", cache->delete_count);
|
|
|
284 while (cell)
|
|
|
285 {
|
|
|
286 struct gc_cache_cell *cell2;
|
|
|
287 int i = 0;
|
|
|
288 stderr_out ("\n%d:\t0x%lx GC: 0x%08lx hash: 0x%08lx\n",
|
|
|
289 count, (long) cell, (long) cell->gc, gc_cache_hash (&cell->gcvm));
|
|
|
290 for (cell2 = cache->head; cell2; cell2 = cell2->next, i++)
|
|
|
291 if (count != i &&
|
|
|
292 gc_cache_hash (&cell->gcvm) == gc_cache_hash (&cell2->gcvm))
|
|
|
293 stderr_out ("\tHASH COLLISION with cell %d\n", i);
|
|
|
294 stderr_out ("\tmask: %8lx\n", cell->gcvm.mask);
|
|
|
295 #define F(x) (int)cell->gcvm.gcv.x
|
|
|
296 #define G(w,x) if (F(x) != (~0)) stderr_out ("\t%-12s%8x\n", w, F(x))
|
|
|
297 G("function:", function);
|
|
|
298 G("plane_mask:", plane_mask);
|
|
|
299 G("foreground:", foreground);
|
|
|
300 G("background:", background);
|
|
|
301 G("line_width:", line_width);
|
|
|
302 G("line_style:", line_style);
|
|
|
303 G("cap_style:", cap_style);
|
|
|
304 G("join_style:", join_style);
|
|
|
305 G("fill_style:", fill_style);
|
|
|
306 G("fill_rule:", fill_rule);
|
|
|
307 G("arc_mode:", arc_mode);
|
|
|
308 G("tile:", tile);
|
|
|
309 G("stipple:", stipple);
|
|
|
310 G("tsx_origin:", ts_x_origin);
|
|
|
311 G("tsy_origin:", ts_y_origin);
|
|
|
312 G("font:", font);
|
|
|
313 G("subwindow:", subwindow_mode);
|
|
|
314 G("gexposures:", graphics_exposures);
|
|
|
315 G("clip_x:", clip_x_origin);
|
|
|
316 G("clip_y:", clip_y_origin);
|
|
|
317 G("clip_mask:", clip_mask);
|
|
|
318 G("dash_off:", dash_offset);
|
|
|
319 #undef F
|
|
|
320 #undef G
|
|
|
321 count++;
|
|
|
322 if (cell->next && cell == cache->tail)
|
|
|
323 stderr_out ("\nERROR! tail is here!\n\n");
|
|
|
324 else if (!cell->next && cell != cache->tail)
|
|
|
325 stderr_out ("\nERROR! tail is not at the end\n\n");
|
|
|
326 cell = cell->next;
|
|
|
327 }
|
|
|
328 if (count != cache->size)
|
|
|
329 stderr_out ("\nERROR! count should be %d\n\n", cache->size);
|
|
|
330 }
|
|
|
331
|
|
|
332 #endif
|
